Scholars@Duke
Thomas Mitchell-Olds

Thomas Mitchell-Olds

Newman Ivey White Distinguished Professor Emeritus of Biology
Biology
tmo1@duke.edu
Duke Box 90338, Durham, NC 27708-0338
French Science Center 3101, Durham, NC 27708

Selected Publications

Increasing Aridity May Threaten the Maintenance of a Plant Defence Polymorphism.

Journal Article Ecology letters · January 2025 It is unclear how environmental change influences standing genetic variation in wild populations. Here, we characterised environmental conditions that protect versus erode polymorphic chemical defences in Boechera stricta (Brassicaceae), a short-lived pere ... Full text Cite

Soil variation among natural habitats alters glucosinolate content in a wild perennial mustard.

Journal Article Journal of experimental botany · March 2023 Baseline levels of glucosinolates-important defensive phytochemicals in brassicaceous plants-are determined by both genotype and environment. However, the ecological causes of glucosinolate plasticity are not well characterized. Fertilization is known to a ... Full text Cite

Are genetic variation and demographic performance linked?

Journal Article Evolutionary applications · November 2022 Quantifying relationships between genetic variation and population viability is important from both basic biological and applied conservation perspectives, yet few populations have been monitored with both long-term demographic and population genetics appr ... Full text Cite

The Boechera model system for evolutionary ecology.

Journal Article American journal of botany · November 2022 Model systems in biology expand the research capacity of individuals and the community. Closely related to Arabidopsis, the genus Boechera has emerged as an important ecological model owing to the ability to integrate across molecular, functional, and eco- ... Full text Cite

Adaptive responses drive the success of polyploid yellowcresses (Rorippa, Brassicaceae) in the Hengduan Mountains, a temperate biodiversity hotspot.

Journal Article Plant diversity · September 2022 Polyploids contribute substantially to plant evolution and biodiversity; however, the mechanisms by which they succeed are still unclear. According to the polyploid adaptation hypothesis, successful polyploids spread by repeated adaptive responses t ... Full text Cite

Globally Relaxed Selection and Local Adaptation in Boechera stricta.

Journal Article Genome biology and evolution · April 2022 The strength of selection varies among populations and across the genome, but the determinants of efficacy of selection remain unclear. In this study, we used whole-genome sequencing data from 467 Boechera stricta accessions to quantify the strength of sel ... Full text Cite

Ecological factors influence balancing selection on leaf chemical profiles of a wildflower.

Journal Article Nature ecology & evolution · August 2021 Balancing selection is frequently invoked as a mechanism that maintains variation within and across populations. However, there are few examples of balancing selection operating on loci underpinning complex traits, which frequently display high levels of v ... Full text Cite

An epigenetic pathway in rice connects genetic variation to anaerobic germination and seedling establishment.

Journal Article Plant physiology · June 2021 Featured Publication Rice production is shifting from transplanting seedlings to direct sowing of seeds. Following heavy rains, directly sown seeds may need to germinate under anaerobic environments, but most rice (Oryza sativa) genotypes cannot survive these conditions. To id ... Full text Cite

Genetic architecture and adaptation of flowering time among environments.

Journal Article The New phytologist · May 2021 Featured Publication The genetic basis of flowering time changes across environments, and pleiotropy may limit adaptive evolution of populations in response to local conditions. However, little information is known about how genetic architecture changes among environments. We ... Full text Cite

The ecological, genetic and genomic architecture of local adaptation and population differentiation in Boechera stricta.

Journal Article Proceedings. Biological sciences · April 2021 Differential local adaptation restricts gene flow between populations inhabiting distinct environments, resulting in isolation by adaptation. In addition to the statistical inferences of genotype-environment associations, an integrative approach is needed ... Full text Cite

The Evolution of Sex is Tempered by Costly Hybridization in Boechera (Rock Cress).

Journal Article The Journal of heredity · March 2021 Featured Publication Despite decades of research, the evolution of sex remains an enigma in evolutionary biology. Typically, research addresses the costs of sex and asexuality to characterize the circumstances favoring one reproductive mode. Surprisingly few studies address th ... Full text Cite

Identifying the fitness consequences of sex in complex natural environments.

Journal Article Evolution letters · December 2020 In the natural world, sex prevails, despite its costs. Although much effort has been dedicated to identifying the intrinsic costs of sex (e.g., the cost of males), few studies have identified the ecological fitness consequences of sex. Furthermore, correla ... Full text Cite

Chromosomal Evolution and Apomixis in the Cruciferous Tribe Boechereae.

Journal Article Frontiers in plant science · January 2020 The mustard family (Brassicaceae) comprises several dozen monophyletic clades usually ranked as tribes. The tribe Boechereae plays a prominent role in plant research due to the incidence of apomixis and its close relationship to Arabidopsis. This tr ... Full text Cite

Correction to: Ancient polymorphisms contribute to genome-wide variation by long-term balancing selection and divergent sorting in Boechera stricta.

Journal Article Genome biology · August 2019 Following publication of the original article [1], the authors reported that the Availability of data and materials section required updating. The updated text reads as follows. ... Full text Cite

Ancient polymorphisms contribute to genome-wide variation by long-term balancing selection and divergent sorting in Boechera stricta.

Journal Article Genome biology · June 2019 BackgroundGenomic variation is widespread, and both neutral and selective processes can generate similar patterns in the genome. These processes are not mutually exclusive, so it is difficult to infer the evolutionary mechanisms that govern popula ... Full text Cite

Antagonistic selection and pleiotropy constrain the evolution of plant chemical defenses.

Journal Article Evolution; international journal of organic evolution · May 2019 When pleiotropy is present, genetic correlations may constrain the evolution of ecologically important traits. We used a quantitative genetics approach to investigate constraints on the evolution of secondary metabolites in a wild mustard, Boechera stricta ... Full text Cite

Ecological differentiation facilitates fine-scale coexistence of sexual and asexual Boechera.

Journal Article American journal of botany · December 2018 Premise of the studyEcological differentiation (ED) between sexual and asexual organisms may permit the maintenance of reproductive polymorphism. Several studies of sexual/asexual ED in plants have shown that the geographic ranges of asexuals exte ... Full text Cite

DIACYLGLYCEROL ACYLTRANSFERASE1 Contributes to Freezing Tolerance.

Journal Article Plant physiology · August 2018 Freezing limits plant growth and crop productivity, and plant species in temperate zones have the capacity to develop freezing tolerance through complex modulation of gene expression affecting various aspects of metabolism and physiology. While many compon ... Full text Cite

Physiological mechanisms contributing to the QTL qDTY3.2 effects on improved performance of rice Moroberekan x Swarna BC2F3:4 lines under drought.

Journal Article Rice (New York, N.Y.) · July 2018 BackgroundTraditional rice (Oryza sativa) varieties are valuable resources for the improvement of drought resistance. qDTY3.2 is a drought-yield quantitative trait locus that was identified in a population derived from the traditional v ... Full text Cite

Plasticity of plant defense and its evolutionary implications in wild populations of Boechera stricta.

Journal Article Evolution; international journal of organic evolution · May 2018 Phenotypic plasticity is thought to impact evolutionary trajectories by shifting trait values in a direction that is either favored by natural selection ("adaptive" plasticity) or disfavored ("nonadaptive" plasticity). However, it is unclear how commonly e ... Full text Cite

Assembly of the Boechera retrofracta Genome and Evolutionary Analysis of Apomixis-Associated Genes.

Journal Article Genes · March 2018 Closely related to the model plant Arabidopsis thaliana, the genus Boechera is known to contain both sexual and apomictic species or accessions. Boechera retrofracta is a diploid sexually reproducing species and is thought to be an anc ... Full text Cite

The Functional Change and Deletion of FLC Homologs Contribute to the Evolution of Rapid Flowering in Boechera stricta.

Journal Article Frontiers in plant science · January 2018 Differences in the timing of vegetative-to-reproductive phase transition have evolved independently and repeatedly in different plant species. Due to their specific biological functions and positions in pathways, some genes are important targets of repeate ... Full text Cite

Balancing selection and trans-specific polymorphisms.

Journal Article Genome biology · December 2017 Balancing selection maintains variation for evolution. A recent study investigated the extent of balancing selection in two Brassicaceae species and highlighted its importance for adaptation. ... Full text Cite

Publisher correction: Young inversion with multiple linked QTLs under selection in a hybrid zone.

Journal Article Nature ecology & evolution · October 2017 In Fig. 5 of the version of this Article originally published, the final number on the x axes of each panel was incorrectly written as 1.5; it should have read 7.5. This has now been corrected in all versions of the Article. ... Full text Cite

Young inversion with multiple linked QTLs under selection in a hybrid zone.

Journal Article Nature ecology & evolution · April 2017 Fixed chromosomal inversions can reduce gene flow and promote speciation in two ways: by suppressing recombination and by carrying locally favoured alleles at multiple loci. However, it is unknown whether favoured mutations slowly accumulate on older inver ... Full text Open Access Cite

Testing the optimal defense hypothesis in nature: Variation for glucosinolate profiles within plants.

Journal Article PloS one · January 2017 Plants employ highly variable chemical defenses against a broad community of herbivores, which vary in their susceptibilities to specific compounds. Variation in chemical defenses within the plant has been found in many species; the ecological and evolutio ... Full text Cite

Host genotype and age shape the leaf and root microbiomes of a wild perennial plant

Journal Article Nat Commun · July 12, 2016 Bacteria living on and in leaves and roots influence many aspects of plant health, so the extent of a plant/'s genetic control over its microbiota is of great interest to crop breeders and evolutionary biologists. Laboratory-based studies, because they poo ... Open Access Link to item Cite

QTL Mapping in Three Rice Populations Uncovers Major Genomic Regions Associated with African Rice Gall Midge Resistance.

Journal Article PloS one · January 2016 African rice gall midge (AfRGM) is one of the most destructive pests of irrigated and lowland African ecologies. This study aimed to identify the quantitative trait loci (QTL) associated with AfRGM pest incidence and resistance in three independent bi-pare ... Full text Open Access Cite

Natural variation, differentiation, and genetic trade-offs of ecophysiological traits in response to water limitation in Brachypodium distachyon and its descendent allotetraploid B. hybridum (Poaceae).

Journal Article Evolution; international journal of organic evolution · October 2015 Differences in tolerance to water stress may underlie ecological divergence of closely related ploidy lineages. However, the mechanistic basis of physiological variation governing ecogeographical cytotype segregation is not well understood. Here, using Bra ... Full text Cite

Understanding rice adaptation to varying agro-ecosystems: trait interactions and quantitative trait loci.

Journal Article BMC genetics · August 2015 BackgroundInteraction and genetic control for traits influencing the adaptation of the rice crop to varying environments was studied in a mapping population derived from parents (Moroberekan and Swarna) contrasting for drought tolerance, yield pot ... Full text Cite

Identification of quantitative trait loci and a candidate locus for freezing tolerance in controlled and outdoor environments in the overwintering crucifer Boechera stricta.

Journal Article Plant, cell & environment · November 2014 Development of chilling and freezing tolerance is complex and can be affected by photoperiod, temperature and photosynthetic performance; however, there has been limited research on the interaction of these three factors. We evaluated 108 recombinant inbre ... Full text Cite

Unifying genetic canalization, genetic constraint, and genotype-by-environment interaction: QTL by genomic background by environment interaction of flowering time in Boechera stricta.

Journal Article PLoS genetics · October 2014 Natural populations exhibit substantial variation in quantitative traits. A quantitative trait is typically defined by its mean and variance, and to date most genetic mapping studies focus on loci altering trait means but not (co)variances. For single trai ... Full text Cite

Genome diversity in Brachypodium distachyon: deep sequencing of highly diverse inbred lines.

Journal Article The Plant journal : for cell and molecular biology · August 2014 Brachypodium distachyon is small annual grass that has been adopted as a model for the grasses. Its small genome, high-quality reference genome, large germplasm collection, and selfing nature make it an excellent subject for studies of natural variation. W ... Full text Cite

Large-scale adaptive divergence in Boechera fecunda, an endangered wild relative of Arabidopsis.

Journal Article Ecology and evolution · August 2014 Many biological species are threatened with extinction because of a number of factors such as climate change and habitat loss, and their preservation depends on an accurate understanding of the extent of their genetic variability within and among populatio ... Full text Cite

Natural soil microbes alter flowering phenology and the intensity of selection on flowering time in a wild Arabidopsis relative.

Journal Article Ecology letters · June 2014 Plant phenology is known to depend on many different environmental variables, but soil microbial communities have rarely been acknowledged as possible drivers of flowering time. Here, we tested separately the effects of four naturally occurring soil microb ... Full text Cite

Genetic variation for resistance to herbivores and plant pathogens: Hypotheses, mechanisms and evolutionary implications

Journal Article Plant Pathology · December 1, 2013 The interactions between plants and enemies employ a variety of mechanisms, which in turn affect the long-term evolutionary histories of the interacting species. Different patterns of interactions determine not only the selective forces acting on individua ... Full text Cite

Selection on QTL and complex traits in complex environments.

Journal Article Molecular ecology · July 2013 Understanding genetic variation for complex traits in heterogeneous environments is a fundamental problem in biology. In this issue of Molecular Ecology, Fournier-Level et al. (2013) analyse quantitative trait loci (QTL)influencing ecologically important p ... Full text Cite

Complex trait divergence contributes to environmental niche differentiation in ecological speciation of Boechera stricta.

Journal Article Molecular ecology · April 2013 Ecological factors may contribute to reproductive isolation if differential local adaptation causes immigrant or hybrid fitness reduction. Because local adaptation results from the interaction between natural selection and adaptive traits, it is crucial to ... Full text Cite

3D phenotyping and quantitative trait locus mapping identify core regions of the rice genome controlling root architecture.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · April 2013 Identification of genes that control root system architecture in crop plants requires innovations that enable high-throughput and accurate measurements of root system architecture through time. We demonstrate the ability of a semiautomated 3D in vivo imagi ... Full text Cite

Genetic trade-offs and conditional neutrality contribute to local adaptation.

Journal Article Molecular ecology · February 2013 Divergent natural selection promotes local adaptation and can lead to reproductive isolation of populations in contrasting environments; however, the genetic basis of local adaptation remains largely unresolved in natural populations. Local adaptation migh ... Full text Cite

Signatures of demography and recombination at coding genes in naturally-distributed populations of Arabidopsis lyrata subsp. petraea.

Journal Article PloS one · January 2013 Demography impacts the observed standing level of genetic diversity present in populations. Distinguishing the relative impacts of demography from selection requires a baseline of expressed gene variation in naturally occurring populations. Six nuclear gen ... Full text Cite

Evolution of flux control in the glucosinolate pathway in Arabidopsis thaliana.

Journal Article Molecular biology and evolution · January 2013 Network characteristics of biochemical pathways are believed to influence the rate of evolutionary change in constituent enzymes. One characteristic that may affect rate heterogeneity is control of the amount of product produced by a biochemical pathway or ... Full text Cite

The Reference Genome of the Halophytic Plant Eutrema salsugineum.

Journal Article Frontiers in plant science · January 2013 Halophytes are plants that can naturally tolerate high concentrations of salt in the soil, and their tolerance to salt stress may occur through various evolutionary and molecular mechanisms. Eutrema salsugineum is a halophytic species in the Brassicaceae t ... Full text Cite

Environmental adaptation contributes to gene polymorphism across the Arabidopsis thaliana genome.

Journal Article Molecular biology and evolution · December 2012 The level of within-species polymorphism differs greatly among genes in a genome. Many genomic studies have investigated the relationship between gene polymorphism and factors such as recombination rate or expression pattern. However, the polymorphism of a ... Full text Cite

Adaptive evolution: evaluating empirical support for theoretical predictions.

Journal Article Nature reviews. Genetics · December 2012 Adaptive evolution is shaped by the interaction of population genetics, natural selection and underlying network and biochemical constraints. Variation created by mutation, the raw material for evolutionary change, is translated into phenotypes by flux thr ... Full text Cite

The calmodulin-binding transcription factor SIGNAL RESPONSIVE1 is a novel regulator of glucosinolate metabolism and herbivory tolerance in Arabidopsis.

Journal Article Plant & cell physiology · December 2012 The Arabidopsis Ca(2+)/calmodulin (CaM)-binding transcription factor SIGNAL RESPONSIVE1 (AtSR1/CAMTA3) was previously identified as a key negative regulator of plant immune responses. Here, we report a new role for AtSR1 as a critical component of plant de ... Full text Cite

Phenotypic plasticity and adaptive evolution contribute to advancing flowering phenology in response to climate change.

Conference Proceedings. Biological sciences · September 2012 Anthropogenic climate change has already altered the timing of major life-history transitions, such as the initiation of reproduction. Both phenotypic plasticity and adaptive evolution can underlie rapid phenological shifts in response to climate change, b ... Full text Cite

A gain-of-function polymorphism controlling complex traits and fitness in nature.

Journal Article Science (New York, N.Y.) · August 2012 Identification of the causal genes that control complex trait variation remains challenging, limiting our appreciation of the evolutionary processes that influence polymorphisms in nature. We cloned a quantitative trait locus that controls plant defensive ... Full text Cite

Origin, fate, and architecture of ecologically relevant genetic variation.

Journal Article Current opinion in plant biology · April 2012 Recent advances in molecular genetics combined with field manipulations are yielding new insight into the origin, evolutionary fate, and genetic architecture of phenotypic variation in natural plant populations, with two surprising implications for the evo ... Full text Cite

Environmental aridity is associated with cytotype segregation and polyploidy occurrence in Brachypodium distachyon (Poaceae).

Journal Article The New phytologist · February 2012 • The ecological and adaptive significance of plant polyploidization is not well understood and no clear pattern of association between polyploid frequency and environment has emerged. Climatic factors are expected to predict cytotype distribution. However ... Full text Cite

On the origin and evolution of apomixis in Boechera

Journal Article New Phytologist · 2012 Cite

Boechera, a model system for ecological genomics.

Journal Article Molecular ecology · December 2011 The selection and development of a study system for evolutionary and ecological functional genomics (EEFG) depend on a variety of factors. Here, we present the genus Boechera as an exemplary system with which to address ecological and evolutionary question ... Full text Cite

Quantifying effects of environmental and geographical factors on patterns of genetic differentiation.

Journal Article Molecular ecology · November 2011 Elucidating the factors influencing genetic differentiation is an important task in biology, and the relative contribution from natural selection and genetic drift has long been debated. In this study, we used a regression-based approach to simultaneously ... Full text Cite

Repeated phenotypic changes highlight molecular targets of convergent evolution.

Journal Article Genome biology · August 2011 How predictable is evolution at the molecular level? An example of repeated evolution in rice and Brassica illustrates how selection might preferentially target certain genes and mutations. ... Full text Cite

Evolutionary genetics of plant adaptation.

Journal Article Trends in genetics : TIG · July 2011 Plants provide unique opportunities to study the mechanistic basis and evolutionary processes of adaptation to diverse environmental conditions. Complementary laboratory and field experiments are important for testing hypotheses reflecting long-term ecolog ... Full text Cite

Ecological genetics and genomics of plant defenses: Evidence and approaches.

Journal Article Functional ecology · April 2011 Herbivores exert significant selection on plants, and plants have evolved a variety of constitutive and inducible defenses to resist and tolerate herbivory. Assessing the genetic mechanisms that influence defenses against herbivores will deepen our underst ... Full text Cite

Life-history QTLS and natural selection on flowering time in Boechera stricta, a perennial relative of Arabidopsis.

Journal Article Evolution; international journal of organic evolution · March 2011 Plants must precisely time flowering to capitalize on favorable conditions. Although we know a great deal about the genetic basis of flowering phenology in model species under controlled conditions, the genetic architecture of this ecologically important t ... Full text Cite

Evolutionary and Ecological Genomics of Non-Model Plants.

Journal Article Journal of systematics and evolution · January 2011 Dissecting evolutionary dynamics of ecologically important traits is a long-term challenge for biologists. Attempts to understand natural variation and molecular mechanisms have motivated a move from laboratory model systems to non-model systems in diverse ... Full text Cite

Beyond QTL cloning.

Journal Article PLoS genetics · November 2010 Full text Open Access Cite

Variation and fitness costs for tolerance to different types of herbivore damage in Boechera stricta genotypes with contrasting glucosinolate structures.

Journal Article The New phytologist · October 2010 • Analyses of plant tolerance in response to different modes of herbivory are essential to an understanding of plant defense evolution, yet are still scarce. Allocation costs and trade-offs between tolerance and plant chemical defenses may influence geneti ... Full text Cite

Genome wide analyses reveal little evidence for adaptive evolution in many plant species.

Journal Article Molecular biology and evolution · August 2010 The relative contribution of advantageous and neutral mutations to the evolutionary process is a central problem in evolutionary biology. Current estimates suggest that whereas Drosophila, mice, and bacteria have undergone extensive adaptive evolution, hom ... Full text Cite

Population history in Arabidopsis halleri using multilocus analysis.

Journal Article Molecular ecology · August 2010 A. halleri is a psuedometallophyte with a patchy distribution in Europe and is often spread by human activity. To determine the population history and whether this history is consistent with potential human effects, we surveyed nucleotide variation using 2 ... Full text Cite

Natural variation of flowering time and vernalization responsiveness in Brachypodium distachyon

Journal Article Bioenergy Research · February 1, 2010 Dedicated bioenergy crops require certain characteristics to be economically viable and environmentally sustainable. Perennial grasses, which can provide large amounts of biomass over multiple years, are one option being investigated to grow on marginal ag ... Full text Cite

Complex-trait analysis in plants.

Journal Article Genome biology · January 2010 Two recent studies in Arabidopsis have identified quantitative trait loci (QTLs) by population- association and family-based studies, respectively, providing further data on the genetic architecture of complex-trait variation in plants. ... Full text Cite

Life history in a model system: opening the black box with Arabidopsis thaliana.

Journal Article Ecology letters · July 2009 A broad research programme in Arabidopsis thaliana has provided estimates of selection on specific alleles in specific contexts, and identified geographic patterns of alleles in genes linked to timing of flowering. A closely related field has successfully ... Full text Cite

Local adaptation in European populations of Arabidopsis lyrata (Brassicaceae).

Journal Article American journal of botany · June 2009 We studied local adaptation to contrasting environments using an organism that is emerging as a model for evolutionary plant biology-the outcrossing, perennial herb Arabidopsis lyrata subsp. petraea (Brassicaceae). With reciprocal transplant experiments, w ... Full text Cite

Ecological genomics of Boechera stricta: identification of a QTL controlling the allocation of methionine- vs branched-chain amino acid-derived glucosinolates and levels of insect herbivory.

Journal Article Heredity · May 2009 In the Brassicaceae, glucosinolates influence the feeding, reproduction and development of many insect herbivores. Glucosinolate production and effects on herbivore feeding have been extensively studied in the model species, Arabidopsis thaliana and Brassi ... Full text Cite

Multilocus patterns of nucleotide diversity, population structure and linkage disequilibrium in Boechera stricta, a wild relative of Arabidopsis.

Journal Article Genetics · March 2009 Information about polymorphism, population structure, and linkage disequilibrium (LD) is crucial for association studies of complex trait variation. However, most genomewide studies have focused on model systems, with very few analyses of undisturbed natur ... Full text Cite

A novel 2-oxoacid-dependent dioxygenase involved in the formation of the goiterogenic 2-hydroxybut-3-enyl glucosinolate and generalist insect resistance in Arabidopsis,.

Journal Article Plant physiology · December 2008 Glucosinolates are secondary metabolites found almost exclusively in the order Brassicales. They are synthesized from a variety of amino acids and can have numerous side chain modifications that control biological function. We investigated the biosynthesis ... Full text Cite

Genetics of drought adaptation in Arabidopsis thaliana II. QTL analysis of a new mapping population, KAS-1 x TSU-1.

Journal Article Evolution; international journal of organic evolution · December 2008 Despite compelling evidence that adaptation to local climate is common in plant populations, little is known about the evolutionary genetics of traits that contribute to climatic adaptation. A screen of natural accessions of Arabidopsis thaliana revealed T ... Full text Cite

The shrunken genome of Arabidopsis thaliana

Journal Article Plant systematics and evolution = Entwicklungsgeschichte und Systematik der Pflanzen · July 2008 This paper examines macro and micro-level patterns of genome size evolution in the Brassicaceae. A phylogeny of 25 relatives of Arabidopsis thaliana was reconstructed using four molecular markers under both parsimony and Bayesian methods. Reconstruction of ... Full text Cite

From genotype to phenotype: systems biology meets natural variation.

Journal Article Science (New York, N.Y.) · April 2008 The promise that came with genome sequencing was that we would soon know what genes do, particularly genes involved in human diseases and those of importance to agriculture. We now have the full genomic sequence of human, chimpanzee, mouse, chicken, dog, w ... Full text Cite

Evolutionary and ecological functional genomics.

Journal Article Heredity · February 2008 Full text Cite

The genetic basis of a plant-insect coevolutionary key innovation.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · December 2007 Ehrlich and Raven formally introduced the concept of stepwise coevolution using butterfly and angiosperm interactions in an attempt to account for the impressive biological diversity of these groups. However, many biologists currently envision butterflies ... Full text Cite

Which evolutionary processes influence natural genetic variation for phenotypic traits?

Journal Article Nature reviews. Genetics · November 2007 Although many studies provide examples of evolutionary processes such as adaptive evolution, balancing selection, deleterious variation and genetic drift, the relative importance of these selective and stochastic processes for phenotypic variation within a ... Full text Cite

Different transcript patterns in response to specialist and generalist herbivores in the wild Arabidopsis relative Boechera divaricarpa.

Journal Article PloS one · October 2007 BackgroundPlants defend themselves against herbivorous insects, utilizing both constitutive and inducible defenses. Induced defenses are controlled by several phytohormone-mediated signaling pathways. Here, we analyze transcriptional changes in th ... Full text Cite

High genetic diversity and population differentiation in Boechera fecunda, a rare relative of Arabidopsis.

Journal Article Molecular ecology · October 2007 Conservation of endangered species becomes a critical issue with the increasing rates of extinction. In this study, we use 13 microsatellite loci and 27 single-copy nuclear loci to investigate the population genetics of Boechera fecunda, a rare relative of ... Full text Cite

Diploid apomicts of the Boechera holboellii complex display large-scale chromosome substitutions and aberrant chromosomes.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · August 2007 We conducted a cytogenetic study of sexual lines of Boechera stricta and Boechera holboellii (2n = 14) and seven diploid apomictic accessions of their interspecific hybrid Boechera divaricarpa and B. holboellii (2n = 14 or 15). By studying chromosome morph ... Full text Cite

Population genetic inference using a fixed number of segregating sites: a reassessment.

Journal Article Genetical research · August 2007 Coalescent theory is commonly used to perform population genetic inference at the nucleotide level. Here, we examine the procedure that fixes the number of segregating sites (henceforth the FS procedure). In this approach a fixed number of segregating site ... Full text Cite

Mapping of QTL for resistance against the crucifer specialist herbivore Pieris brassicae in a new Arabidopsis inbred line population, Da(1)-12 x Ei-2.

Journal Article PloS one · June 2007 BackgroundIn Arabidopsis thaliana and other crucifers, the glucosinolate-myrosinase system contributes to resistance against herbivory by generalist insects. As yet, it is unclear how crucifers defend themselves against crucifer-specialist insect ... Full text Cite

Comparative genetic mapping in Boechera stricta, a close relative of Arabidopsis.

Journal Article Plant physiology · May 2007 The angiosperm family Brassicaceae contains both the research model Arabidopsis (Arabidopsis thaliana) and the agricultural genus Brassica. Comparative genomics in the Brassicaceae has largely focused on direct comparisons between Arabidopsis and the speci ... Full text Cite

Comparative genomics in the Brassicaceae: a family-wide perspective.

Journal Article Current opinion in plant biology · April 2007 Comparative genomics of Arabidopsis relatives has great potential to improve our understanding of molecular function and evolutionary processes. Recent studies of phylogenetic relationships within Brassicaceae and the publication of a new tribal classifica ... Full text Cite

Mlcoalsim: multilocus coalescent simulations.

Journal Article Evolutionary bioinformatics online · March 2007 Coalescent theory is a powerful tool for population geneticists as well as molecular biologists interested in understanding the patterns and levels of DNA variation. Using coalescent Monte Carlo simulations it is possible to obtain the empirical distributi ... Cite

Cis-regulatory evolution of chalcone-synthase expression in the genus Arabidopsis.

Journal Article Genetics · December 2006 The contribution of cis-regulation to adaptive evolutionary change is believed to be essential, yet little is known about the evolutionary rules that govern regulatory sequences. Here, we characterize the short-term evolutionary dynamics of a cis-regulator ... Full text Cite

The ABC's of comparative genomics in the Brassicaceae: building blocks of crucifer genomes.

Journal Article Trends in plant science · November 2006 In this review we summarize recent advances in our understanding of phylogenetics, polyploidization and comparative genomics in the family Brassicaceae. These findings pave the way for a unified comparative genomic framework. We integrate several of these ... Full text Cite

Glucosinolate and trichome defenses in a natural Arabidopsis lyrata population.

Journal Article Journal of chemical ecology · November 2006 Glucosinolates (GS) and trichomes contribute to plant resistance against insect herbivores in the model Arabidopsis thaliana. The functional and genetic characteristics of herbivore defense, however, can differ even between closely related species. In a qu ... Full text Cite

Population genetic structure of Arabidopsis lyrata in Europe.

Journal Article Molecular ecology · September 2006 Population genetic theory predicts that the self-incompatible and perennial herb, Arabidopsis lyrata, will have a genetic structure that differs from the self-fertilizing, annual Arabidopsis thaliana. We quantified the genetic structure for eight populatio ... Full text Cite

Natural variation in MAM within and between populations of Arabidopsis lyrata determines glucosinolate phenotype.

Journal Article Genetics · July 2006 The genetic variation that underlies the glucosinolate phenotype of Arabidopsis lyrata ssp. petraea was investigated between and within populations. A candidate glucosinolate biosynthetic locus (MAM, containing methylthioalkylmalate synthase genes) was map ... Full text Cite

Genetic mechanisms and evolutionary significance of natural variation in Arabidopsis.

Journal Article Nature · June 2006 Genomic studies of natural variation in model organisms provide a bridge between molecular analyses of gene function and evolutionary investigations of adaptation and natural selection. In the model plant species Arabidopsis thaliana, recent studies of nat ... Full text Cite

Positive selection driving diversification in plant secondary metabolism.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · June 2006 In Arabidopsis thaliana and related plants, glucosinolates are a major component in the blend of secondary metabolites and contribute to resistance against herbivorous insects. Methylthioalkylmalate synthases (MAM) encoded at the MAM gene cluster control a ... Full text Cite

Independent ancient polyploidy events in the sister families Brassicaceae and Cleomaceae.

Journal Article The Plant cell · May 2006 Recent studies have elucidated the ancient polyploid history of the Arabidopsis thaliana (Brassicaceae) genome. The studies concur that there was at least one polyploidy event occurring some 14.5 to 86 million years ago (Mya), possibly near the divergence ... Full text Cite

Expression profiling and local adaptation of Boechera holboellii populations for water use efficiency across a naturally occurring water stress gradient.

Journal Article Molecular ecology · April 2006 We studied the physiological basis of local adaptation to drought in Boechera holboellii, a perennial relative of Arabidopsis thaliana, and used cDNA-AFLPs to identify candidate genes showing differential expression in these populations. We compared two po ... Full text Cite

Comparative genomics as a tool for gene discovery.

Journal Article Current opinion in biotechnology · April 2006 With the increasing availability of data from multiple eukaryotic genome sequencing projects, attention has focused on interspecific comparisons to discover novel genes and transcribed genomic sequences. Generally, these extrinsic strategies combine ab ini ... Full text Cite

Partial shotgun sequencing of the Boechera stricta genome reveals extensive microsynteny and promoter conservation with Arabidopsis.

Journal Article Plant physiology · April 2006 Comparative genomics provides insight into the evolutionary dynamics that shape discrete sequences as well as whole genomes. To advance comparative genomics within the Brassicaceae, we have end sequenced 23,136 medium-sized insert clones from Boechera stri ... Full text Cite

Geographic patterns of microsatellite variation in Boechera stricta, a close relative of Arabidopsis.

Journal Article Molecular ecology · February 2006 The genus Boechera is a widespread North American group with great potential for studies of ecology and evolution: Boechera is closely related to Arabidopsis and exhibits different ecological and reproductive strategies. Boechera stricta (previously Arabis ... Full text Cite

Ecological and evolutionary genomics of populations in nature

Journal Article Molecular Ecology · 2006 Cite

Asexual reproduction in a close relative of Arabidopsis: a genetic investigation of apomixis in Boechera (Brassicaceae).

Journal Article The New phytologist · January 2006 Understanding apomixis (asexual reproduction through seeds) is of great interest to both plant breeders and evolutionary biologists. The genus Boechera is an excellent system for studying apomixis because of its close relationship to Arabidopsis, the occur ... Full text Cite

Sexual reproduction, hybridization, apomixis, and polyploidization in the genus Boechera (Brassicaceae).

Journal Article American journal of botany · November 2005 Of the 340 genera in the Brassicaceae, apomictic reproduction is found only in the North American genus Boechera. We investigated phylogenetic relationships, ability to hybridize, mating system, and ploidy levels of 92 lines sampled from 85 populations and ... Full text Cite

The glucosinolate-myrosinase system in an ecological and evolutionary context.

Journal Article Current opinion in plant biology · June 2005 Functional analysis of natural variation in the model species Arabidopsis thaliana has enabled the cloning of many glucosinolate biosynthesis and hydrolysis genes. Variation in these genes is central to understanding the ecological role of the glucosinolat ... Full text Cite

Geographic and evolutionary diversification of glucosinolates among near relatives of Arabidopsis thaliana (Brassicaceae).

Journal Article Phytochemistry · June 2005 Glucosinolates are biologically active secondary metabolites that display both intra- and interspecific variation in the order Brassicales. Glucosinolate profiles have not been interpreted within a phylogenic framework and little is known regarding the pro ... Full text Cite

Epistasis and balanced polymorphism influencing complex trait variation.

Journal Article Nature · May 2005 Complex traits such as human disease, growth rate, or crop yield are polygenic, or determined by the contributions from numerous genes in a quantitative manner. Although progress has been made in identifying major quantitative trait loci (QTL), experimenta ... Full text Cite

Evolution of the trnF(GAA) gene in Arabidopsis relatives and the brassicaceae family: monophyletic origin and subsequent diversification of a plastidic pseudogene.

Journal Article Molecular biology and evolution · April 2005 Recently, we used the 5'-trnL(UAA)-trnF(GAA) region of the chloroplast DNA for phylogeographic reconstructions and phylogenetic analysis among the genera Arabidopsis, Boechera, Rorippa, Nasturtium, and Cardamine. Despite the fact that extensive gene duplic ... Full text Cite

A multilocus sequence survey in Arabidopsis thaliana reveals a genome-wide departure from a neutral model of DNA sequence polymorphism.

Journal Article Genetics · March 2005 The simultaneous analysis of multiple genomic loci is a powerful approach to studying the effects of population history and natural selection on patterns of genetic variation of a species. By surveying nucleotide sequence polymorphism at 334 randomly distr ... Full text Cite

Allele-specific assay reveals functional variation in the chalcone synthase promoter of Arabidopsis thaliana that is compatible with neutral evolution.

Journal Article The Plant cell · March 2005 Promoters are thought to play a major role in adaptive evolution, yet little is known about the regulatory diversity within species, where microevolutionary processes take place. To investigate the potential for evolutionary change in the promoter of a gen ... Full text Cite

Biogeographic distribution of polyploidy and B chromosomes in the apomictic Boechera holboellii complex.

Journal Article Cytogenetic and genome research · January 2005 The Boechera holboellii complex comprises B. holboellii and B. drummondii, both of which can reproduce through sex or apomixis. Sexuality is associated with diploid individuals, whereas apomictic individuals are diploid or triploid and may additionally hav ... Full text Cite

Nucleotide variation at the myrosinase-encoding locus, TGG1, and quantitative myrosinase enzyme activity variation in Arabidopsis thaliana.

Journal Article Molecular ecology · January 2005 The Arabidopsis thaliana TGG1 gene encodes thioglucoside glucohydrolase (myrosinase), an enzyme catalysing the hydrolysis of glucosinolate compounds. The enzyme is involved in plant defence against some insect herbivores, and is present in species of the o ... Full text Cite

Intraspecific diversification in North American Boechera stricta (= Arabis drummondii), Boechera xdivaricarpa, and Boechera holboellii (Brassicaceae) inferred from nuclear and chloroplast molecular markers--an integrative approach.

Journal Article American journal of botany · December 2004 We performed a combined evolutionary analysis of North American Boechera stricta, Boechera holboellii, and their hybrid Boechera ×divaricarpa using information on ploidy level estimators, allelic microsatellite variation, noncoding regions of the plastidic ... Full text Cite

Comparing the linkage maps of the close relatives Arabidopsis lyrata and A. thaliana.

Journal Article Genetics · November 2004 We have constructed a genetic map of Arabidopsis lyrata, a self-incompatible relative of the plant model species A. thaliana. A. lyrata is a diploid (n = 8) species that diverged from A. thaliana (n = 5) approximately 5 MYA. Mapping was conducted in a full ... Full text Cite

Successful herbivore attack due to metabolic diversion of a plant chemical defense.

Conference Proceedings of the National Academy of Sciences of the United States of America · April 2004 Plants protect themselves against herbivory with a diverse array of repellent or toxic secondary metabolites. However, many herbivorous insects have developed counteradaptations that enable them to feed on chemically defended plants without apparent negati ... Full text Cite

Rapid evolution of a pollen-specific oleosin-like gene family from Arabidopsis thaliana and closely related species.

Journal Article Molecular biology and evolution · April 2004 It has been shown in a variety of species that genes expressed in reproductive tissues evolve rapidly, which often appears to be the result of positive Darwinian selection. We investigated the evolution of a family of seven pollen-specific oleosin-like pro ... Full text Cite

Functional divergence in tandemly duplicated Arabidopsis thaliana trypsin inhibitor genes.

Journal Article Genetics · March 2004 In multigene families, variation among loci and alleles can contribute to trait evolution. We explored patterns of functional and genetic variation in six duplicated Arabidopsis thaliana trypsin inhibitor (ATTI) loci. We demonstrate significant variation i ... Full text Cite

Extensive chloroplast haplotype variation indicates Pleistocene hybridization and radiation of North American Arabis drummondii, A. x divaricarpa, and A. holboellii (Brassicaceae).

Journal Article Molecular ecology · February 2004 Arabis drummondii, A. holboellii and their hybrid A. x divaricarpa are widespread perennials of open habitats in North America. A phylogenetic analysis based on noncoding chloroplast DNA sequences (trnL intron and trnL/F intergenic spacer) resolved A. drum ... Full text Cite

Is the aneuploid chromosome in an apomictic Boechera holboellii a genuine B chromosome?

Journal Article Cytogenetic and genome research · January 2004 The Boechera holboellii complex comprises B. holboellii and B. drummondii, both of which can reproduce through sex or apomixis. Sexuality is associated with diploidy, whereas apomictic individuals can either be diploid, aneuploid or triploid. Aneuploid ind ... Full text Cite

Multilocus analysis of variation and speciation in the closely related species Arabidopsis halleri and A. lyrata.

Journal Article Genetics · January 2004 Nucleotide variation in eight effectively unlinked genes was surveyed in species-wide samples of the closely related outbreeding species Arabidopsis halleri and A. lyrata ssp. petraea and in three of these genes in A. lyrata ssp. lyrata and A. thaliana. Si ... Full text Cite

ECOLOGICAL GENOMICS OF GLUCOSINOLATES IN RELATIVES OF ARABIDOPSIS

Journal Article ACTA PHYSIOLOGIAE PLANTARUM · January 1, 2004 Link to item Cite

Evolutionary dynamics of an Arabidopsis insect resistance quantitative trait locus.

Conference Proceedings of the National Academy of Sciences of the United States of America · November 2003 Glucosinolate profiles differ among Arabidopsis thaliana ecotypes, caused by the composition of alleles at several glucosinolate biosynthetic loci. One of these, GS-Elong, harbors a family of methylthioalkylmalate synthase (MAM) genes that determine the si ... Full text Cite

Establishment of a high-efficiency SNP-based framework marker set for Arabidopsis.

Journal Article The Plant journal : for cell and molecular biology · October 2003 The major goal of this project was the establishment of a tool for rapid mapping of new mutations and genotyping in Arabidopsis consisting of at least 100 evenly spaced framework markers. We assembled a single nucleotide polymorphism (SNP)-based marker set ... Full text Cite

Evolution of plant resistance at the molecular level: ecological context of species interactions.

Journal Article Heredity · October 2003 Molecular data regarding the diversity of plant loci involved in resistance to herbivores or pathogens are becoming increasingly available. These genes demonstrate variable patterns of diversity, suggesting that they differ in their evolutionary history. I ... Full text Cite

Evolutionary and ecological functional genomics.

Journal Article Nature reviews. Genetics · August 2003 A unique combination of disciplines is emerging--evolutionary and ecological functional genomics--which focuses on the genes that affect ecological success and evolutionary fitness in natural environments and populations. Already this approach has provided ... Full text Cite

Large-scale identification and analysis of genome-wide single-nucleotide polymorphisms for mapping in Arabidopsis thaliana.

Journal Article Genome research · June 2003 Genetic markers such as single nucleotide polymorphisms (SNPs) are essential tools for positional cloning, association, or quantitative trait locus mapping and the determination of genetic relationships between individuals. We identified and characterized ... Full text Cite

Genetics of drought adaptation in Arabidopsis thaliana: I. Pleiotropy contributes to genetic correlations among ecological traits.

Journal Article Molecular ecology · May 2003 We examined patterns of genetic variance and covariance in two traits (i) carbon stable isotope ratio delta13C (dehydration avoidance) and (ii) time to flowering (drought escape), both of which are putative adaptations to local water availability. Greenhou ... Full text Cite

Population genetics of tandem trypsin inhibitor genes in Arabidopsis species with contrasting ecology and life history.

Journal Article Molecular ecology · May 2003 Duplicated genes are important in the evolution and ecology of plant-defences because herbivore and pathogen attack can be countered via functional diversification at two levels: among duplicated loci and within loci. We explore molecular sequence variatio ... Full text Cite

Multiple hybrid formation in natural populations: concerted evolution of the internal transcribed spacer of nuclear ribosomal DNA (ITS) in North American Arabis divaricarpa (Brassicaceae).

Journal Article Molecular biology and evolution · March 2003 DNA sequence variation of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA from Arabis holboellii, A. drummondii, and its putative hybrid A. divaricarpa was analyzed to study hybrid speciation in a species system geographically coverin ... Full text Cite

Applications of SNPs in ecology, evolution, and conservation

Journal Article Trends in Ecology and Evolution · 2003 Cite

Primers for 22 candidate genes for ecological adaptations in Brassicaceae

Journal Article Molecular Ecology Notes · September 1, 2002 There is an increasing interest in direct screening of polymorphisms at candidate loci to associate them with adaptations in natural situations. We report primers that amplify regions at 22 putatively orthologous functional loci in the family Brassicaceae: ... Full text Cite

Disarming the mustard oil bomb.

Conference Proceedings of the National Academy of Sciences of the United States of America · August 2002 Plants are attacked by a broad array of herbivores and pathogens. In response, plants deploy an arsenal of defensive traits. In Brassicaceae, the glucosinolate-myrosinase complex is a sophisticated two-component system to ward off opponents. However, this ... Full text Cite

Genetic architecture of plastic methyl jasmonate responses in Arabidopsis thaliana.

Journal Article Genetics · August 2002 The ability of a single genotype to generate different phenotypes in disparate environments is termed phenotypic plasticity, which reflects the interaction of genotype and environment on developmental processes. However, there is controversy over the defin ... Full text Cite

Recombination and gene conversion in a 170-kb genomic region of Arabidopsis thaliana.

Journal Article Genetics · July 2002 Arabidopsis thaliana is a highly selfing plant that nevertheless appears to undergo substantial recombination. To reconcile its selfing habit with the observations of recombination, we have sampled the genetic diversity of A. thaliana at 14 loci of approxi ... Full text Cite

Evolution. Chaperones as buffering agents?

Journal Article Science (New York, N.Y.) · June 2002 Full text Cite

Comparative analysis of quantitative trait loci controlling glucosinolates, myrosinase and insect resistance in Arabidopsis thaliana.

Journal Article Genetics · May 2002 Evolutionary interactions among insect herbivores and plant chemical defenses have generated systems where plant compounds have opposing fitness consequences for host plants, depending on attack by various insect herbivores. This interplay complicates unde ... Full text Cite

Benzoic acid glucosinolate esters and other glucosinolates from Arabidopsis thaliana.

Journal Article Phytochemistry · March 2002 The spectacular recent progress in Arabidopsis thaliana molecular genetics furnishes outstanding tools for studying the formation and function of all metabolites in this cruciferous species. One of the major groups of secondary metabolites in A. thaliana i ... Full text Cite

Cross-species microsatellite markers for elucidating population genetic structure in Arabidopsis and Arabis (Brassicaeae).

Journal Article Molecular ecology · March 2002 Species closely related to model organisms present the opportunity to efficiently apply molecular and functional tools developed by a large research community to taxa with different ecological and evolutionary histories. We complied 42 microsatellite loci ... Full text Cite

Plant evolutionary genomics.

Journal Article Current opinion in plant biology · February 2002 Evolutionary genomics combines functional and evolutionary analyses of genome conservation and differentiation. Gene duplication and polyploidy have fundamentally shaped the genomes of Arabidopsis and all angiosperms. Recent comparative studies have focuss ... Full text Cite

Evidence for regulation of resistance in Arabidopsis to Egyptian cotton worm by salicylic and jasmonic acid signaling pathways.

Journal Article Planta · February 2002 Signaling cross-talk between wound- and pathogen-response pathways influences resistance of plants to insects and disease. To elucidate potential interactions between salicylic acid (SA) and jasmonic acid (JA) defense pathways, we exploited the availabilit ... Full text Cite

Cost of defense in the context of plant competition: brassica rapa may grow and defend

Journal Article Ecology. · February 2002 Theory on costs of plant defense against herbivory in stressful environments predicts that costs should increase when competition is intense. This amplifies a fundamental dilemma that plants are thought to face: allocate limited resources to grow fast enou ... Full text Cite

Local and differential control of vegetative storage protein expression in response to herbivore damage in Arabidopsis thaliana.

Journal Article Physiologia plantarum · January 2002 Vegetative storage proteins (VSPs) are thought to fulfil important nutritional roles during plant development and stress adaptation. Plant responses to mechanical wounding and herbivore damage include an activation of VSP expression. It was recently sugges ... Full text Cite

Arabidopsis thaliana and its wild relatives: A model system for ecology and evolution

Journal Article Trends in Ecology and Evolution · December 1, 2001 The postgenomics era will bring many changes to ecology and evolution. Information about genomic sequence and function provides a new foundation for organismal biology. The crucifer Arabidopsis thaliana and its wild relatives will play an important role in ... Full text Cite

The Arabidopsis epithiospecifier protein promotes the hydrolysis of glucosinolates to nitriles and influences Trichoplusia ni herbivory.

Journal Article The Plant cell · December 2001 Glucosinolates are anionic thioglucosides that have become one of the most frequently studied groups of defensive metabolites in plants. When tissue damage occurs, the thioglucoside linkage is hydrolyzed by enzymes known as myrosinases, resulting in the fo ... Full text Cite

A gene controlling variation in Arabidopsis glucosinolate composition is part of the methionine chain elongation pathway.

Journal Article Plant physiology · November 2001 Arabidopsis and other Brassicaceae produce an enormous diversity of aliphatic glucosinolates, a group of methionine (Met)-derived plant secondary compounds containing a beta-thio-glucose moiety, a sulfonated oxime, and a variable side chain. We fine-scale ... Full text Cite

Comparative genomics and regulatory evolution: conservation and function of the Chs and Apetala3 promoters.

Journal Article Molecular biology and evolution · October 2001 DNA sequence variations of chalcone synthase (Chs) and Apetala3 gene promoters from 22 cruciferous plant species were analyzed to identify putative conserved regulatory elements. Our comparative approach confirmed the existence of numerous conserved sequen ... Full text Cite

Comparative quantitative trait loci mapping of aliphatic, indolic and benzylic glucosinolate production in Arabidopsis thaliana leaves and seeds.

Journal Article Genetics · September 2001 Secondary metabolites are a diverse set of plant compounds believed to have numerous functions in plant-environment interactions. Despite this importance, little is known about the regulation of secondary metabolite accumulation. We are studying the regula ... Full text Cite

SGP-1: prediction and validation of homologous genes based on sequence alignments.

Journal Article Genome research · September 2001 Conventional methods of gene prediction rely on the recognition of DNA-sequence signals, the coding potential or the comparison of a genomic sequence with a cDNA, EST, or protein database. Reasons for limited accuracy in many circumstances are species-spec ... Full text Cite

Local adaptation across a climatic gradient despite small effective population size in the rare sapphire rockcress.

Conference Proceedings. Biological sciences · August 2001 When assigning conservation priorities in endangered species, two common management strategies seek to protect remnant populations that (i) are the most genetically divergent or (ii) possess the highest diversity at neutral genetic markers. These two appro ... Full text Cite

Recurrent polyploid origins and chloroplast phylogeography in the Arabis holboellii complex (Brassicaceae).

Journal Article Heredity · July 2001 Arabis holboellii is a North American member of the Brassicaceae that can reproduce via sex or apomixis. Previous studies have shown sexual individuals to be diploid, whilst apomictic individuals can be diploid (and aneuploid) or polyploid (typically 3x). ... Full text Cite

Genetic control of natural variation in Arabidopsis glucosinolate accumulation.

Journal Article Plant physiology · June 2001 Glucosinolates are biologically active secondary metabolites of the Brassicaceae and related plant families that influence plant/insect interactions. Specific glucosinolates can act as feeding deterrents or stimulants, depending upon the insect species. He ... Full text Cite

Molecular systematics of the Brassicaceae: evidence from coding plastidic matK and nuclear Chs sequences.

Journal Article American journal of botany · March 2001 Phylogenetic relationships were inferred using nucleotide sequence variation of the nuclear-encoded chalcone synthase gene (Chs) and the chloroplast gene matK for members of five tribes from the family Brassicaceae to analyze tribal and subtribal structure ... Full text Cite

Gene duplication in the diversification of secondary metabolism: tandem 2-oxoglutarate-dependent dioxygenases control glucosinolate biosynthesis in Arabidopsis.

Journal Article The Plant cell · March 2001 Secondary metabolites are a diverse set of plant compounds believed to have numerous functions in plant-environment interactions. The large chemical diversity of secondary metabolites undoubtedly arises from an equally diverse set of enzymes responsible fo ... Full text Cite

Genetic isolation by distance in Arabidopsis thaliana: biogeography and postglacial colonization of Europe.

Journal Article Molecular ecology · December 2000 Arabidopsis thaliana provides a useful model system for functional, evolutionary and ecological studies in plant biology. We have analysed natural genetic variation in A. thaliana in order to infer its biogeographical and historical distribution across Eur ... Full text Cite

Induced plant defense responses against chewing insects. Ethylene signaling reduces resistance of Arabidopsis against Egyptian cotton worm but not diamondback moth.

Journal Article Plant physiology · November 2000 The induction of plant defenses by insect feeding is regulated via multiple signaling cascades. One of them, ethylene signaling, increases susceptibility of Arabidopsis to the generalist herbivore Egyptian cotton worm (Spodoptera littoralis; Lepidoptera: N ... Full text Cite

Comparative evolutionary analysis of chalcone synthase and alcohol dehydrogenase loci in Arabidopsis, Arabis, and related genera (Brassicaceae).

Journal Article Molecular biology and evolution · October 2000 We analyzed sequence variation for chalcone synthase (Chs) and alcohol dehydrogenase (Adh) loci in 28 species in the genera Arabidopsis and Arabis and related taxa from tribe Arabideae. Chs was single-copy in nearly all taxa examined, while Adh duplication ... Full text Cite

Biotic interactions. Genomics and coevolution.

Journal Article Current opinion in plant biology · August 2000 Full text Cite

alpha-Keto acid elongation and glucosinolate biosynthesis in Arabidopsis thaliana.

Journal Article TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik · August 2000 QTL mapping of glucosinolates in a RI population derived from an F1 hybrid between the Arabidopsis thaliana ecotypes Columbia and Landsberg erecta identified a single major QTL coincident with the GSL-ELONG locus which regulates side chain elongation. Phys ... Full text Cite

Rapid evolution in plant chitinases: molecular targets of selection in plant-pathogen coevolution.

Conference Proceedings of the National Academy of Sciences of the United States of America · May 2000 Many pathogen recognition genes, such as plant R-genes, undergo rapid adaptive evolution, providing evidence that these genes play a critical role in plant-pathogen coevolution. Surprisingly, whether rapid adaptive evolution also occurs in genes encoding o ... Full text Cite

Editorial Overview: Genomics and coevolution

Journal Article Current Opinion in Plant Biology · 2000 Cite

Systematic genetic and molecular analysis of insect resistance in Arabidopsis

Conference BIOLOGY OF PLANT-MICROBE INTERACTIONS, VOL 2 · January 1, 2000 Link to item Cite

Ecological costs of plant resistance to herbivores in the currency of pollination.

Journal Article Evolution; international journal of organic evolution · August 1999 Full text Cite

Plant-insect interactions.

Journal Article Current opinion in plant biology · August 1999 Recent research shows partially overlapping signal transduction pathways controlling responses to wounding, insects, and pathogens. Chemical and behavioral assays show that plants release herbivore-specific volatiles, and that parasitic wasps can distingui ... Full text Cite

Ecological costs of plant resistance to herbivores in the currency of pollination

Journal Article Evolution · 1999 In this paper, we examine how ecological costs of resistance might be manifested through plant relationships with pollinators. If defensive compounds are incorporated into floral structures or if they are sufficiently costly that fewer rewards are offered ... Cite

Genetics and evolution of insect resistance in Arabidopsis.

Conference Insect-Plant Interactions and Inducible Plant Defense · 1999 The genetic and molecular tools available in Arabidopsis allow identification of insect resistance genes. Many functional aspects of pest recognition and signal transduction are conserved in the defensive physiology of a broad range of plant species. There ... Link to item Cite

A polymerase chain reaction method for detecting dwarf mistletoe infection in douglas-fir and western larch

Journal Article Canadian Journal of Forest Research · January 1, 1999 Early detection and management of dwarf mistletoe (Arceuthobium spp.) is currently limited by the inability to rapidly detect infection during the 2- to 5-year endophyte phase of the parasite. We describe a polymerase chain reaction (PCR) technique for det ... Full text Cite

Molecular systematics and evolution of Arabidopsis and Arabis

Journal Article Plant Biology · January 1, 1999 We provide a phylogenetic analysis of the genera Arabidopsis and Arabis based on nuclear ribosomal DNA sequences. We show that traditional taxonomical concepts within tribe Arabideae, which includes these genera, are highly artificial. Arabis and Arabidops ... Full text Cite

Chemical ecology in the molecular era

Journal Article Trends in Plant Science · September 1, 1998 Full text Cite

The molecular basis of quantitative genetic variation in central and secondary metabolism in Arabidopsis.

Journal Article Genetics · June 1998 To find the genes controlling quantitative variation, we need model systems where functional information on physiology, development, and gene regulation can guide evolutionary inferences. We mapped quantitative trait loci (QTLs) influencing quantitative le ... Full text Cite

Evolution of pest-induced defenses in Brassica plants: Tests of theory

Journal Article Ecology · January 1, 1998 Theory on the evolution of pest-induced defenses in plants predicts (1) a negative genetic correlation between induced and constitutive (basal) levels of secondary metabolites, and (2) costs of maintaining high constitutive levels of secondary metabolites. ... Full text Cite

Species-specific response of glucosinolate content to elevated atmospheric CO2

Journal Article Journal of Chemical Ecology · January 1, 1997 The carbon/nutrient balance hypothesis has recently been interpreted to predict that plants grown under elevated CO2 environments will allocate excess carbon to defense, resulting in an increase in carbon-based secondary compounds. A related pre ... Full text Cite

Pleiotropy causes long-term genetic constraints on life-history evolution in Brassica rapa.

Journal Article Evolution; international journal of organic evolution · October 1996 Full text Cite

Genetics of Brassica rapa. 3. Costs of disease resistance to three fungal pathogens.

Journal Article Evolution; international journal of organic evolution · October 1996 Full text Cite

Genetics of Brassica rapa. 3. Costs of disease resistance to three fungal pathogens

Journal Article Evolution · 1996 Genetic costs of resistance to pathogens may be an important factor maintaining heritable variation for resistance in natural populations. Pleiotropic fitness trade-offs occur when genetic resistance causes reduction in other components of illness. Althoug ... Cite

Pleiotropy causes long-term genetic constraints on life-history evolution in Brassica rapa

Journal Article Evolution · 1996 Fundamental, long-term genetic trade-offs constrain life-history evolution in wild crucifer populations. I studied patterns of genetic constraint in Brassica rapa by estimating genetic correlations among life- history components by quantitative genetic ana ... Cite

Genetic constraints on life-history evolution: Quantitative-trait loci influencing growth and flowering in Arabidopsis thaliana

Journal Article Evolution · 1996 We have mapped genes causing life-history trade-offs, and they behave as predicted by ecological theory. Energetic and quantitative-genetic models suggest a trade-off between age and size at first reproduction. Natural selection favored plants that flower ... Cite

Glucosinolates and Herbivory by Specialists (Coleoptera: Chrysomelidae, Lepidoptera: Plutellidae): Consequences of Concentration and Induced Resistance

Journal Article Environmental Entomology · January 1, 1996 Varied responses by specialist herbivores to glucosinolates could be a function of glucosinolate concentration or other correlated resistance factors. Herbivory by the specialist flea beetle Phyllotreta cruciferae (Goeze), and diamondback moth, Plutella xy ... Full text Cite

Physiology and costs of resistance to herbivory and disease in Brassica

Journal Article Entomologia Experimentalis Et Applicata · January 1, 1996 We used artificial selection experiments to study genetic allocation costs and physiological mechanisms of resistance to herbivory and fungal disease. Genetic costs to resistance were present in some instances and absent in others. Genetic resistance to th ... Full text Cite

Genetics of Brassica rapa (syn. campestris). 2. Multiple disease resistance to three fungal pathogens: Peronospora parasitica, Albugo candida and Leptosphaeria maculans.

Journal Article Heredity · October 1995 Although the genetic basis of multiple disease resistance (MDR) is poorly understood, it is of great value for understanding the evolution of disease resistance in natural plant populations and for increasing crop yields in agriculture. In Brassica rapa, w ... Full text Cite

Erratum: ANOVA for Unbalanced Data: An Overview

Journal Article Ecology · September 1995 Full text Cite

The molecular basis of quantitative genetic variation in natural populations.

Journal Article Trends in ecology & evolution · August 1995 DNA markers allow us to study quantitative trait loci (QTL) - the genes that control adaptation and quantitative variation. Experiments can map the genes responsible for quantitative variation and address the evolutionary and ecological significance of thi ... Full text Cite

Interval mapping of viability loci causing heterosis in Arabidopsis.

Journal Article Genetics · July 1995 The genetic basis of heterosis has implications for many problems in genetics and evolution. Heterosis and inbreeding depression affect human genetic diseases, maintenance of genetic variation, evolution of breeding systems, agricultural productivity, and ... Full text Cite

Seed predation, pathogen infection and life-history traits in Brassica rapa.

Journal Article Oecologia · June 1995 Herbivory and disease can shape the evolution of plant populations, but their joint effects are rarely investigated. Families of plants of Brassica rapa (Brassicaceae) were grown from seeds collected in two naturalized populations in an experimental garden ... Full text Cite

Identification of quantitative trait loci influencing wood specific gravity in an outbred pedigree of loblolly pine.

Journal Article Genetics · December 1994 We report the identification of quantitative trait loci (QTL) influencing wood specific gravity (WSG) in an outbred pedigree of loblolly pine (Pinus taeda L.). QTL mapping in an outcrossing species is complicated by the presence of multiple alleles (> 2) a ... Full text Cite

Effects of serial inbreeding on fitness components in Impatiens capensis.

Journal Article Evolution; international journal of organic evolution · June 1994 Full text Cite

EFFECTS OF SERIAL INBREEDING ON FITNESS COMPONENTS IN IMPATIENS CAPENSIS.

Journal Article Evolution; international journal of organic evolution · June 1994 Studies of inbreeding depression in wild plants customarily compare the fitness of outcrossed progeny to progeny derived from one generation of self-pollination. We compare levels of inbreeding depression in a greenhouse in two populations of jewelweed usi ... Full text Cite

Arabidopsis cDNA sequence encoding myrosinase.

Journal Article Plant physiology · October 1993 Full text Cite

Sequence of a Brassica campestris myrosinase gene.

Journal Article Plant physiology · August 1993 Full text Cite

ANOVA for unbalanced data: an overview

Journal Article Ecology · January 1, 1993 When the response variables have continuous distributions and the conditions are discrete, whether inherently or by design, then it is appropriate to analyze the data using analysis of variance (ANOVA). When data conform to a complete, balanced design (equ ... Full text Cite

Does environmental variation maintain genetic variation? A question of scale.

Journal Article Trends in ecology & evolution · December 1992 Full text Cite

Genetic diversity in plant species in Glacier National Park

Journal Article Northwest Environmental Journal · 1992 Cite

Management of Arabis fecunda, a threatened plant

Journal Article Northwest Environmental Journal · 1992 Cite

Genetics of Brassica campestris. 1. Genetic constraints on evolution of life-history characters.

Journal Article Evolution; international journal of organic evolution · March 1991 Full text Cite

GENETICS OF BRASSICA CAMPESTRIS. 1. GENETIC CONSTRAINTS ON EVOLUTION OF LIFE-HISTORY CHARACTERS.

Journal Article Evolution; international journal of organic evolution · March 1991 Energy allocation arguments suggest a possible tradeoff between timing and magnitude of reproduction: plants that postpone reproduction may accumulate greater resources and consequently produce more offspring. However, early reproduction may be favored whe ... Full text Cite

Quantitative genetic changes in small populations

Conference Proceedings of the Fourth International Congress of Systematic and Evolutionary Biology · 1991 Cite

Distance between mates affects seedling characters in a population of Impatiens capensis (Balsaminaceae)

Journal Article American Journal of Botany · January 1, 1991 Tested for the presence of an optimal outcrossing distance in a population of Impatiens capensis, an annual herb that possesses a mixed mating system, by measuring fitness components for offspring of parents that were separated by distances of 2, 20 or 50 ... Full text Cite

Comments on the Causes of Natural Selection

Journal Article Evolution · December 1990 Full text Cite

Statistical genetics of an annual plant, Impatiens capensis. I. Genetic basis of quantitative variation.

Journal Article Genetics · February 1990 Analysis of quantitative genetics in natural populations has been hindered by computational and methodological problems in statistical analysis. We developed and validated a jackknife procedure to test for existence of broad sense heritabilities and domina ... Full text Cite

Statistical genetics of an annual plant, Impatiens capensis. II. Natural selection.

Journal Article Genetics · February 1990 Measurement of natural selection on correlated characters provides valuable information on fitness surfaces, patterns of directional, stabilizing, or disruptive selection, mechanisms of fitness variation operating in nature, and possible spatial variation ... Cite

Comments on the causes of natural selection

Journal Article Evolution · 1990 Cite

FITNESS CONSEQUENCES OF OUTCROSSING IN IMPATIENS CAPENSIS: TESTS OF THE FREQUENCY-DEPENDENT AND SIB-COMPETITION MODELS.

Journal Article Evolution; international journal of organic evolution · August 1989 Using field and greenhouse experiments, we tested two hypotheses that could account for the maintenance of outcrossing in Impatiens capensis. Seedlings derived from cleistogamous (CL) and chasmogamous (CH) flowers were grown under competitive conditions wh ... Full text Cite

REGRESSION ANALYSIS OF NATURAL SELECTION: STATISTICAL INFERENCE AND BIOLOGICAL INTERPRETATION.

Journal Article Evolution; international journal of organic evolution · November 1987 Recent theoretical work in quantitative genetics has fueled interest in measuring natural selection in the wild. We discuss statistical and biological issues that may arise in applications of Lande and Arnold's (1983) multiple-regression approach to measur ... Full text Cite

Analysis of local variation in plant size.

Journal Article Ecology · January 1, 1987 Attempts to quantify local competitive interactions by examining size and growth of neighboring plants may suffer from several statistical difficulties: 1) when individuals are analyzed both as focal plants and as neighbors of other individuals, observatio ... Full text Cite

Genetic load and heterozygosity in the Pinaceae

Journal Article Can. J. Genet. Cytol. · 1986 Cite

A note on sex and life histories

Journal Article American Naturalist · 1981 Cite