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The Erwinia amylovora avrRpt2EA gene contributes to virulence on pear and AvrRpt2EA is recognized by Arabidopsis RPS2 when expressed in pseudomonas syringae.

Publication ,  Journal Article
Zhao, Y; He, S-Y; Sundin, GW
Published in: Molecular plant-microbe interactions : MPMI
June 2006

The enterobacterium Erwinia amylovora is a devastating plant pathogen causing necrotrophic fire blight disease of apple, pear, and other rosaceous plants. In an attempt to identify genes induced during infection of host plants, we identified and cloned a putative effector gene, avrRpt2EA. The deduced amino-acid sequence of the translated AvrRpt2EA protein is homologous to the effector protein AvrRpt2 previously reported in Pseudomonas syringae pv. tomato. These two proteins share 58% identity (70% similarity) in the functional domain; however, the secretion and translocation signal domain varied. The avrRpt2EA promoter region contains a typical 'hrp box,' which suggests that avrRpt2EA is regulated by the alternative sigma factor, HrpL. avrRpt2EA was detected in all E. amylovora strains tested but not in other closely related Erwinia species. An avrRpt2EA deletion mutant was reduced in its ability to cause systemic infection on immature pear fruits as compared with the wild-type strain, indicating that avrRpt2EA acts as a virulence factor on its native host. Growth of P. syringae pv. tomato DC3000 expressing avrRpt2EA was 10-fold higher than that of P. syringae pv. tomato DC3000 in an Arabidopsis rps2 mutant, indicating that avrRpt2EA promotes virulence of P. syringae pv. tomato DC3000 on Arabidopsis similar to P. syringae pv. tomato avrRpt2. When avrRpt2EA was expressed in P. syringae pv. tomato DC3000 in its native form, a weak hypersensitive response (HR) was induced in Arabidopsis; however, a hybrid protein containing the P. syringae pv. tomato avrRpt2 signal sequence, when expressed from the P syringae pv. tomato avrRpt2 promoter, caused a strong HR. Thus, the signal sequence and promoter of avrRpt2EA may affect its expression, secretion, or translocation, singly or in combination, in P. syringae pv. tomato DC3000. These results indicated that avrRpt2EA is genetically recognized by the RPS2 disease resistance gene in Arabidopsis when expressed in P. syringae pv. tomato DC3000. The results also suggested that although distinct pathogens such as E. amylovora and P. syringae may contain similar effector genes, expression and secretion of these effectors can be under specific regulation by the native pathogen.

Duke Scholars

Published In

Molecular plant-microbe interactions : MPMI

DOI

ISSN

0894-0282

Publication Date

June 2006

Volume

19

Issue

6

Start / End Page

644 / 654

Related Subject Headings

  • Sequence Alignment
  • Recombinant Fusion Proteins
  • Pyrus
  • Pseudomonas syringae
  • Promoter Regions, Genetic
  • Plant Leaves
  • Plant Biology & Botany
  • Mutation
  • Molecular Sequence Data
  • Erwinia amylovora
 

Citation

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Zhao, Y., He, S.-Y., & Sundin, G. W. (2006). The Erwinia amylovora avrRpt2EA gene contributes to virulence on pear and AvrRpt2EA is recognized by Arabidopsis RPS2 when expressed in pseudomonas syringae. Molecular Plant-Microbe Interactions : MPMI, 19(6), 644–654. https://doi.org/10.1094/mpmi-19-0644
Zhao, Youfu, Sheng-Yang He, and George W. Sundin. “The Erwinia amylovora avrRpt2EA gene contributes to virulence on pear and AvrRpt2EA is recognized by Arabidopsis RPS2 when expressed in pseudomonas syringae.Molecular Plant-Microbe Interactions : MPMI 19, no. 6 (June 2006): 644–54. https://doi.org/10.1094/mpmi-19-0644.
Zhao, Youfu, et al. “The Erwinia amylovora avrRpt2EA gene contributes to virulence on pear and AvrRpt2EA is recognized by Arabidopsis RPS2 when expressed in pseudomonas syringae.Molecular Plant-Microbe Interactions : MPMI, vol. 19, no. 6, June 2006, pp. 644–54. Epmc, doi:10.1094/mpmi-19-0644.

Published In

Molecular plant-microbe interactions : MPMI

DOI

ISSN

0894-0282

Publication Date

June 2006

Volume

19

Issue

6

Start / End Page

644 / 654

Related Subject Headings

  • Sequence Alignment
  • Recombinant Fusion Proteins
  • Pyrus
  • Pseudomonas syringae
  • Promoter Regions, Genetic
  • Plant Leaves
  • Plant Biology & Botany
  • Mutation
  • Molecular Sequence Data
  • Erwinia amylovora