A Pseudomonas syringae type III effector suppresses cell wall-based extracellular defense in susceptible Arabidopsis plants.
Published
Journal Article
Bacterial effector proteins secreted through the type III secretion system (TTSS) play a crucial role in causing plant and human diseases. Although the ability of type III effectors to trigger defense responses in resistant plants is well understood, the disease-promoting functions of type III effectors in susceptible plants are largely enigmatic. Previous microscopic studies suggest that in susceptible plants the TTSS of plant-pathogenic bacteria transports suppressors of a cell wall-based plant defense activated by the TTSS-defective hrp mutant bacteria. However, the identity of such suppressors has remained elusive. We discovered that the Pseudomonas syringae TTSS down-regulated the expression of a set of Arabidopsis genes encoding putatively secreted cell wall and defense proteins in a salicylic acid-independent manner. Transgenic expression of AvrPto repressed a similar set of host genes, compromised defense-related callose deposition in the host cell wall, and permitted substantial multiplication of an hrp mutant. AvrPto is therefore one of the long postulated suppressors of an salicylic acid-independent, cell wall-based defense that is aimed at hrp mutant bacteria.
Full Text
Duke Authors
Cited Authors
- Hauck, P; Thilmony, R; He, SY
Published Date
- July 2003
Published In
Volume / Issue
- 100 / 14
Start / End Page
- 8577 - 8582
PubMed ID
- 12817082
Pubmed Central ID
- 12817082
Electronic International Standard Serial Number (EISSN)
- 1091-6490
International Standard Serial Number (ISSN)
- 0027-8424
Digital Object Identifier (DOI)
- 10.1073/pnas.1431173100
Language
- eng