Home About us MoEF Contact us Sitemap Tamil Website  
About Envis
Whats New
Microorganisms
Research on Microbes
Database
Bibliography
Publications
Library
E-Resources
Microbiology Experts
Events
Online Submission
Access Statistics

Site Visitors

blog tracking


 
The Plant Cell
Vol. 19, No. , 2007; Pages:
1665–1681

ABA Is an Essential Signal for Plant Resistance to Pathogens Affecting JA Biosynthesis and the Activation of Defenses in Arabidopsis W

Bruce A.T. Adie,a Julian Perez-Perez,a Manuel M. Perez-Perez,a Marta Godoy,a Jose-J. Sanchez-Serrano,a Eric A. Schmelz,b and Roberto Solanoa,1

Departamento de Genetica Molecular de Plantas, Centro Nacional de Biotecnologia–Consejo Superior de Investigaciones Cientificas, Campus Universidad Auto´ noma, 28049 Madrid, Spain.


Abstract

Analyses of Arabidopsis thaliana defense response to the damping-off oomycete pathogen Pythium irregulare show that resistance to P. irregulare requires a multicomponent defense strategy. Penetration represents a first layer, as indicated by the susceptibility of pen2 mutants, followed by recognition, likely mediated by ERECTA receptor-like kinases. Subsequent signaling of inducible defenses is predominantly mediated by jasmonic acid (JA), with insensitive coi1 mutants showing extreme susceptibility. In contrast with the generally accepted roles of ethylene and salicylic acid cooperating with or antagonizing, respectively, JA in the activation of defenses against necrotrophs, both are required to prevent disease progression, although much less so than JA. Meta-analysis of transcriptome profiles confirmed the predominant role of JA in activation of P. irregulare–induced defenses and uncovered abscisic acid (ABA) as an important regulator of defense gene expression. Analysis of cis-regulatory sequences also revealed an unexpected overrepresentation of ABA response elements in promoters of P. irregulare–responsive genes. Subsequent infections of ABA-related and callose-deficient mutants confirmed the importance of ABA in defense, acting partly through an undescribed mechanism. The results support a model for ABA affecting JA biosynthesis in the activation of defenses against this oomycete.

Keywords:Arabidopsis,Pythium irregulare,ERECTA,JA biosynthesis,pathogens.


Corresponding author: Phone:xxxxxxxxxxx Fax:34-91-5854506

E-mail: rsolano@cnb.uam.es

 

 
Copyright © 2005 ENVIS Centre ! All rights reserved
This site is optimized for 1024 x 768 screen resolution