A Cluster of Mutations Disrupt the Avirulence but Not the Virulence Function of AvrPto

avrPto in Pseudomonas syringae pv. tomato encodes an avirulence protein that triggers race-specific resistance in tomato plants carrying Pto. The AvrPto protein is secreted from P. syringae pv. tomato to plant cells through the type III secretion pathway and activates race-specific resistance by a d...

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Bibliographic Details
Main Authors: Libo Shan, Ping He, Jian-Min Zhou, Xiaoyan Tang
Format: Article
Language:English
Published: The American Phytopathological Society 2000-06-01
Series:Molecular Plant-Microbe Interactions
Online Access:https://apsjournals.apsnet.org/doi/10.1094/MPMI.2000.13.6.592
Description
Summary:avrPto in Pseudomonas syringae pv. tomato encodes an avirulence protein that triggers race-specific resistance in tomato plants carrying Pto. The AvrPto protein is secreted from P. syringae pv. tomato to plant cells through the type III secretion pathway and activates race-specific resistance by a direct interaction with the Pto protein. Here we report that avrPto enhances the virulence of P. syringae pv. tomato in a strain-dependent manner in tomato plants lacking Pto. To determine whether the virulence function can be structurally separated from the avirulence function, we examined the virulence activity of a group of AvrPto mutants that carry single amino acid substitutions and lack the avirulence activity on tomato plants. Three mutants that were clustered in the center of AvrPto exhibited virulence activity in tomato plants with or without Pto. The rest of the mutations abolished the virulence. The identification of these mutants suggested that the aviru-lence function of AvrPto can be structurally separated from the virulence function.
ISSN:0894-0282
1943-7706