Biochemical analysis of plant protection afforded by a nonpathogenic endophytic mutant of Colletotrichum magna

Plant Physiology
By: , and 

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Abstract

A nonpathogenic mutant of Colletotrichum magna (path-1) was previously shown to protect watermelon (Citrullus lanatus) and cucumber (Cucumis sativus) seedlings from anthracnose disease elicited by wild-type C. magna. Disease protection was observed in stems of path-1-colonized cucurbits but not in cotyledons, indicating that path-1 conferred tissue-specific and/or localized protection. Plant biochemical indicators of a localized and systemic (peroxidase, phenylalanine ammonia-lyase, lignin, and salicylic acid) 'plant-defense' response were investigated in anthracnose-resistant and -susceptible cultivars of cucurbit seedlings exposed to four treatments: (1) water (control), (2) path-1 conidia, (3) wild-type conidia, and (4) challenge conditions (inoculation into path-1 conidia for 48 h and then exposure to wild-type conidia). Collectively, these analyses indicated that disease protection in path-1 colonized plants was correlated with the ability of these plants to mount a defense response more rapidly and to equal or greater levels than plants exposed to wild-type C. magna alone. Watermelon plants colonized with path-1 were also protected against disease caused by Colletotrichum orbiculare and Fusarium oxysporum. A model based on the kinetics of plant-defense activation is presented to explain the mechanism of path-1-conferred disease protection.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Biochemical analysis of plant protection afforded by a nonpathogenic endophytic mutant of Colletotrichum magna
Series title Plant Physiology
DOI 10.1104/pp.119.2.795
Volume 119
Issue 2
Year Published 1999
Language English
Publisher American Society of Plant Physiologists
Contributing office(s) Western Fisheries Research Center
Description 10 p.
First page 795
Last page 804