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

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.
Authors:
;  [1] ; ; ;  [2] ;  [3]
  1. (Geological Survey, Seattle, WA (United States) Univ. of Washington, Seattle, WA (United States). Dept. of Botany)
  2. (Geological Survey, Seattle, WA (United States))
  3. (Volcani Center, Bet Dagan (Israel). Dept. of Plant Pathology)
Publication Date:
OSTI Identifier:
6279795
Resource Type:
Journal Article
Resource Relation:
Journal Name: Plant Physiology; (Bethesda); Journal Volume: 119:2
Sponsoring Org:
NSF; DOE; DOA; National Science Foundation, Washington, DC (United States); USDOE, Washington, DC (United States); Department of Agriculture, Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; CROPS; CUCUMBERS; DISEASE RESISTANCE; FUNGI; MATHEMATICAL MODELS; PLANT DISEASES; FOOD; MAGNOLIOPHYTA; MAGNOLIOPSIDA; PLANTS; VEGETABLES 553000* -- Agriculture & Food Technology