BioControl (2014) 59, 437-448

Mee Kyung Sang and Ki Deok Kim (2014)
Biocontrol activity and root colonization by Pseudomonas corrugata strains CCR04 and CCR80 against Phytophthora blight of pepper
BioControl 59 (4), 437-448
Abstract: Previously, we selected Pseudomonas corrugata strains CCR04 and CCR80 as rhizobacteria suppressive to Phytophthora blight of pepper caused by Phytophthora capsici. In this study, we investigated soil microbial activity in pepper plants root-drenched with strains CCR04 and CCR80 in relation to their biocontrol activity, root colonization by using bacterial population counts and scanning electron microscopy, biofilm formation and cell motility as well as cell sensitivity to hydrogen peroxide (H₂O₂). As a result, strains CCR04 and CCR80 more effectively suppressed disease expression in pepper plants through root colonization than did Paenibacillus polymyxa AC-1 (positive control), Escherichia coli DH5a (negative control) or MgSO₄ solution (untreated control). Strains CCR04 and CCR80 had efficient biofilm formation and cell motility (swimming and swarming activities) abilities and responded to certain tested compounds (amino acids, organic acids and sugars), which can be found in root exudates. Strains CCR04 and CCR80 and the positive control strain AC-1 were relatively insensitive to H₂O₂, a reactive oxidative species at concentration up to 20 mM, unlike the negative control strain DH5a. Taken together, these results suggest that P. corrugata CCR04 and CCR80 can effectively inhibit P. capsici infection of pepper plants through successful colonization of plant roots. This bacterial colonization may be facilitated by the biofilm formation ability and cell motility in addition to reduced sensitivity to H₂O₂ and probably the production of antimicrobial compounds. These findings highlight the potential of strains CCR04 and CCR80 as biocontrol agents for the management of Phytophthora blight of pepper.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Ki Deok Kim

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Phytophthora capsici	Green pepper/chilli (Capsicum)
Pseudomonas corrugata (antagonist)	Phytophthora capsici	Green pepper/chilli (Capsicum)	Korea-South