Biocontrol activity and root colonization by Pseudomonas corrugata strains CCR04 and CCR80 against Phytophthora blight of pepper

Mee Kyung Sang, Ki Deok Kim

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17 Citations (Scopus)

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 DH5α (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 DH5α. 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.

Original languageEnglish
Pages (from-to)437-448
Number of pages12
JournalBioControl
Volume59
Issue number4
DOIs
Publication statusPublished - 2014 Jan 1

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ASJC Scopus subject areas

  • Insect Science
  • Agronomy and Crop Science

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