Open AccessThe antagonistic strain B acillus subtilis UMAF 6639 also confers protection to melon plants against cucurbit powdery mildew by activation of jasmonate‐ and salicylic acid‐dependent defence responses
Author(s) -
GarcíaGutiérrez Laura,
Zeriouh Houda,
Romero Diego,
Cubero Jaime,
Vicente Antonio,
PérezGarcía Alejandro
Publication year - 2013
Publication title -
microbial biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.287
H-Index - 74
ISSN - 1751-7915
DOI - 10.1111/1751-7915.12028
Subject(s) - powdery mildew , biology , blumeria graminis , salicylic acid , microbiology and biotechnology , biological pest control , jasmonate , systemic acquired resistance , lipopeptide , defence mechanisms , botany , plant disease resistance , biochemistry , bacteria , mutant , arabidopsis , gene , genetics
Summary Biological control of plant diseases has gained acceptance in recent years. B acillus subtilis UMAF 6639 is an antagonistic strain specifically selected for the efficient control of the cucurbit powdery mildew fungus P odosphaera fusca , which is a major threat to cucurbits worldwide. The antagonistic activity relies on the production of the antifungal compounds iturin and fengycin. In a previous study, we found that UMAF 6639 was able to induce systemic resistance ( ISR ) in melon and provide additional protection against powdery mildew. In the present work, we further investigated in detail this second mechanism of biocontrol by UMAF 6639. First, we examined the signalling pathways elicited by UMAF 6639 in melon plants, as well as the defence mechanisms activated in response to P . fusca . Second, we analysed the role of the lipopeptides produced by UMAF 6639 as potential determinants for ISR activation. Our results demonstrated that UMAF 6639 confers protection against cucurbit powdery mildew by activation of jasmonate‐ and salicylic acid‐dependent defence responses, which include the production of reactive oxygen species and cell wall reinforcement. We also showed that surfactin lipopeptide is a major determinant for stimulation of the immune response. These results reinforce the biotechnological potential of UMAF 6639 as a biological control agent.