L-Alanine augments rhizobacteria-induced systemic resistance in cucumber.
Bacillus vallismortis strain EXTN-1 is a proven biotic elicitor of systemic resistance in many crops against various pathogens. L: -Alanine (Ala) was tested in cucumber as a chemical elicitor of induced systemic resistance (ISR) against Colletotrichum orbiculare. In the greenhouse, both Ala and EXTN-1 induced significant levels of disease suppression in cucumber against anthracnose. When cucumber plants were treated with EXTN-1 and Ala together, augmentative disease suppression was observed. Experiments with transgenic tobacco plants carrying pathogenesis-related genes fused with the beta-glucuronidase (GUS) reported gene (PR-1a::GUS & PDF 1.2::GUS) showed an enhanced activation of both PR-1a and PDF 1.2 genes upon combined treatment with Ala and EXTN-1. RT-PCR analysis with transgenic (PR-1a or PDF 1.2 over expressing) Arabidopsis plant showed more enhanced expression of resistance genes PR-1a and PDF 1.2 upon combined treatment with Ala and EXTN-1 than either alone. An augmentative ISR effect, when the bacterial elicitor and chemical elicitor were combined together, was confirmed.
Park
K S
KS
Division of Agricultural Microbiology, National Academy of Agricultural Science, Suwon 441-707, Republic of Korea. kspark@rda.go.kr
Paul
D
D
Kim
J S
JS
Park
J W
JW
D000409:Alanine / Q000276:immunology / Q000494:pharmacology*; D001407:Bacillus / Q000502:physiology; D020231:Colletotrichum / Q000502:physiology; D018553:Cucumis sativus / Q000187:drug effects* / Q000276:immunology* / Q000382:microbiology; D007113:Immunity, Innate / Q000187:drug effects*; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D018517:Plant Roots / Q000187:drug effects / Q000276:immunology / Q000382:microbiology
D000409:Alanine