Ethyl Acetate Extract of Bacillus pumilus SH122 Induces Resistance Against Phytophthora Blight in red pepper plant (Capsicum annuum) = Bacillus pumilus SH122의 에틸 아세테이트 추출물에 의한 고추역병의 저항성 유도

다국어 초록 (Multilingual Abstract)

In order to obtain bacterial metabolite inducing disease resistance in plants, bacteria were isolated from plant root and rhizosphere, and then ethyl acetate extract of each bacterial culture was used to screening for induction of resistance against phytophthora blight of red pepper plant. Among 200 bacterial isolates tested, isolate SH122 induced resistance consistently and significantly. Disease severity and lesion length of phytophthora blight on SH122 extract treated-pepper plants were 20% and 21% (1st experiment) and 18% and 8% (2nd experiment)of control plants on which ethyl acetate extract of nutrient broth was sprayed. Both disease severity and lesion length of the red pepper plants sprayed with SH122 extract were even lower than those of the DL-B-amino-n-butyric acid-treated plants, which is known as a strong inducer of resistance against phytophthora blight in pepper. Bacterial metabolite inducing resistance against phytophthora blight in red pepper plants is appeared to reside in bacterial cells of SH122 since ethyl acetate extract of bacterial cells induced resistance whereas extract of culture fitrate didn't. The SH122 was identified as Bacillus pumilus, certain strains of which were well known as plant growth-promoting rhizobacteria (PGPR) inducing systemic resistance in several plants, with fatty acid analysis by MIDI system. The SH122 itself or ethyl acetate extract of its culture did not showed any antifungal activity against Phytophthora capsici by dual culture on potato dextrose agar. All of these results suggest that Bacillus pumilus SH122 produces compound(s) induce resistance strongly against phytophthora blight in red pepper plants.