Journal Article

Bacillus aryabhattai SRB02 tolerates oxidative and nitrosative stress and promotes the growth of soybean by modulating the production of phytohormones

Kang, Sang-Mo, Hussain, Adil, Shahzad, Raheem, Mun, Bong-Gyu, Yun, Byung-Wook, Park, Yeon-Gyeong, Kim, Ah-Yeong, Oh, Kyeong Yeol, Seo, Chang-Woo, Lee, Sang-Uk, Lee, Dong Yeol, Lee, In-Jung

2017

Overview

Plant growth promoting rhizobacteria (PGPR) are diverse, naturally occurring bacteria that establish a close association with plant roots and promote the growth and immunity of plants. Established mechanisms involved in PGPR-mediated plant growth promotion include regulation of phytohormones, improved nutrient availability, and antagonistic effects on plant pathogens. In this study, we isolated a bacterium from the rhizospheric soil of a soybean field in Chungcheong buk-do, South Korea. Using 16S rRNA sequencing, the bacterium was identified as Bacillus aryabhattai strain SRB02. Here we show that this strain significantly promotes the growth of soybean. Gas chromatography-mass spectrometry analysis showed that SRB02 produced significant amounts of abscisic acid, indole acetic acid, cytokinin and different gibberellic acids in culture. SRB02-treated soybean plants showed significantly better heat stress tolerance than did untreated plants. These plants also produced consistent levels of ABA under heat stress and exhibited ABA-mediated stomatal closure. High levels of IAA, JA, GA12, GA4, and GA7, were recorded in SRB02-treated plants. These plants produced longer roots and shoots than those of control plants. B. aryabhattai SRB02 was found to be highly tolerant to oxidative stress induced by H2O2 and MV potentiated by high catalase (CAT) and superoxide dismutase (SOD) activities. SRB02 also tolerated high nitrosative stress induced by the nitric oxide donors GSNO and CysNO. Because of these attributes, B. aryabhattai SRB02 may prove to be a valuable resource for incorporation in biofertilizers and other soil amendments that seek to improve crop productivity.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Abscisic acid / Abscisic Acid - analysis / Abscisic Acid - metabolism / Acetic acid / Agricultural production / Analysis / Azospirillum brasilense / Bacillus / Bacillus - genetics / Bacillus - isolation & purification / Bacillus - metabolism / Bacillus aryabhattai / Bacteria / Biofertilizers / Biology and Life Sciences / Catalase / Catalase - metabolism / Crop production / Ecology and Environmental Sciences / Fertilizers / Gas chromatography / Gas Chromatography-Mass Spectrometry / Genetic aspects / Gibberellins / Gibberellins - analysis / Gibberellins - metabolism / Glycine max - growth & development / Glycine max - metabolism / Glycine max - microbiology / Heat stress / Heat tolerance / Hydrogen peroxide / Hydrogen Peroxide - toxicity / Immunity / Indoleacetic acid / Indoleacetic Acids - analysis / Indoleacetic Acids - metabolism / Mass spectrometry / Mass spectroscopy / Microorganisms / Microscopy, Electron, Scanning / Nitric oxide / Nitric Oxide Donors - toxicity / Nutrient availability / Oxidative stress / Oxidative Stress - drug effects / Physical Sciences / Phytohormones / Plant growth / Plant growth promoting substances / Plant Growth Regulators - analysis / Plant Growth Regulators - metabolism / Plant hormones / Plant roots / Plant Roots - growth & development / Plant Roots - metabolism / Plant Roots - microbiology / Pseudomonas / Pseudomonas aeruginosa / Pseudomonas putida / Rhizosphere / RNA sequencing / RNA, Ribosomal, 16S - chemistry / RNA, Ribosomal, 16S - genetics / RNA, Ribosomal, 16S - metabolism / Roots / rRNA 16S / Sequence Analysis, DNA / Shoots / Soil amendment / Soil improvement / Soil Microbiology / Soybeans / Stomata / Strain / Superoxide dismutase / Superoxide Dismutase - metabolism / Symbiosis / Temperature