title: Bacillus aryabhattai SRB02 tolerates oxidative and nitrosative stress and promotes the growth of soybean by modulating the production of phytohormones.
abstract: 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.
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Yeon-Gyeong
authors.initials: YG
authors.lastname: Park
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Bong-Gyu
authors.initials: BG
authors.lastname: Mun
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Sang-Mo
authors.initials: SM
authors.lastname: Kang
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu, Republic of Korea.|Department of Agriculture, Abdul Wali Khan University, Mardan, Khyber Pakhtunkhwa, Pakistan.
authors.forename: Adil
authors.identifier: http://orcid.org/0000-0002-7803-429X
authors.initials: A
authors.lastname: Hussain
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Raheem
authors.initials: R
authors.lastname: Shahzad
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Chang-Woo
authors.initials: CW
authors.lastname: Seo
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Ah-Yeong
authors.initials: AY
authors.lastname: Kim
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Sang-Uk
authors.initials: SU
authors.lastname: Lee
authors.affiliation: Gyeongnam Oriental Medicinal Herb Institute, Sancheong, Republic of Korea.
authors.forename: Kyeong Yeol
authors.initials: KY
authors.lastname: Oh
authors.affiliation: Gyeongnam Oriental Medicinal Herb Institute, Sancheong, Republic of Korea.
authors.forename: Dong Yeol
authors.initials: DY
authors.lastname: Lee
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: In-Jung
authors.initials: IJ
authors.lastname: Lee
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Byung-Wook
authors.initials: BW
authors.lastname: Yun
mesh_terms: D000040:Abscisic Acid / Q000032:analysis / Q000378:metabolism; D001407:Bacillus / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D005875:Gibberellins / Q000032:analysis / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000633:toxicity; D007210:Indoleacetic Acids / Q000032:analysis / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D020030:Nitric Oxide Donors / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects; D010937:Plant Growth Regulators / Q000032:analysis / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D058441:Rhizosphere; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D013025:Glycine max / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology*; D013482:Superoxide Dismutase / Q000378:metabolism; D013559:Symbiosis; D013696:Temperature
chemical_list: D005875:Gibberellins; D007210:Indoleacetic Acids; D020030:Nitric Oxide Donors; D010937:Plant Growth Regulators; D012336:RNA, Ribosomal, 16S; C030737:indoleacetic acid; D000040:Abscisic Acid; D006861:Hydrogen Peroxide; C007842:gibberellic acid; D002374:Catalase; D013482:Superoxide Dismutase