title: Rhizobacterial Strain Bacillus megaterium BOFC15 Induces Cellular Polyamine Changes that Improve Plant Growth and Drought Resistance.
abstract: Plant-growth-promoting rhizobacteria can improve plant growth, development, and stress adaptation. However, the underlying mechanisms are still largely unclear. We investigated the effects of Bacillus megaterium BOFC15 on Arabidopsis plants. BOFC15 produced and secreted spermidine (Spd), a type of polyamine (PA) that plays an important role in plant growth. Moreover, BOFC15 induced changes in the cellular PAs of plants that promoted an increase of free Spd and spermine levels. However, these effects were remarkably abolished by the addition of dicyclohexylamine (DCHA), a Spd biosynthetic inhibitor. Additionally, the inoculation with BOFC15 remarkably increased plant biomass, improved root system architecture, and augmented photosynthetic capacity. Inoculated plants also displayed stronger ability to tolerate drought stress than non-inoculated (control) plants. Abscisic acid (ABA) content was notably higher in the inoculated plants than in the control plants under drought stress and polyethylene glycol (PEG)-induced stress conditions. However, the BOFC15-induced ABA synthesis was markedly inhibited by DCHA. Thus, microbial Spd participated in the modulation of the ABA levels. The Spd-producing BOFC15 improved plant drought tolerance, which was associated with altered cellular ABA levels and activated adaptive responses.
authors.affiliation: School of Life Science and Technology, Tongji University, Shanghai 200092, China. czhou1224@hotmail.com.|Key Laboratory of Bio-Organic Fertilizer Creation, Ministry of Agriculture, Anhui Science and Technology University, Bengbu 233100, China. czhou1224@hotmail.com.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Bio-Organic Fertilizer Creation, Ministry of Agriculture, Anhui Science and Technology University, Bengbu 233100, China. mazy@ahstu.edu.cn.
authors.forename: Zhongyou
authors.initials: Z
authors.lastname: Ma
authors.affiliation: School of Life Science and Technology, Tongji University, Shanghai 200092, China. putaojiuvsduyao@126.com.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Bio-Organic Fertilizer Creation, Ministry of Agriculture, Anhui Science and Technology University, Bengbu 233100, China. xiaox@ahstu.edu.cn.
authors.forename: Xin
authors.initials: X
authors.lastname: Xiao
authors.affiliation: Key Laboratory of Bio-Organic Fertilizer Creation, Ministry of Agriculture, Anhui Science and Technology University, Bengbu 233100, China. xiey@ahstu.edu.cn.
authors.forename: Yue
authors.initials: Y
authors.lastname: Xie
authors.affiliation: School of Life Science and Technology, Tongji University, Shanghai 200092, China. zhujian1@tongji.edu.cn.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Bio-Organic Fertilizer Creation, Ministry of Agriculture, Anhui Science and Technology University, Bengbu 233100, China. jfwang1@aliyun.com.
authors.forename: Jianfei
authors.initials: J
authors.lastname: Wang
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D017360:Arabidopsis / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology*; D001410:Bacillus megaterium / Q000472:pathogenicity / Q000502:physiology*; D018533:Biomass; D055864:Droughts; D010788:Photosynthesis; D011092:Polyethylene Glycols / Q000633:toxicity; D027343:Rhizome / Q000382:microbiology*; D013095:Spermidine / Q000378:metabolism*; D013312:Stress, Physiological
chemical_list: D011092:Polyethylene Glycols; D000040:Abscisic Acid; D013095:Spermidine
keywords: Arabidopsis thaliana; Bacillus megaterium; abscisic acid; drought tolerance; polyamines