Evaluating the salt resistance of Arabidopsis thaliana induced by plant growth-promoting rhizobacteria (PGPR) isolated from Can Gio mangrove forest

Abstract

As soil salinization is a major concern of modern agriculture and an expected threat in climate change scenarios, special effort will be required for maintaining crop production under salt stress. The use of plant growth-promoting rhizobacteria (PGPR) is a promising agricultural practice to help less salt tolerant crops to maintain an acceptable level of productivity under higher salt concentrations. Here, we have isolated the PGPR from the rhizosphere soil in Can Gio Mangrove Forest, Vietnam. Fifteen isolates of bacteria were successfully isolated on medium containing 10 % NaCl. Subsequently, to investigate the effects of PGPR isolates on the growth of Arabidopsis thaliana, seeds were treated with the PGPR and observed the germination as well as the seedling growth. Under stress condition, all bacteria inhibited the germination, however, 02NP01, 04PP02 and 06NS01, identified as Bacillus thuringiensis, Vibrio and Halomonas elongata, respectively, could promote Arabidopsis thaliana seedling growth compared to the control. Further analysis found that three bacteria exhibited the ability to fix nitrogen, solubilize inorganic phosphorus and produce phytohormone-auxin. In addition, under normal condition, Bacillus and Vibrio significantly increased A. thaliana germination, after treatment with Bacillus and Vibrio the seed germination rate increased by 36.60 % and 69.76 % respectively compared to the control. Our research shows that isolated potential rhizobacterial strains may be used as an effective tool for enhancing Arabidopsis thaliana seedling growth under salinity stress.