Salt Stress Mitigating Potential of Halotolerant/Halophilic Plant Growth Promoting

Abstract

In the current study, the PGP (production of siderophore and IAA, fixation of nitrogen and solubilization of phosphate) potential of forty-five bacterial isolates comprising sixteen genera (Marinibacillus, Zhihengliuella, Bacillus, Nesterenkonia, Halobacillus, Promicromonospora, Terribacillus, Jeotgalibacillus, Staphylococcus, Oceanobacillus, Virgibacillus, Halomonas, Gracilibacillus, Planococcus, Thalassobacillus and Microbacterium) was investigated. Among these forty-five bacterial isolates, most of the isolates (40 isolates) possess plant growth promoting potential. Four bacterial isolates [Marinibacillus sp. (EM1), Zhihengliuella salsuginis (EM30), Planococcus sp. (EK9), and Promicromonospora sp. (EK12)] possessing PGP traits were applied on the barley grown under salt (NaCl) stress in a hydroponic system. Comparing to the un-inoculated group, all the four bacterial isolates significantly improved plant growth that inhibited with NaCl (200 mM) stress. The growth rate of the plants inoculated with Zhihengliuella salsuginis (EM30), Promicromonospora sp. (EK12), Planococcus sp. (EK9), and Marinibacillus sp. (EM1) was 81.86, 80.51, 70.62 and 69.22, respectively. As far as we know, this is the first report showing the PGP potential of Marinibacillus sp. (EM1), Bacillus horikoshii (EM9), Bacillus patagoniensis (EM12), Bacillus agaradhaerens (EK13), Oceanobacillus profundus (EM26) Thalassobacillus devorans (EM34) and Promicromonospora sp. (EK12).