Drought-tolerant rhizobacteria with predicted functional traits enhanced wheat growth and P uptake under moderate drought and low P-availability

作者：Benmrid B, Ghoulam C, Ammar I, Nkir D, Saidi R, Staropoli A, Iacomino G, ELhajjami E, Cheto S, Geistlinger J, Idbella M, Bargaz A · 发表于：Microbiological research · 年份：2024 · DOI：10.1016/j.micres.2024.127795 · 研究领域：Triticum、Droughts、Soil Microbiology、Rhizosphere、Plant Roots、Phosphates、Bacteria、Phosphorus、Stress, Physiological

This study aims to investigate the effect of isolated drought-tolerant rhizobacteria, spanning various groups, such as nitrogen-fixing bacteria (NFB), phosphate solubilizing bacteria (PSB), and other plant growth promoting rhizobacteria (PGPR), on the growth of wheat (Triticum durum) plants, focusing on various morphological and physiological responses under moderate drought and low-P availability. Among 343 rhizobacterial morphotypes, 16 exhibited tolerance to NaCl and PEG-6000. These included 8 PSB, 4 NFB, and 4 osmotolerant-PGPR groups, distributed across 14 different genera. Biochemical characterization showcased diverse PGP capabilities, particularly in P solubilization. The dynamic responses of drought-tolerant PSB to salt and PEG-6000-induced drought stress involved variations in organic acid (OA) secretion, with specific acids, including palmitic, lactic, and stearic, playing crucial roles in enhancing available P fractions. Inoculation with rhizobacteria significantly increased both shoot (SDW) and root (RDW) dry weights of wheat plants, as well as rhizosphere available P. PSB11 (Arthrobacter oryzae) emerged as the most effective strain, plausibly due to its positive impact on root morphological traits (length, surface, and volume). Other isolates, PSB10 (Priestia flexa), PSB13 (Bacillus haynesii), and particularly PGPR2 (Arthrobacter pascens) significantly increased shoot P content (up to 68.91 %), with a 2-fold increase in chlorophyll content. The correlation analy...