Department of Biology, College of Science, United Arab Emirates University, 15551, Al Ain, United Arab Emirates.
Khalifa Center for Genetic Engineering and Biotechnology, United Arab Emirates University, 15551, Al Ain, United Arab Emirates.
World J Microbiol Biotechnol. 2022 Aug 26;38(11):207. doi: 10.1007/s11274-022-03392-4.
The plant growth-promoting rhizobacteria (PGPRs) improve plant growth and fitness by multiple direct (nitrogen fixation and phosphate solubilization) and indirect (inducing systematic resistance against phytopathogens, soil nutrient stabilization, and maintenance) mechanisms. Nevertheless, the mechanisms by which PGPRs promote plant growth in hot and arid environments remain poorly recorded. In this study, a comparative genome analysis of two phosphate solubilizing bacteria, Pseudomonas atacamensis SM1 and Pseudomonas toyotomiensis SM2, isolated from the rhizosphere of date palm was performed. The abundance of genes conferring stress tolerance (chaperones, heat shock genes, and chemotaxis) and supporting plant growth (plant growth hormone, root colonization, nitrogen fixation, and phosphate solubilization) were compared among the two isolates. This study further evaluated their functions, metabolic pathways, and evolutionary relationship. Results show that both bacterial strains have gene clusters required for plant growth promotion (phosphate solubilization and root colonization), but it is more abundant in P. atacamensis SM1 than in P. toyotomiensis SM2. Genes involved in stress tolerance (mcp, rbs, wsp, and mot), heat shock, and chaperones (hslJ and hslR) were also more common in P. atacamensis SM1. These findings suggest that P. atacamensis SM1could have better adaptability to the hot and arid environment owing to a higher abundance of chaperone genes and heat shock proteins. It may promote plant growth owing to a higher load of root colonization and phosphate solubilization genes and warrants further in vitro study.
植物促生根际细菌（PGPR）通过多种直接（固氮和溶磷）和间接（诱导对植物病原体的系统抗性、土壤养分稳定和维持）机制来促进植物生长和适应性。然而，PGPR 在炎热和干旱环境中促进植物生长的机制仍记录甚少。在这项研究中，对从枣椰树根际分离的两种溶磷细菌 Pseudomonas atacamensis SM1 和 Pseudomonas toyotomiensis SM2 进行了比较基因组分析。比较了两个分离株中赋予应激耐受（伴侣蛋白、热休克基因和趋化性）和支持植物生长（植物生长激素、根定植、固氮和溶磷）的基因丰度。本研究进一步评估了它们的功能、代谢途径和进化关系。结果表明，两株细菌都具有促进植物生长所必需的基因簇（溶磷和根定植），但 P. atacamensis SM1 中的基因簇比 P. toyotomiensis SM2 更为丰富。与应激耐受（mcp、rbs、wsp 和 mot）、热休克和伴侣蛋白（hslJ 和 hslR）相关的基因在 P. atacamensis SM1 中也更为常见。这些发现表明，由于伴侣蛋白基因和热休克蛋白的丰度较高，P. atacamensis SM1 可能对炎热干旱的环境具有更好的适应性。它可能通过更高的根定植和溶磷基因负荷来促进植物生长，值得进一步进行体外研究。
