Laboratory of Agricultural Chemistry, School of Agriculture, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece.
International Hellenic University, 57001, Thermi, Greece.
Sci Rep. 2020 Sep 9;10(1):14857. doi: 10.1038/s41598-020-71652-0.
Plant growth promoting rhizobacteria (PGPR) are able to provide cross-protection against multiple stress factors and facilitate growth of their plant symbionts in many ways. The aim of this study was to isolate and characterize rhizobacterial strains under natural conditions, associated with naturally occurring representatives of wild plant species and a local tomato cultivar, growing in differently stressed Mediterranean ecosystems. A total of 85 morphologically different rhizospheric strains were isolated; twenty-five exhibited multiple in vitro PGP-associated traits, including phosphate solubilization, indole-3-acetic acid production, and 1-aminocyclopropane-1-carboxylate deaminase activity. Whole genome analysis was applied to eight selected strains for their PGP potential and assigned seven strains to Gammaproteobacteria, and one to Bacteroidetes. The genomes harboured numerous genes involved in plant growth promotion and stress regulation. They also support the notion that the presence of gene clusters with potential PGP functions is affirmative but not necessary for a strain to promote plant growth under abiotic stress conditions. The selected strains were further tested for their ability to stimulate growth under stress. This initial screening led to the identification of some strains as potential PGPR for increasing crop production in a sustainable manner.
植物促生根际细菌（PGPR）能够以多种方式提供对多种胁迫因子的交叉保护，并促进其植物共生体的生长。本研究的目的是在自然条件下分离和鉴定与野生植物种和当地番茄品种相关的根际细菌菌株，这些植物生长在具有不同胁迫的地中海生态系统中。共分离出 85 株形态不同的根际菌株；其中 25 株表现出多种体外与植物促生相关的特性，包括磷酸盐溶解、吲哚-3-乙酸产生和 1-氨基环丙烷-1-羧酸脱氨酶活性。对 8 株选定的菌株进行全基因组分析，以评估其植物促生潜能，并将 7 株菌株分配到γ-变形菌门，1 株菌株分配到拟杆菌门。基因组中含有许多与植物生长促进和应激调节相关的基因。这也支持了这样一种观点，即存在具有潜在植物促生功能的基因簇是肯定的，但对于菌株在非生物胁迫条件下促进植物生长来说并非必需。进一步测试了选定的菌株在胁迫下刺激生长的能力。这一初步筛选确定了一些菌株具有作为潜在植物促生菌的潜力，可以以可持续的方式提高作物产量。
