Albdaiwi Randa N, Khyami-Horani Hala, Ayad Jamal Y, Alananbeh Kholoud M, Al-Sayaydeh Rabea
Department of Biological Sciences, Faculty of Science, The University of Jordan, Amman, Jordan.
Department of Horticulture and Crop Science, Faculty of Agriculture, The University of Jordan, Amman, Jordan.
Front Microbiol. 2019 Jul 23;10:1639. doi: 10.3389/fmicb.2019.01639. eCollection 2019.
Plant growth promoting rhizobacteria (PGPR) are beneficial microorganisms that can be utilized to improve plant responses against biotic and abiotic stresses. In this study, 74 halotolerant bacterial isolates were isolated from rhizosphere and endorhizosphere of durum wheat ( subsp. ) plants cultivated in saline environments in the Ghor region near the east of the Dead Sea. partial sequences and phylogenetic analysis of 62 isolates showed clear clustering of the isolates into three phyla: Firmicutes (61.3%), Proteobacteria (29.0%), and Actinobacteria (9.7%). At the genus level, the majority of them were grouped within the , and genera. The isolates, which possessed plant growth promoting traits including nitrogen fixation, ACC deaminase activity, auxin production, inorganic phosphate solubilization and siderophore production, were selected. The effect of the inoculation of selected PGPR strains on growth of salt sensitive and salt tolerant durum wheat genotypes under high salt stress conditions was evaluated. Six halotolerant PGPR strains were able to improve survival in inoculated plants under high salinity stress conditions as reflected in higher germination percentages and seedling root growth when compared with non-inoculated plants. Furthermore, three halotolerant PGPR strains were able to improve durum wheat tolerance to water deficit stress. In addition, antagonistic effect in four halotolerant PGPR strains against an aggressive pathogenic isolate of that causes crown rot disease was observed in a dual culture assay. In conclusion, the halotolerant PGPR strains described in this study might have great potential to improve durum wheat productivity under different stress conditions.
植物促生根际细菌（PGPR）是一类有益微生物，可用于增强植物对生物和非生物胁迫的抗性。本研究从死海以东附近戈尔地区盐渍环境中种植的硬粒小麦（亚种）植物的根际和根内分离出74株耐盐细菌菌株。对62株菌株的部分序列和系统发育分析表明，这些菌株明显聚为三个门：厚壁菌门（61.3%）、变形菌门（29.0%）和放线菌门（9.7%）。在属水平上，它们大多归为、和属。挑选出具有促进植物生长特性（包括固氮、ACC脱氨酶活性、生长素产生、无机磷溶解和铁载体产生）的菌株。评估了所选PGPR菌株接种对高盐胁迫条件下盐敏感和耐盐硬粒小麦基因型生长的影响。与未接种的植株相比，6株耐盐PGPR菌株能够提高接种植株在高盐胁迫条件下的存活率，表现为更高的发芽率和幼苗根生长。此外，3株耐盐PGPR菌株能够提高硬粒小麦对水分亏缺胁迫的耐受性。另外，在双培养试验中观察到4株耐盐PGPR菌株对一种导致冠腐病的致病性强的病原菌分离株具有拮抗作用。总之，本研究中描述的耐盐PGPR菌株在不同胁迫条件下提高硬粒小麦生产力方面可能具有巨大潜力。
