Plant growth and yield is adversely affected by soil salinity. Salt tolerant plant growth-promoting rhizobacteria (PGPR) strain IG 3 was isolated from rhizosphere of wheat plants. The isolate IG 3 was able to grow in presence of NaCl ranging from 0 to 20% in Luria Bertani medium. The present study was planned to evaluate the role of inoculation of PGPR strain IG 3 and its efficacy in augmenting salt tolerance in oat (Avena sativa) under NaCl stress (100 mM). The physiological parameter such as shoot length, root length, shoot dry weight, root dry weight and relative water content (RWC) were remarkably higher in IG 3 inoculated plants in comparison to un-inoculated plants under NaCl stress. Similarly, the biochemical parameters such as proline content, electrolyte leakage and malondialdehyde (MDA) content and activities of antioxidant enzymes were analyzed and found to be notably lesser in IG 3 inoculated oat plants in contrast to un-inoculated plants under salt stress. Inoculation of IG 3 strain to oat seedlings under salt stress positively modulated the expression profile of rbcL and WRKY1 genes. Root colonization of root surface and interior was demonstrated using scanning electron microscopy and tetrazolium staining, respectively. Due these outcomes, it could be implicated that inoculation of PGPR strain IG 3 enhanced plant growth under salt stress condition. This study demonstrates that PGPR play an imperative function in stimulating salt tolerance in plants and can be used as biofertilizer to enhance growth of crops in saline areas.

盐分对植物的生长和产量有不利影响。从小麦植株的根际中分离出了耐盐植物促生根瘤菌（PGPR）菌株IG 3。分离株IG 3能够在Luria Bertani培养基中的NaCl存在下（从0％到20％）生长。本研究计划，以评估促生菌菌株IG 3及其在燕麦增强耐盐性功效的接种作用（燕麦）在NaCl应力（100 mM）下。与NaCl胁迫下未接种的植株相比，接种IG 3的植株的生理参数，例如苗长，根长，枝干重，根干重和相对含水量（RWC）明显更高。同样，分析了脯氨酸含量，电解质泄漏和丙二醛（MDA）含量等生化参数以及抗氧化酶的活性，发现与盐胁迫下未接种植物相比，接种IG 3的燕麦植物中的蛋白质含量要低得多。在盐胁迫下将IG 3菌株接种到燕麦幼苗上可正向调节rbcL和WRKY1的表达谱基因。分别使用扫描电子显微镜和四唑鎓染色证明了根表面和内部的根定殖。由于这些结果，可以暗示在盐胁迫条件下接种PGPR菌株IG 3可以促进植物生长。这项研究表明，PGPR在刺激植物的耐盐性中起着必不可少的作用，并且可以用作生物肥料以增强盐碱地区农作物的生长。