Drought ranks among the most severe environmental stressors that adversely affect crop productivity. Use of stress-tolerant plant growth-promoting rhizobacteria (PGPR) is expected to ameliorate the drought stress in plants. Therefore, in this study, a novel strain, Pseudomonas azotoformans FAP5 with multifunctional traits was obtained from screening of 50 indigenous isolates. The criteria for selection of most promising strain were based on tolerance to water stress, production of PGP traits and biofilm-forming ability in vitro. Further, inoculation response of FAP5 on wheat growth parameters and physiological attributes under different drought conditions was executed under pot experiment. The drought-tolerant FAP5 strain revealed production of exopolysaccharides (EPS), indole 3 acetic acid (IAA), solubilized tricalcium phosphate and exhibited 1-aminpcyclopropane-1-carboxylate (ACC) deaminase (41.58 ± 2.10 μmol α-KB/mg Pr h) activity. ACC deaminase (acdS) and biofilm-associated (AdnA and FliC) genes were confirmed by PCR-based method. Production of PGP traits and biofilm development by FAP5 was exhibited even at water stress condition in vitro. The inoculated wheat plants with FAP5 strain were grown under drought stress showed significant (P < 0.05) improvement in growth attributes, photosynthetic pigment efficiency and other physiological attributes. Similarly, a significant (P < 0.05) antioxidative enzymatic activities in FAP5-inoculated plant were observed compared to uninoculated plants. Under drought stress condition, biofilm development by FAP5 was enhanced significantly and root colonization by inoculant strain was confirmed by viable count and scanning electron microscopy (SEM). The findings indicated that FAP5 strain is effective to drought stress alleviation in wheat plants through various biochemical mechanisms.

干旱是对作物生产力产生不利影响的最严重的环境压力之一。预期使用耐胁迫的植物促生根瘤菌（PGPR）可以减轻植物的干旱胁迫。因此，在这项研究中，一种新菌株，假单胞菌假单胞菌具有多功能性的FAP5是通过筛选50个本地分离株获得的。选择最有希望的菌株的标准是基于对水分胁迫的耐受性，PGP性状的产生和体外生物膜形成能力。此外，在盆栽试验中，对不同干旱条件下FAP5对小麦生长参数和生理特性的接种反应进行了研究。耐旱的FAP5菌株显示出胞外多糖（EPS），吲哚3乙酸（IAA），溶解的磷酸三钙的生成并表现出1-氨基环丙烷-1-羧酸盐（ACC）脱氨酶（41.58±2.10μmolα-KB/ mg Pr h ）活动。ACC脱氨酶（acdS）和生物膜相关的（AdnA和FliC基因通过基于PCR的方法确认。FAP5产生的PGP性状和生物膜的发育甚至在体外水分胁迫条件下也表现出来。带有FAP5株的接种小麦植物在干旱胁迫下 生长，其生长特性，光合色素效率和其他生理特性显着提高（P <0.05）。同样，显著（P 与未接种的植物相比，在接种FAP5的植物中观察到<0.05）的抗氧化酶活性。在干旱胁迫条件下，FAP5显着增强了生物膜的发育，并通过活计数和扫描电子显微镜（SEM）证实了接种菌株的根部定植。研究结果表明，FAP5菌株通过多种生化机制可有效缓解小麦植物的干旱胁迫。