Exploration of endophytic bacteria with multiple plant growth promoting (PGP) attributes is considered as an eco-friendly and cost-effective alternative to agricultural chemicals for increasing crop productivity. In the present endeavor, healthy chickpea plants (Cicer arietinum L.) collected from district Birbhum, West Bengal, India were subjected for the isolation of endophytic bacteria having multifarious PGP properties. One potent endophytic Gram positive bacterial strain CNE6 was isolated from the nodule of chickpea and was identified as Bacillus siamensis based on 16S rDNA sequence homologies. The isolate showed a number of PGP properties like phosphate solubilization, IAA production, nitrogen fixation, hydroxamate type of siderophore production and ACC deaminase activities. The isolate CNE6 produced 33.27 ± 2.16 μg/mL of IAA in the presence of tryptophan. Production of IAA was also confirmed by HPLC analysis and it was found effective for inducing lateral root branching in chickpea. In addition, the isolate displayed significant antagonistic activity against a number of plant pathogenic fungi when tested by dual culture overlay and agar well diffusion assay. 50 % cell free supernatant of CNE6 was found effective for 60–80 % inhibition of radial growth of pathogenic fungi tested. Scanning electron microscopic observation revealed massive degradation of pathogenic fungal mycelia by the antifungal metabolites of CNE6. LC–MS analysis of bacterial lipopeptides suggested the production of antifungal antibiotics like surfactin, fengycin and iturin by the isolate. The presence of genes encoding antifungal lipopeptides was also confirmed by PCR amplification using specific primers. Green fluorescent protein (GFP) tagging of CNE6 using broad host range plasmid vector (pDSK-GFPuv) followed by colonization study indicated very good host colonization potential of the isolate and its probable movement through xylem vessels. Enhanced shoot and root length and chlorophyll content upon treatment with CNE6 as observed in in vivo pot experiments also supported the positive role of the endophytic isolate on overall development and growth of the chickpea plants. This is the first report of Bacillus siamensis as an endophyte of Cicer arietinum L. which can be successfully applied for improving the productivity of this crop plant.

探索具有多种植物生长促进 (PGP) 属性的内生细菌被认为是一种环保且具有成本效益的农业化学品替代品，可提高作物生产力。在目前的努力中，从印度西孟加拉邦 Birbhum 区收集的健康鹰嘴豆植物 ( Cicer arietinum L.) 被用于分离具有多种 PGP 特性的内生细菌。从鹰嘴豆根瘤中分离到一株强效内生革兰氏阳性菌CNE6，经鉴定为暹罗芽孢杆菌基于 16S rDNA 序列同源性。该分离物显示出许多 PGP 特性，如磷酸盐增溶、IAA 产生、固氮、异羟肟酸盐类型的铁载体产生和 ACC 脱氨酶活性。在色氨酸存在下，分离株 CNE6 产生 33.27 ± 2.16 μg/mL 的 IAA。HPLC 分析也证实了 IAA 的产生，并发现它对诱导鹰嘴豆侧根分枝有效。此外，当通过双重培养覆盖和琼脂孔扩散试验进行测试时，该分离株显示出对许多植物病原真菌的显着拮抗活性。发现 50% 的 CNE6 无细胞上清液可有效抑制所测试的病原真菌的径向生长 60-80%。扫描电子显微镜观察揭示了 CNE6 的抗真菌代谢物对病原真菌菌丝体的大量降解。细菌脂肽的 LC-MS 分析表明，分离株产生了抗真菌抗生素，如表面活性素、芬奇素和伊图林。编码抗真菌脂肽的基因的存在也通过使用特定引物的 PCR 扩增得到证实。使用广泛的宿主范围质粒载体 (pDSK-GFPuv) 对 CNE6 进行绿色荧光蛋白 (GFP) 标记，然后进行定植研究，表明该分离株具有非常好的宿主定植潜力及其可能通过木质部血管的运动。用 CNE6 处理后增加的芽和根长度和叶绿素含量，如在 细菌脂肽的 LC-MS 分析表明，分离株产生了抗真菌抗生素，如表面活性素、芬奇素和伊图林。编码抗真菌脂肽的基因的存在也通过使用特定引物的 PCR 扩增得到证实。使用广泛的宿主范围质粒载体 (pDSK-GFPuv) 对 CNE6 进行绿色荧光蛋白 (GFP) 标记，然后进行定植研究，表明该分离株具有非常好的宿主定植潜力及其可能通过木质部血管的运动。用 CNE6 处理后增加的芽和根长度和叶绿素含量，如在 细菌脂肽的 LC-MS 分析表明，分离株产生了抗真菌抗生素，如表面活性素、芬奇素和伊图林。编码抗真菌脂肽的基因的存在也通过使用特定引物的 PCR 扩增得到证实。使用广泛的宿主范围质粒载体 (pDSK-GFPuv) 对 CNE6 进行绿色荧光蛋白 (GFP) 标记，然后进行定植研究，表明该分离株具有非常好的宿主定植潜力及其可能通过木质部血管的运动。用 CNE6 处理后增加的芽和根长度和叶绿素含量，如在 使用广泛的宿主范围质粒载体 (pDSK-GFPuv) 对 CNE6 进行绿色荧光蛋白 (GFP) 标记，然后进行定植研究，表明该分离株具有非常好的宿主定植潜力及其可能通过木质部血管的运动。用 CNE6 处理后增加的芽和根长度和叶绿素含量，如在 使用广泛的宿主范围质粒载体 (pDSK-GFPuv) 对 CNE6 进行绿色荧光蛋白 (GFP) 标记，然后进行定植研究，表明该分离株具有非常好的宿主定植潜力及其可能通过木质部血管的运动。用 CNE6 处理后增加的芽和根长度和叶绿素含量，如在体内盆栽实验也支持内生分离物对鹰嘴豆植物的整体发育和生长的积极作用。这是暹罗芽孢杆菌作为Cicer arietinum L.内生菌的首次报道，可成功应用于提高该作物的生产力。