Under the stressed conditions plant growth-promoting rhizobacteria (PGPR) are able to stimulate plant growth through several mechanisms, including antioxidants alleviation, regulation of stress responsive genes and phytohormones etc. Present study is conducted to investigate the impact of Paenibacillus lentimorbus B-30488 inoculation on salinity and drought stress mitigation in Arabidopsis thaliana through modulation in defense enzymes, phyto-hormones and root system architecture associated gene expression profiling. In vitro experiments clearly demonstrated the role of B-30488 in stimulating the root length, branches, lateral root formation and biomass under salinity and drought stress. The inoculation of B-30488 modulated the phytohormones levels to protect the plants from salinity and drought stress. Similarly, defence enzymes were also activated under the stressed conditions, but B-30488 inoculation reduced the antioxidants content during salinity and drought stress as compared to their respective controls. Microscopy results showed decrease in lateral roots hair formation under both stresses and B-30488 inoculation not only mitigate but also enhanced the lateral root formation. Gene expression analysis through real time polymerase chain reaction (RT-PCR) showed modulated expression of several genes related to root development, stress and lateral root formation in B-30488 inoculated seedlings. Results based on the present study, B-30488 is also involved in alteration root architecture, its growth regulation via modulation in phytohormones and genes expression and overall significant improvement in plant growth under stress conditions.

在胁迫条件下，植物生长促进根际细菌 (PGPR) 能够通过多种机制刺激植物生长，包括抗氧化剂缓解、胁迫响应基因和植物激素的调节等。 本研究旨在研究接种类芽孢杆菌( Paenibacillus lentimorbus B-30488)的影响拟南芥盐分和干旱胁迫缓解通过调节防御酶、植物激素和根系统结构相关的基因表达谱。体外实验清楚地证明了 B-30488 在盐分和干旱胁迫下刺激根长、分枝、侧根形成和生物量的作用。B-30488 的接种调节植物激素水平以保护植物免受盐分和干旱胁迫。类似地，防御酶也在压力条件下被激活，但与它们各自的对照相比，B-30488 接种降低了盐度和干旱胁迫期间的抗氧化剂含量。显微镜检查结果显示，在压力和 B-30488 接种下，侧根毛发形成减少，不仅减轻而且增强了侧根形成。通过实时聚合酶链反应 (RT-PCR) 进行的基因表达分析显示，在 B-30488 接种的幼苗中，与根发育、胁迫和侧根形成相关的几个基因的表达受到调节。基于本研究的结果，B-30488 还参与改变根系结构，通过调节植物激素和基因表达来调节其生长，以及在胁迫条件下植物生长的整体显着改善。