Salinity is a major abiotic stress for crop plants that cause reduced food production. The application of plant growth-promoting microorganisms can improve the adaptability of plants to biotic and abiotic stresses. Therefore, in the current study, we aimed to enhance the mitigation effects of artificially applied rhizobacterium Klebsiella variicola AY13 on salinity stress in Trifolium repens L. The results suggested that AY13 innately produced indole-3-acetic acid and accelerated the morphological adaptation of T. repens to salt stress conditions. Furthermore, AY13 promotes a Trp-dependent pathway for indole-3-acetic acid (IAA) production, as adding L-tryptophan (L-Trp) increased IAA production in pure culture. AY13 improved plant growth by maintaining relative water content and minimizing water loss in excised leaves. Moreover, AY13 inoculation significantly reduced the endogenous levels of abscisic acid and antioxidants such as glutathione and catalase. These results suggest that AY13 plays a crucial role in reprogramming stress-related metabolism and enhancing plant stress tolerance.

Appropriate water level is the primary factor for the optimal yield of crop plants. The required water level varies according to the variety of the crops. In the present study, we investigated the optimum requirement of groundwater level(GWL) to grow sorghum and adzuki bean under paddy field soil. Here, we cultivated sorghum and adzuki bean using lysimeter filled with paddy soil under GWL 0 cm(NT) and GWL(20, 40 cm) where GWL 20 cm is maintained as a waterlogging condition. The plant growth promoting attributes were measured on the first day after treatment(0 DAT), 10 DAT and 20 DAT. The results showed that the growth parameter such as shoot length, leaf length, leaf width, and stem thickness of both sorghum and adzuki bean were constantly increased and were found higher at GWL 40 cm(except stem thickness and leaf width in sorghum at 20 DAT). The physiological parameters such as chlorophyll content and stomatal conductance were also found higher at GWL 40 cm in all DAT. In addition, the elements like P and K contents in adzuki bean, and Ca content in sorghum were constantly increased and was found higher in GWL 40 cm at all DAT. These results suggest that the GWL of 40 cm is appropriate for production of sorghum and adzuki bean especially in case of paddy soil.

Petroleum energy is the major source of the world energy market, and its massive usage, and the corresponding extreme environmental pollution, imposes a serious threat on the ecological cycles. By screening oil-contaminated soil, we isolated, identified, and characterized a novel strain that represents a considerable diesel-degrading potentiality; the Bacillus aryabhattai DA2 strain is registered in the NCBI with the accession number MG571630, and it possesses an efficient tributyrin-degrading capacity. The optimal condition for diesel degradation by DA2 strain was observed at pH between 7-8 and at the temperature of 30°C. The strain is resistant to salt as well as the antibiotics like ampicillin and streptomycin. These results indicate B. aryabhattai is one of the potential candidates for the remediation of the diesel-contaminated sites.

The present study aimed to investigate the change in the morphological and physiological characteristics within sesame plant when subjected by regulating water levels. The experiment was conducted at ground water level(GWL) 0, 20, and 40 cm in a paddy field soil. The results showed that sesame growth characteristics, such as shoot length, stem thickness, leaf length, and leaf width were significantly higher in sesame at GWL 0 cm at 10 days after treatment(DAT) and 20 DAT than in those grown at a GWL of 40 cm. The shoot length and stem thickness of sesame grown at a GWL of 20 cm was significantly higher than those grown at a GWL of 40 at 10 DAT. The chlorophyll content was significantly lower in plants grown at a GWL 40 cm at 10 and 20 DAT over sesame grown in GWL of 0 and 20 cm. The stomatal conductance remained consistent in all the GWL at overall time period. Moreover, the Ca content of sesame was reduced in both GWL 40 cm and 20 cm at 10 DAT and 20 DAT as compared to GWL 0 cm. The K content was increased at 10 DAT but was reduced at 20 DAT at both GWL 20 cm and GWL 40 cm over plant grown at GWL 0 cm. Likewise, the P content was decreased at 10 DAT in both GWL 20 and GWL 40 cm but was significantly increased at 20 DAT in GWL 20 cm as compared to plant at GWL 0 cm. Since the experimental soil is paddy field soil these results helps to understand the efficiency of sesame to tolerate the different stress levels of soil moisture. Therefore, these research may help to predict the appropriate level of irrigation to be provided at different time period for the sesame if it is grown in rice field as a commercial crops.