Enhanced Salinity Tolerance of Medicago sativa, Roots AM Colonization and Soil Enzyme Activities by PGPR

Abstract

Abiotic stresses such as salt are typical negative factors that have a considerable impact on agricultural output around the world. The goal of this study was to investigate the effect of halotolerant plant-growth-promoting rhizobacteria (PGPR) on plant growth and soil function under salinity stress. The consortium of four PGPR (Pseudomonas putida, Alcaligenes sp., Klebsiella sp., and Pseudomonas cedrina) was tested for its effect on growth, chlorophyll content, oxidative stress, and root arbuscular mycorrhizal (AM) colonization of Medicago sativa in pots experiment under salt stress. The bacteria’s impact on soil enzyme activity was also investigated. Overall, in comparison to the non-inoculated control, inoculating M. sativa plants with the bacterial consortium allowed us to overcome the unfavorable effects of NaCl stress and enhanced plant growth, root AM colonization, and leaf chlorophyll content. It also reduced the levels of oxidative damage indicators such as malondialdehyde, hydrogen peroxide, and proline. Furthermore, the consortium had a beneficial effect on the activities of soil phosphatase, β-galactosidase, and arylamidase. The bacterial consortium has the potential to be employed as bio-inoculants for plants growing under salt stress.