Seed priming with plant growth-promoting rhizobacteria alleviate salinity stress in wheat plant

The objective of this paper was to study the effects of two strains of isolated plant growth-promoting rhizobacteria (PGPR) on physiological and biochemical changes of wheat leaves under salinity conditions. The sterilized seeds were soaked in distilled water (control) and Nutrient Broth liquid medium of Enterobacter cloacae and Bacillus cereus (inoculated treatment) for 2 hours. After 10 days of growth, seedlings were selected for salinity stress treatments (0, 100, and 200 mM NaCl). After 10 days of starting salinity treatments, plants were harvested. Results showed that wheat plant growth, chlorophyll content and catalase activity were reduced under salinity condition; however, PGPRs pre-treatments improved them under stress condition. Salinity significantly increased phenolic, carotenoids, proline and sugars content and peroxidase activity. Moreover, inoculation of seeds by PGPRs increased them under salinity. Lipid peroxidation increased but ascorbate peroxidase activity decreased as a response of saline stress and PGPRs pretreatment of seeds reduced them. Salinity increased sodium content, and PGPRs pretreatments decreased sodium absorption under salt stress. Moreover, in this study, Enterobacter cloacae inoculation of seeds increased wheat plants magnesium and potassium content in control condition as well as under salt stress. Data of experiment showed that the priming with PGPRs which tested in the present study especially E. cloacae can promote plant growth and salt tolerance.