Enhancement of salt tolerance in maize (Zea mays L.) using locally isolated Bacillus sp. SR-2-1/1

The current study was aimed at enhancement of salt tolerance of maize by using a halotolerant plant growth promoting rhizobacterium. Maize seeds (FH-1137) were grown under salt stress with and without inoculation of a locally isolated Bacillus sp. SR-2-1/1. Inoculation of Bacillus sp. SR-2-1/1 significantly augmented the salt tolerance of maize plants which was reflected by increased contents of chlorophyll, total phenolics and proline. Moreover, inoculation of strain SR-2-1/1 resulted in less oxidative damage in terms of H₂O₂ production and lipid peroxidation. This was further supported by higher catalase and peroxidase production in these plants. Bacillus sp. SR-2-1/1 exhibited positive effects on the expression of photosynthesis (RBCL), antioxidants status (CAT1, APX1, APX2) and plant ion homeostasis (NHX1, SOS1, H⁺-PPase, and HKT1) related genes. To the best of our knowledge, this is the first study reporting enhancement of salt tolerance in maize genotype FH-1137 by using plant growth promoting rhizobacterium. The use of Bacillus sp. SR-2-1/1 as bio-inoculant seems to be a sustainable alternative to alleviate salt-induced damages in maize. This approach can be applied to other plant species to increase salt tolerance.