Background Soil alkalization inhibits plant growth and yield, the endophytic plant growth-promoting bacteria (PGPB) can alleviate salt stresses for plant. Methods: Isolate a NaHCO3-tolerant Bacillus amyloliquefaciens strain (ZmBA DSM7), characterize its PGP traits, elucidate the physiological and biochemical mechanisms by which it enhances maize growth. Results: A ZmBA DSM7 strain was isolated from the root of maize growing in a mildly alkaline soil (pH 8.8). The strain exhibited high tolerance to 500 mM NaHCO3 and maintained its PGP traits, ZmBA DSM7 had a positive effect on maize seed germination and alkaline stress tolerance by enhancing seed vigor under normal or alkaline growth conditions. The maize seedlings inoculation with ZmBA DSM7 markedly improved chlorophyll content and reduced oxidative damage by lowering malondialdehyde (MDA) content and enhancing the antioxidant enzymes activities in the pots. In the field, ZmBA DSM7-inoculated plants showed a increase in yield (such as the ear length, the number of kernels row number, average spike weight, the 100-grain weight, and so on). Conclusion: The ZmBA DSM7 promotes maize growth and mitigates NaHCO3-induced alkaline stress in maize by a multifaceted mechanism involving enhanced nutrient acquisition (N, P and K) and antioxidant status and improved soil quality.
Li et al. (2025) studied this question.