Role of Plant Growth-Promoting Rhizobacteria in Enhancing Rice Yield Under Salinity Stress in China

Abstract

Soil salinity is a major abiotic stress that severely affects rice production, especially in coastal areas of China. This study explores the role of plant growth-promoting rhizobacteria (PGPR) in mitigating the adverse effects of salinity stress on rice plants. A collection of 15 PGPR strains isolated from salt-affected soils was evaluated for their ability to promote plant growth and enhance salt tolerance in rice. Through greenhouse and field trials, we observed significant improvements in rice growth, including enhanced root development, shoot elongation, and chlorophyll content, following PGPR inoculation. The most effective strains included Bacillus subtilis, Pseudomonas fluorescens, and Azospirillum brasilense, which helped alleviate the negative impacts of high salinity by promoting nutrient uptake, increasing antioxidant activity, and modulating plant hormonal balance. Metagenomic analysis of the rhizosphere microbiome indicated that PGPR inoculation led to an increase in beneficial bacteria associated with nutrient cycling and stress tolerance. The study also demonstrated that PGPR inoculation reduced soil salinity and improved microbial diversity. These findings offer a sustainable solution for enhancing rice yield in salinity-affected areas and contribute to the development of microbial inoculants for agriculture.