Sachin Pratap Tomar, P. Smriti Rao, Shailendra Kumar Singh, Shishir Kant Singh, Khalid Habib, Saba Siddiqui, Mohammed Haris Siddiqui and Ambreesh Singh Yadav
Abstract
This review aims to synthesize current knowledge on the mechanisms, roles, and identification methods of halophilic plant growth-promoting rhizobacteria (PGPR) to highlight their promising role in promoting sustainable agriculture, especially in salt-affected regions, and to address the critical threat of soil salinity to global agriculture. This review systematically synthesizes existing literature on halophilic and halotolerant PGPR, focusing on their potential to enhance plant resilience under saline conditions. It explores the various mechanisms employed by these microorganisms for plant growth promotion and their adaptation strategies in high-salt environments. Additionally, it covers advanced characterization techniques used for their identification and classification. Halophilic and halotolerant PGPR demonstrate significant potential in mitigating salinity-induced stress by contributing to plant growth through mechanisms such as phytohormone production, phosphate solubilization, ACC deaminase activity, antioxidant enzyme induction, and siderophore synthesis. These microbes adapt to high-salt environments via strategies like salt-in, compatible solute accumulation, and exopolysaccharide production. Advanced phenotypic profiling, molecular, and chemotaxonomic analyses aid in their accurate identification and classification.