Root-Associated Plant Growth-Promoting Bacteria in Mangrove Ecosystem and its Application in Sustainable Biotechnology

Abstract

Mangroves are distinguished as a unique ecotone, characterized by their specialized habitat and extreme environmental conditions, including high salinity, tidal fluctuations, elevated temperatures, low oxygen levels, and waterlogging. While these stressors impose numerous challenges on mangroves, the plants have evolved adaptive mechanisms to cope with such harsh conditions. Crucially, the root-associated microbial community, particularly plant growth-promoting bacteria (PGPB), plays an essential role in aiding mangrove plants to withstand these adverse conditions, highlighting the symbiotic relationship vital for mangrove resilience. The study aims to explore the root-associated PGPB in mangrove ecosystems, focusing on their roles and potential biotechnological applications. It has been found that these diverse PGPB, isolated from mangroves, exhibited plant growth-promoting properties, including nitrogen fixation, solubilization of phosphorus and potassium, and the production of beneficial compounds such as phytohormones, exopolysaccharides, and volatile organic compounds. These traits of PGPB contribute not only to plant growth and development but also to resilience against various stresses, especially salinity. They aid in maintaining nutrient and ionic balance, modulating hormonal levels, providing osmoprotection, mitigating oxidative stress, and enhancing resistance to pathogens within the mangrove ecosystem. Moreover, the study highlights the promising biotechnological applications of these microbes in promoting sustainable agricultural practices in saline environments, enhancing environmental remediation efforts, and supporting mangrove reforestation initiatives. In conclusion, leveraging the symbiotic relationships between mangrove plants and their root-associated PGPB offers innovative, sustainable solutions to contemporary environmental challenges, paving the way for enhanced ecosystem resilience and productivity.

Keywords: Halotolerant; Mangrove; Plant growth-promoting bacteria; Rhizosphere; Saline based agriculture.