Exploring the Functional Roles of Endophytic Bacteria in Plant Stress Tolerance for Sustainable Agriculture: Diversity, Mechanisms, Applications, and Challenges

Endophytic bacteria, which reside within plant tissues without causing harm, play crucial roles in promoting plant health and enhancing tolerance to biotic and abiotic stresses, making them highly valuable for sustainable agriculture. This review explores the diversity, mechanisms, applications, and challenges associated with endophytic bacteria in enhancing stress tolerance in plants. Endophytic bacteria display extensive diversity, spanning multiple phyla such as Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria, each contributing uniquely to plant growth and stress tolerance. The functional mechanisms by which endophytic bacteria promote stress tolerance against biotic and abiotic stresses include the induction of plant systemic resistance, synthesis of bioactive compounds, competition for space and resources, nutrient production and transfer, etc. Despite their great potentials, challenges such as the complexity of plant-microbe interactions, variability in bacterial efficacy across different environmental conditions, and the need for advanced identification and application techniques hinder the widespread application of endophytic bacteria in agriculture. This review underscores the importance of harnessing the great potential of endophytic bacteria for developing sustainable agricultural practices and highlights the urgent need for further research to overcome existing challenges.