Forest endophytes as a biological resource insights into their role in sustainable agriculture and agroforestry

Abstract Forest ecosystems are the hidden reservoir of beneficial microorganisms, particularly for endophytes, that colonize plant tissue internally without causing any disease symptoms and play a key role in plant health and ecosystem sustainability. Forest-derived endophytic bacteria and fungi are crucial in nutrient cycling, stress resistance and growth promotion via phosphorus solubilization, nitrogen fixation and synthesis of phytohormones. Those microbes allow plants to survive in low-nutrient and stressful environments. This review offers insights into the diversity, abundance, distribution, and functional characteristics of endophytes within forest environments over a diversity of host species and climatic zones. Through decomposition and transformation of organic matter, endophytic microbes contribute to soil fertility. Several functional genes facilitate this process, including nif H (involved in nitrogen fixation), pho D (associated with phosphate mobilization) and glc A (associated with organic acid synthesis). In addition to this, endophytes synthesize antioxidants and modify gene expression under varying environmental conditions, including high CO 2 , increased temperature, and nitrogen enrichment. Besides providing innate immunity against pathogens, they also stimulate the host’s defence mechanisms and synthesize antimicrobial compounds. Innovative, biotechnologies such as CRISPR/Cas9 and RNA interference offer to develop and improve the desired traits for targeted agroforestry and agriculture applications. In light of their multifunctional capabilities and ecological significance forest endophytes are an important biological resource that can be incorporated successfully in farming to increase crop yield, stress tolerance, and to minimize the application of chemical inputs.