Abstract

Endophyte refers to the endosymbiotic microorganisms that reside asymptomatically in plant tissues. They aid in plant growth promotion and disease resistance. Most plant species have endophytic associations and their functions are now well documented. These microorganisms help plants take up nutrients, stimulate the production of phytohormones, and fix atmospheric nitrogen. This makes plants more tolerant against biotic and abiotic stress. They are natural rivals of plant pathogens since they produce anti-microbial metabolites, compete for nutrients and space, and induce systemic resistance in their host plants. The use of endophytes in agriculture can be an environment friendly alternative to chemical fertilizers and pesticides for the long-term protection of crops. By investigating the diversity and functional traits of beneficial microorganisms, novel bio-stimulants, bio-inoculants, and biocontrol agents can be developed. Despite the advantages, endophytes have certain limitations, such as host specificity, environmental variability, and inconsistent colonization, often failing to perform reliably under field conditions. Competition with native microbiota, safety concerns, and commercialization challenges further restrict their widespread application. The review highlights the natural diversity, antagonistic mechanism toward pathogens, and potential agricultural applications of endophytes, which has immense potential toward agro-ecosystem sustainability and resilience.

Key words: Abiotic stress, Biotic stress, Crop protection, Endophytic diversity, Plant health, Sustainable agriculture