Endophytic fungi: understanding complex cross-talks

Abstract

Although heeding and leading in the application perspective, we are lagging to address the variegated cross-talks involved in plant-endophyte interactions, the basis for the pertinence of endophytes. Endophytism represents the phenomenon in which a microbe resides asymptomatically within the plant tissues. The competency of the endophytes to penetrate, colonize, and flourish inside the plant premises by exhibiting complex multivariate interactions with the host, makes them unique. An endophyte, besides dealing with the host has to deal with the existing endospheric microbiota to make its colonization successful. However, we are at the beginning to appreciate the involvement of complex crosstalks between a plant and its endophytic microbiome and among the endophytic microbes associated with the plant. In this review, conglomerate cross-talks existing between plants and endophytes to maintain an ecological balance has been emphasized. Endophytic fungi have developed a palette of strategies to make their subsistence asymptomatic within the host. However, it is still a concern of exploration to unravel all the strategies employed by the endophytes, especially at the molecular level to accomplish this complex cross-kingdom association and making an asymptomatic existence inside the host. In recent years, the bioprospection of endophytes has received much attention, however, the differential survival strategies developed by them are poorly understood. This review summarizes currently available knowledge about the mechanisms behind the endophytic fungal colonization emphasizing the strategies employed by them in maintaining endophytism with special reference to quorum sensing and quorum quenching.