Fungal endophytes representing diverse habitats and their role in plant protection

Abstract

Fungal endophytes are commonly considered all those highly diverse fungi that colonize internal tissue of plants either part or complete their life without causing any negative symptoms of disease. Researches on structural and functional diversity of fungal entophytes have developed great appreciation among the scientific community because its promises plethora of advantages to host plants which most of them we are not aware and to be potential source of novel metabolites that could serve as new drugs of pharmaceutical and agricultural importance. Endophytic fungi are reported from each group of plants from thallophytes to spermatophytes (algae to angiosperms) and from aquatic to xerophytic plants. Taxonomically they are categorized into two different phylogenetic groups i.e. clavicipitaceous and non-clavicipitaceous group that may be transmitted horizontally or vertically from plant to plant. Endophytism is classical example of mutualistic symbiosis which has evolved from the balanced antagonism between microbes and host plant during the course of time. Past researches on fungal endophyte mainly focused on diversity and its secondary metabolites; many aspects of their role in plant protection against biotic and abiotic stresses are less explored. Since the majority of these groups of microbes are mysterious and their other hidden potential values are yet to be discovered which need more attention. Past fragmentary reports on role of fungal endophyte in plant protection give enough clue regarding scope and application of these microbes as tools for the improving fitness of plant in terms of quality and quantity of their productivity. The present article mostly focuses to review the status on diversity of fungal endophytes in different groups of plants, and their spatio-temporal distribution including the role in plant protection.