Untapped mutualistic paradigms linking host plant and endophytic fungal production of similar bioactive secondary metabolites

Highlighted are poorly investigated interactions that endophytes have with host plants, insect herbivores and with each other, and the diverse molecular mechanisms that might trigger similar chemical responses in both plants and endophytes. Elucidating such networks can enhance discovery of desirable endophytes and further sustain production of host plant compounds using the isolated endophytes. [Display omitted] ► Plants and endophytic fungi can occasionally produce similar bioactive compounds. ► Endophytes interact with coexisting endophytes, host plant, and insect herbivores. ► Early signaling mechanism influencing such endophyte interactions should be studied. ► Elucidating the molecular basis of such multifaceted interactions is also important. ► These distinct interactions can trigger similar chemical responses in the partners. The biosynthetic potential of endophytic fungi has gained impetus in recent times owing to the continual discovery of fungal endophytes capable of synthesizing plant compounds. However, the sustained production of the desired plant compounds has not yet been achieved using endophytes. It is thus imperative to investigate the diverse interactions that endophytes have with coexisting endophytes, host plants, insect pests, and other specific herbivores. The precise role of these associations on the endophytic production of host plant compounds is mostly overlooked and open to future discoveries. Here, highlighted are the implications of the poorly investigated links and molecular mechanisms that might trigger similar chemical responses in both plants and endophytes. Elucidating such connections can not only enhance the understanding of evolution of complex defense mechanisms in plants and associated organisms, but also help in the sustained production of plant compounds using endophytes harbored within them.