Endophytes as a Source of High-Value Phytochemicals: Present Scenario and Future Outlook

Abstract

Endophytes, a group of microorganisms that reside within plants, are promising eco-friendly source of high-valued bioactive phytochemicals that are produced by their host. Some of the well-known examples of phytochemicals produced by endophytes are Taxol, camptothecin, azadirachtin, podophyllotoxin, vinca alkaloids, cinchona alkaloids rohitukine, and many others. The molecular machinery for production of phytochemicals in endophytes is likely acquired from the host plant. After growing in axenic conditions for a few generations, the endophyte generally undergoes attenuation, and the production of phytochemical may reduce to a great extent or stop completely. Genome sequencing of several endophytes revealed that complete biosynthetic pathways for production of phytochemicals may not be present or if present the genes may not be homologous to the plant genes. Other possible reasons for attenuation as well as experimental methods through which the issue of attenuation may be addressed have also been discussed in the chapter.