Endophytic consortium with growth-promoting and alkaloid enhancing capabilities enhance key terpenoid indole alkaloids of Catharanthus roseus in the winter and summer seasons

Abstract

Catharanthus roseus produces medicinally important terpenoid indole alkaloids (TIAs) such as vindoline, vinblastine, and vincristine, but in very small amounts. The various microbial consortium consisting of plant growth-promoting and alkaloid enhancing endophytes were developed in order to enhance the overall productivity of such pharmaceutically important alkaloids. Furthermore, we attempted to identify the endophytic consortia suitable to maximally improve the content and yield of TIAs in field-grown C. roseus cultivars during the winter and summer seasons. The consortium, CATDLF5 + CATPS2 (Curvularia sp.+Bacillus pumilis), improves leaf weight in all C. roseus cultivars during winter and summer. On the alkaloids front, the consortium, CATDLF5 + CATPS2, maximally enhanced the vindoline content and yield in C. roseus cvs. Prabal and Nirmal during both winter and summer seasons; but different consortia were effective for improving vindoline content and yield in cv. Dhawal during different seasons. Whereas co-inoculation of CATDLF6 + CATPR13 (Choanephora infundibulifera + Paenibacillus sp.) and CATDLF5 + CATPS2 consortium maximally enhanced vindoline content and yield, respectively, in C. roseus cv. Dhawal during winter; but during summer, CATDLF6 + V3 (Choanephora infundibulifera + Micrococcus sp.) maximally increased both vindoline content and yield in C. roseus cv. Dhawal. The presence of vincristine and vinblastine are maximally detected in C. roseus plants during summer season. The consortium of CATDLF5 + CATPR13 (Curvularia sp. + Paenibacillus sp.) maximally enhanced the content as well as yield of vincristine and vinblastine in C. roseus cvs. Prabal and Nirmal plants, while CATDLF6 + CATPR13 inoculation showed maximal improvement in the content and yield of vinblastine and vincristine in C. roseus cv. Dhawal plants. This study identifies the best combination of endophytes that can maximize the plant growth and TIAs yield in various C. roseus plant cultivars under field conditions for both winter and summer seasons.