Treatments with native Coleus forskohlii endophytes improve fitness and secondary metabolite production of some medicinal and aromatic plants.

Abstract

Endophytes have been shown to play a crucial role in determining the fitness of host plant during their association, yet the cross-functional effect of endophytes of one plant on another plant remains largely uncharacterized. In this study, we attempt to analyze the effect of native endophytes of Coleus forskohlii (Phialemoniopsis cornearis (SF1), Macrophomina pseudophaseolina (SF2), and Fusarium redolens (RF1), isolated from stem and root parts) on plant growth and secondary metabolite enhancement in medicinal plant Andrographis paniculata, and aromatic plants Pelargonium graveolens and Artemisia pallens. Here, we report, endophytic treatments with SF2 (21%) and RF1 (9%) in A. paniculata resulted in significant enhancement of andrographolide along with plant primary productivity. Correspondingly, application of fungal endophytes RF1, SF1, and SF2 significantly improved the plant growth (11 to 40%), shoot weight (28 to 34%), oil content (44 to 58%), and oil yield (72 to 122%) in P. graveolens. Interestingly, treatment of A. pallens with three fungal endophytes resulted in significant enhancement of plant productivity and oil content (12 to 80%) and oil yield (32 to 139%). Subsequently, the endophyte treatments RF1 and SF1 enhanced davanone (13 to 22%) and ethyl cinnamate (11 to 22%) content. However, SF2 endophyte-treated plants did not show any improvement in ethyl cinnamate content but enhanced the content of davanone (10%), a signature component of davana essential oil. Overall, results depict cross-functional role of native endophytes of C. forskohlii and repurposing of functional endophytes for sustainable cultivation of economically important medicinal and aromatic crops.