Biochemical fingerprinting of endophytes harbored in Radula marginata that confer plant fitness benefits

Our work focusses on the assessment and elucidation of the cost-benefit interactions of a special group of microorganisms known as endophytes which inhabit the internal tissues of the host plants without causing any immediate negative effect, and remain in a mutualistic association for at least a part of their life cycle. Plants are known to produce various bioactive secondary metabolites as defensive compounds. Cannabinoids are the most extensively studied secondary metabolites of Cannabis sativa L. plants. Recent work on liverworts like Radula marginata led to the identification of new cannabinoids with structural similarity to tetrahydrocannabinol, the major psychoactive compound of Cannabis plants. We have isolated a plethora of endophytes, both fungi and bacteria, from R. marginata. Since both Radula and Cannabis contain similar biosynthetic principles, we are evaluating the biocontrol potential of the endophytes against the host specific phytopathogens of C. sativa L. plants namely, Botrytis cinerea (causing gray mold disease) and Trichothecium roseum (causing pink rot disease), respectively.

We are investigating the various attack-defense-counterdefense responses of the isolated endophytes when challenged by the phytopathogens. These responses trigger the production of secondary metabolites or intermediates which are otherwise 'cryptic'. We are not only analyzing the various cost-benefit tradeoffs between the endophytes and host plants but also evaluating the bioactive target and/or non-target metabolite production correlating to the endophyte-pathogen interactions. This will enable us in understanding the biochemical fingerprint of the endophytes which aid in thwarting the phytopathogens and reducing the loss of such therapeutically beneficial plants.

References:

[1] Kusari et al. (2012) Fungal Divers In Press (doi. 10.1007/s13225 – 012 – 0216 – 3)

[2] Kusari et al. (2013) In: Kharwar R.N. (ed.) Endophytes, (ICPMB 2012), Springer-Verlag, Heidelberg. In Press