Study of 2,5-dihydrochorismate, a newly discovered class of plant specialized metabolites.

ended

Plants produce arrays of specialized metabolites that are crucial for plant development, defense and interactions with the ever-changing environment. Discovery of metabolites and metabolic pathways by dissecting the underlying genetic basis is an important challenge, not only to increase our understanding of life, but also to provide indispensable applications for humans such as pharmaceuticals. In this project we will investigate the occurrence and biosynthesis of the 2,5-dihydrochorismates, a novel metabolic class that was recently discovered by the host group in the plant model Arabidopsis (unpublished). Notably, chemically synthesized 2,5-dihydrochorismate and analogues have been shown to be potent in vitro inhibitors of chorismate-utilizing enzymes. This inhibitory activity hints to a potential biological role for 2,5-dihydrochorismates in regulating the flux through these pathways, opening perspectives for applications. The direct objective of my project is to unravel the biosynthetic pathway of 2,5-dihydrochorismates. We therefore aim i) to structurally identify additional pathway intermediates and sinks via LC-MS based metabolite profiling and purification followed by NMR, ii) to test whether chorismate is a precursor of the pathway by feeding plants with Stable Isotope Labeled chorismate, followed by analyzing the MS fragmentation spectra of the labeled molecules, iii) to investigate the role of an operon-like gene cluster involved in the biosynthesis of 2,5-dihydrochorismates via reversed genetics, and iv) to obtain insight in the in planta role of 2,5-dihydrochorismate by feeding experiment followed by metabolic profiling. My experience in reversed genetics and enzyme kinetics in specialized metabolism in rice make me well suited to bring this project to success. My prime objective is to strengthen my skills in metabolite profiling, pathway discovery and structural elucidation, to become an independent plant scientist in plant specialized metabolism.