The objective of our work is to increase fundamental knowledge of plant metabolism in order to obtain, through metabolic engineering, plants with added nutritional value or better adapted to environmental stresses, including to the climate change. For this purpose, we combine metabolomic, bioinformatic, proteomic and genomic approaches. Our work has focused on the study of several routes of primary metabolism (glycolysis, and serine biosynthesis) and secondary metabolism (glucisinolate biosynthesis).
At present our study focuses on serine metabolism. Plants possess several pathways of serine biosynthesis. Our group has functionally characterized for the first time in plants one of them, the so called phosphorylated pathway. This pathway had been considered of little importance in plants, but we have shown that it is essential for plant development. Serine is also essential for sulfur metabolism, and some metabolites crucial for plant response to biotic and abiotic stresses contain sulfur [glutathione, phytochelatins, glucosinolates (GSL)] or require organic sulfur [abscisic acid] in their biosynthetic processes. We are studying the basic mechanisms connecting serine biosynthetic pathways to secondary metabolism, and how metabolic reprogramming of serine-dependent pathways can help plants tolerate biotic (defense against pathogens) and abiotic (salt, drought, heavy metals) stresses, especially under conditions of climate change (high CO2 levels and temperatures).
One of the mechanisms of plant tolerance to stresses mediated by serine could involve GSLs, which are serine derivatives abundant in species of the Brassicaceae family. These GSLs have a role in the defense against insect and pathogen attack. In addition, GSLs do not have harmful effects on human health, but have been described to possess anticarcinogenic properties. In this regard, isothiocyanates (bioactive derivatives of GSLs) are considered to be the phytonutrients responsible for the anti-cancer properties of brassicas (broccoli, Brussels sprouts, cauliflower). There are more than 200 types of GSLs, and only a few of them have been studied for their anti-pathogenic, anti-insecticidal or anti-carcinogenic capacity. Our group is deepening the study of the relationship between specific GSLs and tolerance to biotic stresses.
The model plant Arabidopsis thaliana is used as a proof-of-concept approach for many of our studies, but these studies also extend to maize, a species of agronomic interest and Brassica oleracea genotypes, selected for their high level of GSLs and/or agronomic interest.
