Metabolomics of drought stress tolerance in plants

Abstract

Metabolites are more closer to the phenotype of an organism than the gene or protein component, as it takes into account the environmental interaction. It is ultimately the condition of the environment, which determines the actual potential of expression of a trait. Drought stress is one of the most important sought after problems in the context of climate change, the arid and semi-arid zones being extremely vulnerable. There is serial changes in the physiological process and accumulation of different metabolites within a plant after receive of stimuli. There is severe reduction in carbon dioxide assimilation rate associated with stomatal closure under drought stress. There is also over-production of ascorbic acid, glutathione, several amino acids including leucine, isoleucine, valine, proline etc. and polyphenols. These compounds serve as antioxidant machinery against the oxidative stress caused due to drought. There is also accumulation of carbohydrates and their alcohols in response to water stress. ABA plays a key role in drought stress signaling pathway. Hence, the characterstic metabolite markers can be used to trace out tolerant genotypes or rootstocks to wide range of abiotic stresses. GC-MS and NMR techniques are used as aid for metabolite profiling, which helps in identification and quantification of all low molecular weight molecules in a plant system. Therefore, metabolomics can be a promising approach to over-ride the constraints of achieving higher productivity due to stress factors.