Comparative profiling of drought induced root metabolic responses in sugarcane wild relative Erianthus arundinaceus (IND 04-1335) and a commercial variety Co 99004

Abstract

Aim: To study the metabolic changes in roots of a drought tolerant wild relative of sugarcane Erianthus arundinaceus clone (IND 04-1335) and a commercial sugarcane cultivar Co 99004. Methodology: Setts of Erianthus arundinaceus (IND 04-1335) and a commercial variety Co 99004 were planted in medium size pots in replication. After 45 days of planting, drought stress was imposed by withholding irrigation. The corresponding control pots were maintained under continuous irrigation. On 26th day of drought, stress morphological and physiological traits such as leaf drying, canopy temperature, leaf relative water content and chlorophyll fluorescence were recorded. Root samples were subjected to metabolomic analysis using GC-MS. Results: After 26 days of drought exposure, IND 04-1335 were found to be tolerant without any drought induced morphological symptoms. The comparative metabolite profiling identified a total of 143 metabolites in the control and drought exposed roots. Hierarchical cluster analysis showed that roots of IND04-1335 control and Co 99004 stress had the most similar metabolite profiles, while the profile of IND04-1335 stressed root was distinctive.The metabolomic profile of IND04-1335 under drought stress showed an increased accumulation of sugars (melezitose, trehalose), sugar alcohols (mannitol), amino acid (proline) and carotenoids (rhodopin, carotene) as compared to Co 99004. Interpretation: Differentially accumulated metabolites in IND04-1335 under drought stress may play an important role as osmoregulants, antioxidants and chelating agents thereby imparting better tolerance mechanism to this genotype.