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.
Key
words:
Drought, Erianthus arundinaceus, Germplasm, Metabolomics, Sugarcane
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