RESUMO
The study is aimed to assess the morphological, physiological, and molecular responses of seven Saccharum spontaneum clones for salinity stress. These clones (IND-07-1462, IND-07-1465, IND-07-1470, IND-07-1471, IND 16-1761, IND 16-1762, and IND 16-1763) were subjected to salinity stress at two different concentrations of electrical conductivity 6 and 8 ds/m after 60 days of planting. All seven genotypes showed a decrease in relative water content and nitrate reductase activity with an increase in severity of salt stress. The effect was more pronounced in IND-07-1471, while IND-16-1762 exhibited only a minimum drop. Similarly we observed an increase in proline content and lipid peroxidation activity for the genotype IND-07-1471, while IND-16-1762 showed minimum increase. Molecular profiling of genes/transcription factors like salt overly sensitive, responsive to abscissic acid, dirigent, myeloblastosis, ethylene responsive factor associated with salinity stress tolerance showed 19-, 18-, 17-, 10-, and 9-fold increased expression at 8 ds/m of salinity stress, respectively, in IND-16-1762 showed. Based on the evidences obtained from expression profiling, we have cloned the conserved regions of RAB and SOS1 genes. The domain of SOS and RAB was identified as a regulatory subunit of cAMP-dependent protein kinases which is involved in a signaling pathway.