MORPHOLOGICAL ALTERATIONS AND GENE EXPRESSION IN A SET OF SUGARCANE VARIETIES UNDER WATERLOGGED CONDITIONS

Present study was aimed to investigate the morphological response and expression pattern of PFP (Pyrophosphate -dependent fructose-6-phosphate 1-phosphotransferase), CYP81D8 (Cytochrome P450 gene), P5Cs (Pyrroline-5-carboxylate synthetase) and SOD (Superoxide dismutase) genes of sugarcane plants maintained under waterlogged conditions. Waterlogged and control plants of four sugarcane varieties, CoLk 94184, BO 91, CoS 767 and CoJ 64 were used for morphological studies and leaf tissues for RNA isolation and gene expression analysis. Obtained results indicated higher plant height of waterlogged plants, while, leaf area and SPAD index decreased markedly as compared to control. The earlier appearance of aerial rooting seems to be associated with greater shoot root injuries due to waterlogging. Degree Brix (°Brix) in cane juice was relatively higher in most of studied varieties except BO 91 due to waterlogging; variety CoLk 94184 showed highest increase (66.7%) over control. In leaves, the transcript of PFP enzyme (phospho fructokinase) which is involved in glycolytic reactions was up-regulated in two varieties (90.5% in CoLk 94184), (2.9% BO 91) but down-regulated in others. In waterlogged plants, CYP81D8 (ROS related proteins) gene showed relevant increase (+110% in CoLk 94184) and BO 91 (13.6%) but slightly decrease in CoS 767 (-7.7%,) and CoJ 64 (-5%). P5CS involved in proline biosynthesis is slightly increased under waterlogged conditions. SOD, an antioxidant enzyme increased significantly due to waterlogging; highest increase (+154%) was observed in CoLk 94184 variety. Expression analysis of these genes exhibited strong correlation with shoot and leaf attributes.