Sugarcane specific drought responsive candidate genes identified through differential expression in resistant and susceptible genotypes of sugarcane (Saccharum sp.)
Simon, S.; Hemaprabha, G.
International Sugar Journal 114(1366): 731-737
ISSN/ISBN: 0020-8841 Accession: 066266236
In this study, drought resistant and susceptible progenies from a mapping population involving a resistant genotype (Co 740) with a susceptible one (Co 775) were subjected to drought during the formative phase of growth and differential expression of seventeen drought responsive candidate genes were studied through RT-PCR analysis. Specific upregulation of ten genes in the resistant clones indicated their role in drought resistance in sugarcane. These were genes responding to drought through abscisic acid (ABA) independent, auxin dependent pathway viz. (Indole-3-glycerol-phosphate synthase (IGS) and Polar auxin transport gene (PIN 1), ABA independent dehydration responsive element binding proteins (DREB), genes involved in plant defense through antioxidant enzyme activity viz. Superoxide dismutase (SOD), Dehydroascorbate reductase (DHAR), Cytosolic ascorbate peroxidase (cAPX), Glutathione-S-transferases (GST 1) and Glutathione synthase 1 (GSHS1), genes encoding drought protein kinase (Prokin) and ABA dependent late embryogenesis abundant proteins (LEA 3). The importance of root characteristics in drought tolerance was revealed by the expression of six auxin responsive genes (IGS, NIT 1 NIT 2 NIT 3, PIN 1, PIN 3, ILL 1 & ILL 2 and GAPDH). These differentially expressed genes can serve as markers in screening breeding populations and exploring the possibility of MAS in the genetically complex crop of sugarcane to achieve genetic improvement for drought resistance at a faster rate.