GENE DISCOVERY: APPROACHES, DEVELOPMENTS AND APPLICATIONS TO SUGARCANE IMPROVEMENT

Knowledge of the identity of genes participating in the delivery of important traits or displaying tissue- or organ-specific expression is advantageous in the development of rational molecular breeding strategies. Over the past 15 years, the South African Sugarcane Research Institute (SASRI) has enjoyed considerable success in the discovery of such genes, which have been used within marker-assisted breeding and genetic engineering strategies. For example, identified genes have facilitated the development of genetic markers depicting resistance or susceptibility to the stalk borer, Eldana saccharina, as well as in the modification of the activity of enzymes involved in sucrose metabolism. Over the years, several technologies have been used at SASRI for gene discovery, including Expressed Sequence Tag Analysis, cDNA Differential Display, Suppression Subtractive Hybridisation and Affymetrix ® Sugarcane Genome GeneChip analysis. While the application of these technologies has been successful, the recent advent of the next-generation DNA sequencing and gene expression analysis technologies and the release of the Sorghum genome sequence herald a new era for gene discovery in sugarcane; one which presents SASRI scientists with new challenges and opportunities. Presented here is an overview of gene discovery strategies employed at SASRI and the impact that they have had on sugarcane improvement research. Also described is the manner in which recent technological and bioinformatical advances are being embraced within this area of research.