Identification and Characterization of Transcripts Associated with Tolerance to Drought and Flooding Stress in Sugarcane

Flooding and drought tolerance are desirable breeding characteristics for Colombian sugarcane cultivars due to the high cost of irrigation and drainage systems. Previous works on the characterization of varieties with high water use efficiency led to the identification in our germplasm collection of varieties CC 93-7711 and SP 71-6949 as tolerant and MZC 74-275 as sensitive in the case of drought. Varieties CC 01-1940 and CC 93-4418 were respectively identified as tolerant and sensitive in the case of flooding. With this information, a comparative transcriptomics study began as an attempt to identify genes responsive to the characteristics of interest.  To date, 24 leaf-cDNA libraries from the five genotypes mentioned above, under well-irrigated or mild and severe stress conditions (drought or flooding), have been sequenced using Illumina technology. Preliminary data allowed to identify >100 genes that appear up or down regulated uniquely in the tolerant varieties, for each specific treatment, and that hold potential for further characterization. Also, >1,000 SSR and SNP sequences have been identified which will be further analyzed for their potential to be used in genotyping studies.

The final goal of this investigation is to contribute in the development of breeding strategies supported by molecular markers and, when appropriate, on plant transformation to obtain varieties highly efficient in the use of water.