Submitted to: American Society of Sugar Cane Technologists
Publication Type: Abstract Only
Publication Acceptance Date: May 22, 2009
Publication Date: July 1, 2009
Citation: Edme, S.J., Glaz, B.S. 2009. AN ASSESSMENT OF COLD/FREEZE TOLERANCE IN SUGARCANE. American Society of Sugar Cane Technologists. Volume 29:86 Technical Abstract: The complexity of tolerance mechanisms of crops to environmental stresses requires a multipronged approach to decipher the genetics of and breed for stress resistance. Field tests and a proteomics analysis were carried out on sugarcane genotypes to assess the time-course deterioration of sucrose in the juice after freeze events and to identify the proteins or genes that confer tolerance. The field trials were conducted in 2007-2009 in Florida at Hague, Alachua (latitude: 29o45’0”N/longitude: 82o25’48”W) and at Canal Point, Palm Beach (latitude: 26o51’50”N/longitude: 80o37’32”W) to obtain the sucrose profiles of 15 sugarcane (Saccharum spp.) genotypes in the final stage of selection in the Canal Point breeding program (CP03 Series) along with three reference cultivars. Freezes occurred in both years at Hague and in the second year at Canal Point. Repeated measures analyses were used to model the covariance structures of the data and to discriminate the genotypes in terms of tolerance or susceptibility by way of different stress indices. The proteins of two genotypes (CP 65-357 and SES 234) were extracted and sequenced to capture the nature of their differential response to cold/freeze temperatures. Specific proteins associated with cold or abiotic stress in plants were identified, such as dehydrins, heat shock proteins, and pyruvate phosphate dikinase. Proteins that are known to be associated with specific metabolic processes (PPDK, CYP450), transport (ABC transporter, proteasome complex), photosynthesis (ATP synthase F0), and protein protection and destruction (HSP, proteasome complex) were detected at dissimilar levels in the two genotypes and used to construct and link the different pathways (TCA cycle, water-water cycle, xantophyll cycle) involved in cold stress in sugarcane.