The 2011 ASHS Annual Conference

Temperature and water availability are significant factors driving the evolution of abiotic stress tolerance in plants through natural selection. Levels of both freezing and drought tolerance can vary widely between and within species. A common feature among studies of drought- and cold-induced gene expression has been an increase in the abundance of dehydrins, a sub-group of late-embryogenesis-abundant (LEA) genes. Using the recently released peach genome sequence, we have identified five ‘signature’ dehydrin genes and their promoters. While dehydrins encoded by PpDhn1-3 have been previously described, two additional deydrins in our study, PpDhn4 and PpDhn5, have not been previously characterized. Using the genome sequence data, we compared the amino acid sequence similarities of the conceptually translated protein products of this gene family, as well as similarities among the promoters of the individual genes. To identify which paralogs might be useful in breeding programs to improve cold hardiness, we assessed the expression of the dehydrin gene family in bark tissues sampled from five named cultivars in the winter and summer of 2010 (Clemson, SC). Results from qRT-PCR analysis indicated considerable diversity in dehydrin gene expression between cultivars and between different dehydrin paralogs.