Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 2004
Publication Date: N/A
Technical Abstract: Living cells respond to environmental stresses by up-regulating specific subsets of genes while down-regulating others. Global approaches to identifying these different groups of genes have been successfully applied to several plant systems. However, certain limitations restrict the degree to which each approach is successful in documenting differences in expression. For example, microarray analysis is restricted to previously isolated genes and does not allow identification of unique, undiscovered genes that might be crucial to the response being studied. EST library approaches overcome this problem, but are labor intensive and target for the most part genes that are moderately-to-highly abundant. One approach that overcomes these limitations is the synthesis of gene libraries after subtractive hybridization. By subtracting cDNAs synthesized from RNAs expressed in one state from cDNAs derived from RNAs expressed in another state, one can obtain sequences up-regulated in the first state relative to the second, since sequences in common are removed by hybridization. By varying which cDNA serves as the driver of the hybridization reaction, one can obtain both up-regulated (forward subtraction) and down-regulated (reverse subtraction) in response to a given condition. In an effort to profile gene expression at different temperatures under different photoperiods, we have created subtracted libraries from peach (Prunus persica) bark tissues sampled from trees kept at 5ºC and 25ºC under a short day (SD) photoperiod or exposed to a night break (NB) interruption during the dark period of the SD cycle. Sequences expressed in forward and reverse subtractions using various subtracted combinations of temperature and photoperiod treatments were cloned, sequenced, and identified by BLAST analysis. The results will be discussed relative to known or predicted functions of the gene products identified and their association with the various treatments analyzed.