Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: September 20, 2003
Publication Date: October 17, 2003
Citation: BASSETT, C.L., FARRELL, R., ARTLIP, T.S., WISNIEWSKI, M.E. TISSUE-SPECIFIC PROCESSING OF A PEACH (PRUNUS PERSICA L. BATSCH.) DEHYDRIN MRNA IN RIPE FRUIT MAY ALTER THE INTRACELLULAR DISTRIBUTION OF THE COGNATE POLYPEPTIDE. MEETING ABSTRACT. 2003. Technical Abstract: We have previously identified two dehydrin genes from peach (Prunus persica), Ppdhn1 and Ppdhn2. In plants the expression of dehydrins is generally associated with response to cold treatment or abscisic acid (i.e. water deficit). Whereas Ppdhn2 in peach bark tissues responds to water deficit, induction by cold temperatures is modest in comparison to Ppdhn1 expression, suggesting that its primary role might be associated more with water status than temperature sensing. To begin to understand how Ppdhn2 is regulated in response to abiotic stress, we determined and compared the transcription start site (TSS) for Ppdhn2 in July and January bark and in fully ripe peach fruit. Using RNA ligase-mediated 5' RACE (5' RLM-RACE), we identified a single predominant TSS for Ppdhn2 that was the same in both July and January bark tissue samples, suggesting that seasonal expression is controlled by the same set of transcription factors. 5' RLM-RACE analysis of RNA from ripe fruit indicated a TSS that was different from that of bark. This site is located approximately 200 bases upstream of the major bark TSS and is apparently driven by a different TATA box. A 142 b sequence flanked by GT and AG dinucleotides located downstream of the ripe fruit TSS is absent from 5' RLM-RACE products, indicating that this region of the sequence is recognized as an intron in fruit, but not bark. Conceptual translation of the putative mature transcript results in the addition of 34 amino acids to the N-terminus of PpDHN2. Several polypeptide sorting programs predict that the putative protein would be transported to mitochondria. This is the first report describing tissue-specific utilization of different TATA boxes within the same promoter and the first reported suggestion that a dehydrin might be located to mitochondria.