ASGSB 2003 Annual Meeting Abstracts


REGULATION OF RAPID, TRANSIENT GENE EXPRESSION DURING GRAVITROPIC STIMULATION IN ARABIDOPSIS.  J. M. Kimbrough, R. Salinas-Mondragon, C.S. Brown, and H. Winter Sederoff NSCORT, Dept. Botany, NC State University, Raleigh.

   Gravity-specific transcriptional regulation occurs within less than 2 min in an Arabidopsis root tip. Microarray analysis revealed several “very early transcripts” that comprise a group of genes coding for proteins functioning in the transcriptional and translational machinery (transcription factors, ribosomal RNA, RNA binding proteins, DNA binding proteins), some predicted (hypothetical) proteins and proteins with unkown function, as well as some proteins predicted to be involved in signal transduction and transcription. Steady-state mRNA levels reflect the relative rates of synthesis versus degradation of these specific transcripts. Several of these very early transcripts were “up-regulated” and several were “down-regulated”.  Increased rates of transcription are usually brought about by specific promoter elements, while 3’ and 5’ untranslated regions (UTRs) are known to be involved in transcript stability. We have analyzed the promoter sequences and UTRs of those transiently regulated gravitropically regulated genes for known sequence elements and generated new motifs possibly involved in the transient nature of the early gravitropic genes.

(Supported by NASA: NAG2-1566)


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