Submitted to: Annual International Meeting for Moss Research
Publication Type: Abstract Only
Publication Acceptance Date: 9/7/2003
Publication Date: 9/10/2003
Citation: Oliver, M.J., Hudgeons, J., Dowd, S.E., Mauget, S.A., Payton, P.R. 2003. Tortula est database and its use in the microarray analysis of gene expression during desiccation and rehydration[abstract]. Annual International Meeting for Moss Research.
Technical Abstract: Gene expression studies of desiccation-tolerant plants are limited to only a few species, one of which is the desiccation-tolerant moss Tortula ruralis. From an evolutionary standpoint, T. ruralis represents the primitive mechanism for tolerance of dehydration and thus an understanding of its genome level response has important implications for plant biology and agriculture. We have demonstrated that the alteration in gene expression in response to desiccation in this plant occurs following rehydration, in large part, as the result of a change in translational controls. In addition, during drying certain transcripts, encoding rehydrins are sequestered in messenger ribonucleoprotein particles (mRNPs) for storage in the dried state. To determine the extent and importance of translational versus transcriptional events, we have taken two approaches. We have established an EST collection, consisting of 10,000 cDNA clones, from a rehydration specific library and have constructed rehydration and drying specific Subtractive Suppression Hybridization (SSH) cDNA collections. ESTs were processed for quality, vector contamination removed, and contiging performed using SeqMan (DNAstar, Oxford PA). Contigs were screened and conflicts resolved manually. Contigs were then BLASTed using BLASTx function of the Wisconsin Package v10.3 and processed for GO relationships using the GO-BLAST package developed by the USDA-ARS Livestock Issues Research Unit and entered into the BryoBase website. From this collection, a unigene set of ESTs has been developed to produce a Tortula rehydration microarray for gene expression studies. The EST collection also contains a small subset of sequenced, mostly novel SSH clones (384 from rehydration and 384 from mRNP collections). These clones have been used to initiate a microarray-based study for gene expression profiling during the desiccation/rehydration response in Tortula. Using both total and polysomal mRNA transcripts for the source of cDNA probes, we have evaluated the relative importance of transcript abundance and recruitment in the response for each represented gene. The data we will present offers a unique picture of the transcriptome (and 'translatome') level response of T. ruralis to severe stress.