Monitoring the expression pattern of 1300 Arabidopsis genes under drought and cold stresses by using a full-length cDNA microarray

Pull-length cDNAs are essential for functional analysis of plant genes, Usi ng the biotinylated CAP trapper method, we constructed full-length Arabidop sis cDNA libraries from plants in different conditions, such as drought-tre ated, cold-treated, or unstressed plants, and at various developmental stag es from germination to mature seed. We prepared a cDNA microarray using sim ilar to 1300 full-length Arabidopsis cDNAs to identify drought- and cold-in ducible genes and target genes of DREB1A/CBF3, a transcription factor that controls stress-inducible gene expression, In total, 44 and 19 cDNAs for dr ought- and cold-inducible genes, respectively, were isolated, 30 and 10 of which were novel stress-inducible genes that have not been reported as drou ght- or cold-inducible genes previously, Twelve stress-inducible genes were identified as target stress-inducible genes of DREB1A, and six of them wer e novel, On the basis of RNA gel blot and microarray analyses, the six gene s were identified as novel drought- and cold-inducible genes that are contr olled by DREB1A, Eleven DREB1A target genes whose genomic sequences have be en registered in the GenBank database contained the dehydration-responsive element (DRE) or DRE-related CCGAC core motif in their promoter regions. Th ese results show that our full-length cDNA microarray is a useful material with which to analyze the expression pattern of Arabidopsis genes under dro ught and cold stresses, to identify target genes of stress-related transcri ption factors, and to identify potential cis-acting DNA elements by combini ng the expression data with the genomic sequence data.