Cloning and Expression Analysis of a Novel Abiotic Stress-induced Wheat Genes

【Objective】Water stress and cold stress are important factors restricting plant growth. However, there is little knowledge on the function of stress-responsive genes in plant. Therefore, it is necessary to clone some important genes to study the mechanism of plant adaptation to abiotic stress for the improvement of plant resistance. Our objective is the cloning of water stress-related genes, and providing candidate genes for stress-resisted plant breeding. 【Method】A putative water stress-induced gene, W89, was cloned from the cDNA library of drought-treated wheat seedlings by phage hybridization in situ. Its entire length was obtained using 5′-rapid amplification of cDNA ends (RACE) and reverse transcription–polymerase chain reaction (RT-PCR). 【Result】The full-length cDNA of W89 consists of 2 392 bp and contains a 1 896 bp open reading frame (ORF) encoding a 631 amino acid protein. Southern blot analysis indicated that W89 was a single-copy gene. RT-PCR analysis revealed that the expression of W89 was unregulated by drought, cold and abscisic acid (ABA). Amino acid sequence analysis discovered that W89 had a conserved region of DUF248 (pfam03141), which contained a methyltransferase domain with a sterile alpha motif (SAM)-binding motif. Phylogenetic analysis showed that W89 was 66% identical to Oryza sativa dehydration-responsive protein (BAD67956). It was supposed that W89 was a novel dehydration-responsive protein encoding gene. 【Conclusion】Based on the functions of methyltransferase and SAM-binding motif, the SAM-binding motif of W89 was supposed to be connected with other proteins or transcription factors to transduce stress signals and finally regulate the expression of stress-responsive genes on the early stage ofdrought stress.