Identification And Expression Analysis Of BHLH Transcirption Factor Genes In Wheat

bHLH proteins are the second largest class of plant transcription factors (TFs). They play importantroles in regulate plant development and abiotic stress response. But little is known about bHLH inwheat compared with model plants at present. In this study, we plan to study bHLH in wheat using thefull length cDNA resources constructed by our lab. We hope that wheat bHLH gene information andgene response to abiotic stress will be provided and benefit to wheat stress tolerance molecular breeding.So far,23wheat bHLH genes were identified and tissue specific expression patterns and expressionprofiles response to abiotic stress were obtained.1. After analysising the wheat full length cDNA sequences,23wheat bHLH unigenes with fulllength gene sequences were identified. Phylogenetic anlys is indicated that13wheat bHLH transcriptionfactors had homology with Arabidopsis thaliana, and five other genes were amplified in wheat，none ofthe wheat specific bHLH TFs were identified in this study.2. Tissue specific anlysis showed that21genes expressed in all the tissues of root, stem, leaf, pistiland anther,2genes only expressed in some tissues. Under stresses of salt, PEG, low-temperature andtreatment of exogenous ABA,16genes showed different expression patterns, among them,4genes wereup-regulated under salt stress,4genes were up-regulated under PEG stress,6genes were up-regulatedunder low-temperature stress and10genes were up-regulated under exogenous ABA treatment,respectively.3. Salt stress related gene TabHLH13is1072bp in full length with a720bp ORF, encoding abHLH transcriptional factor with240amino acids. After comparing the genomic sequence with itscDNA sequence of TabHLH13, we found that it contained five exons and four introns. Homologousanalys is found that TabHLH13had a similarity with bHLH proteins from barley and Brachypodium ashigh as96.2%and90.5%, respectively. Using electronic mapping strategy, TabHLH13was mappedonto wheat chromosome7DL. The results of subcellular localization indicated that the TabHLH13protein was a nuclear-localized protein.