Functional Study Of Wheat Transcription Factors BZIP And NAC Genes Involved In Abiotic Stress Tolerances

The basic region/leucine zipper (bZIP) and NAC that are pivotal regulators involved ingrowth, development of plants and abiotic stress are important transcription factors in plants. InArabidopsis and rice, many bZIP genes have been reported with roles in response to abioticstresses. However, there are few reports on the stress-related bZIP genes in allohexaploid wheat.In this study, we conducted research concerning the function of wheat transcription factor bZIPand NAC involved in abiotic stress tolerances, which wound provide candidate genes for wheatmolecular breeding in the future. The22TabZIP and28TaNAC genes were screened from wheatfull-length cDNA libraries in our laboratory. The expression patterns of the tissue-specific andabiotic stress response of these genes were studied by semi-QRT-PCR. Some stress-related TabZIPand TaNAC genes were obtained. The functions of these stress-related TabZIP and TaNAC geneswere carried out through ectopic overexpression in Arabidopsis. The main results are as follows:1. Tissue specific anlysis indicated9TabZIP and18TaNAC were expressed in young spikes,leaves, stems and roots. The13TabZIP and10TaNAC genes were expressed differently indifferent tissues. The expression levels of10TabZIP and13TaNAC genes were up-regulatedunder low temperature stress. The expression of13TabZIP and15TaNAC genes increased undersalt stress treatment. For polyethylene glycol (PEG)-induced osmotic stress, the transcriptionexpression of10TabZIP genes enhanced. The expression of15TabZIP genes were induced byexogenous abscisic acid (ABA) treatment.2. TabZIP1gene belonged to the A family of bZIP transcription factor, which was mapped tothe wheat chromosomes6A,6B and6D. TabZIP1protein was localized to the nucleus and hadtranscriptional activity in yeast. TabZIP1gene transcripts were strongly induced by salt, PEG, lowtemperature and exogenous ABA treatments. Over-expression of TabZIP1in Arabidopsis led toenhanced tolerances to salt, drought and freezing stresses. The TabZIP1was capable of bindingABRE sequence by yeast one-hybrid assay and the overexpression of TabZIP1in Arabidopsis ledto greater sensitivity to exogenous ABA in seedling growth. The results indicated TabZIP1participated in ABA signaling pathway.3. TabZIP14gene belonged to the C family of bZIP transcription factor. TabZIP14proteinwas localized to the nucleus and had transcriptional activity in yeast. TabZIP14gene transcriptswere strongly induced by salt, PEG, low temperature and ABA treatments. Over-expression ofTabZIP14in Arabidopsis led to enhanced tolerances to salt and freezing stresses.4. TaNAC47gene belonged to SNAC family of NAC transcription factor. TaNAC47proteinwas localized to the nucleus and had transcriptional activity in yeast. TaNAC47gene transcriptswere strongly induced by salt, PEG, low temperature and ABA treatments. Over-expression of TaNAC47in Arabidopsis led to enhanced tolerances to salt, drought and freezing stresses.5. TaNAC62gene belonged to NTLs family of NAC transcription factor, which was mappedto the wheat chromosomes3A,3B and3D. TaNAC62protein was localized to the nucleus andhad transcriptional activity in yeast. TaNAC62gene transcripts were strongly induced by salt,PEG, low temperature and ABA treatments. Over-expression of TaNAC62in Arabidopsis led toenhanced tolerances to salt, drought and freezing stresses.