Functional Analysis Of A BZIP Transcription Factor TaGBF2of Wheat

Common wheat (Triticum asetivum) is one of the most widely distributed and planted crops in the world. It is very important in molecular breeding to explor genes that controlled agricultural traits from specific germplasm. In our previous work, a new somatic hybrid introgression line Shanrong No.3(SR3) was generated using common wheat Jinan177(JN177) and Thinopyum ponticum, a salt and drought tolerant grass. Compared with the parent JN177, many genes associated with resistance have changed expression patterns in SR3under abiotic stress, including many types of transcription factors.bZIP is the most widely distributed and conservative class of protein in eukaryotic transcription factors. According to the basic and additional domain, bZIP protein family can be divided into10subfamilies. G family members have been mainly linked to ultraviolet and blue light signal transduction and to the regulation of light-responsive promoter.We clone the gene of TaGBF2from the SR3cDNA library. The gene contains the conserved bZIP domain, and belongs to the G subfamily of bZIP proteins. TaGBF2has the highest homology with dicotyledonous plant corn ZmGBFl and rice OSBZ8. Among alignments with the Arabidopsis G subfamily bZIPs, the TaGBF2has the highest homology with AtGBF2gene, thus the gene is named TaGBF2. We clone and get TaGBF2genome sequence, which contains ten introns. In dark, TaGBF2is located in the nucleus. Under NaCl, and PEG treatment, the expression of TaGBF2is up-regulated; Under H2O2treatment, the gene expression level is lowered in a short period of time; Under phytohormone ABA treatment, the expression of TaGBF2is also up-regulated. TaGBF2is mainly expressed in the root, followed by the embryos, low in leaves. The expression pattern study of TaGBF2gene under different light qualities shows that TaGBF2has high expression level in the dark than white, blue light can induce the expression of the gene, and the red light can decrease the expression of the gene. Compared with wild type Arabidopsis, TaGBF2over-expresser Arabidopsis have shorter hypocotyls in white or blue light, however TaGBF2over-expresser Arabidopsis have identical phenotype with wide type Arabidopsis in red light or darkness. Compared with wild-type Arabidopsis, the TaGBF2over-expresser Arabidopsis have higher sensitivity to mannitol, NaCl, H2O2, ABA, and lower gemination rate on1/2MS containing Mannitol. This paper preliminarily proves that TaGBF2is a member of the blue light signaling pathway and the gene expression of TaGBFI can response to various abiotic stress factors. The ectopic over-expression of TaGBF2gene increase the sensitivity of plants to abiotic stress.