Cloning And Function Analysis Of PpDREB-like Gene In Physcomitrella Patens

The plants are greatly affected by environmental stresses such as freezing, drought, and salt. The plants can activate some proteins that are related to the tolerance or regulate the activity of enzymes by the signal pathway. The transcription factors play crucial roles in gene expression. There are some transcription factors related to abiotic stresses in plants.and they can be regulated by the signal transduction pathway. DREB proteins belong to AP2/EREBP transcription factors and are specific in plants. They are very important in mediating abiotic stresses such as cold, drought and high salt. DREB ptoteins can induce the expression of some target genes so that the plants can enhance the tolerance to drought and other stesses.Improving the tolerance of plants by using transcription factors has significance in theoretical and practical aspects.Physcomitrella patens has strong resistance to cold, drought and salty stresses and there are so many genes that can improve the tolerence of plants. Here, a gene is cloned by RT-PCR and RACE in physcomitrella patens It has a conserved AP2 domain and we named it PpDREB-like gene. The PpDREB-like gene belongs to AP2/EREBP transcription factors and the blast results show that it has more homology with DREB subfamily. In addition, it has conserved V14 and E19 of DREB subfamily. So the PpDREB-like gene is thought to be one of DREB subfamily. The results of RT-PCR under different stress conditions show that the expression of PpDREB-like can be induced by drought but not by redehydration and cold, high salt in 5 hours..Forthermore, the PpDREB-like gene was transformed into yeast and tabacoo suspension cell and its function is analyzed simply. Transgenic yeast and BY-2 cell exhibit certain resistance to osmotic stress compared with control. It indicates that the PpDREB-like protein can activte some target genes as a regulatory protein so that the cells can improve the torlerance to drought and other stresses. For further functional analysis on this gene, a anti-sense vector was constructed and transformed into BY-2 cell. The callus is being researched.