Functional Analysis Of AP2/EREBP-like Transcription Factors In Rice (Oryza Sativa L)

Plant grows in an inconsistent environment of its life cycle. Drought, low-temperature and high-salinity are commonly adverse environment conditions that affect the growth of plants and the productivity of crops. All of these environmental stresses are called water stress. DREB transcription factor is a dehydration responsive element (DRE) binding protein. It can specifically binds to the DRE cis-acting element, plays important roles in the expression of many stress-inducible genes under dehydration, low-temperature and high-salt conditions, and increase tolerance to water stress.In part I, we introduced the transcription factor RdreB1 which isolated by yeast one-hybrid system into rice by using Agrobacterium-mediated transformation. Overexpression of RdreB1 enhanced the tolerance against low-temperature stress in rice.In part II, we examined the structure and function of OsAP22 gene which isolated from yeast using one-hybrid system. Analysis of the deduced amino acid sequence of OsAP22 showed that the protein contained a highly conserved AP2/EREBP DNA binding domain and potential nuclear localization sequence in its N-terminal. In addition, an acidic C-terminal region was identified, which might act as an activation domain for transcription associating with AP2/EREBP transcription factors. Bioinformatics prediction and phylogenetic analysis showed that OsAP22 belongs to the DREB subfamily and shares higher homology with DREB2 type than other type of AP2/EREBP transcription factors on evolutionary relationship.The result of RT-PCR analysis for Oryza Sativa IR36 undergone various treatments indicated that mRNA of gene, OsAP22 was induced effectively by drought and NaCl. We have obtained transgenic Arabidopsis thaliana, Columibia plants. In contrast to no-transgenic plants, these transgenic lines showed strong tolerance to the drought and NaCl stress.