Functional Analysis Of TFⅢA-Type Zinc Finger Protein Gene ZFP207 From Rice (Oryza Sativa L.)

Zinc finger protein is one type of transcription factors and plays important roles in the processes of growth and development and stress response. The identification of zinc finger protein will not only be helpful to understand the life cycle of plants, but also be helpful for the genetic improvement of crops. ZFP207 is the first TFⅢA type zinc finger protein with single zinc finger in rice.In this thesis, the function of ZEP207 was identified and the main results are given as follows.ZFP207 encodes a protein of 188 amino acid residues with a molecular mass of 20.72 kDa. The sequence analysis shows that any known nuclear related motifs are not found in the ZFP207 protein.We found that the green fluorescence of GFP-ZFP207 fusion protein was observed in the nuclear of onion cell under UV, so the ZFP207 is a nuclear-localized protein and we speculate that ZFP207 moved into the nuclear by interacting with other proteins with NLSs or by unknown NLSs in itself. ZFP207 couldn’t activate the expression of reporter genes in yeast and the fragment of ZFP207 without EAR-motif still couldn’t gain the ability of transcription activity, so we speculate that ZFP207 may function as a repressor in rice. Tissue expression analysis revealed ZFP207 was expressed with high level in stem and leaf, but with low level in root and spike. ZFP207 was induced by salt, cold, drought and ABA treatment in rice seedlings with different model between the the aerial parts and root. Agrobacterial mediating method was used to generate ZFP207 over-expression and knock-down rice plants. The over-expression of ZFP207 in rice resulted in low plant height, reduced spikes, low seed-setting and germination rate. The SEM analysis shows that the cell size in the longitudinal section is shorter in the transgenic plants and this partially causes the phenotype of dwarf.