Overexpression of a New Zinc Finger Protein Transcription Factor Improves Cold Tolerance in Rice.

Cold stress is one of the most important abiotic stresses in rice. CH zinc finger proteins play important roles in response to abiotic stresses in plants. In the present study, we isolated and functionally characterized a new CH zinc finger protein transcription factor in rice. encodes a CH zinc finger protein, which contains a typical zinc finger motif, as well as a potential nuclear localization signal (NLS) and a leucine-rich region (L-box). Expression of was differentially induced by several abiotic stresses and was strongly induced by cold stress. Subcellular localization assay and yeast one-hybrid analysis revealed that OsCTZFP8 was a nuclear protein and has transactivation activity. To characterize the function of in rice, the full-length cDNA of was isolated and transgenic rice with overexpression of driven by the maize ubiquitin promoter was generated using -mediated transformation. Among 46 independent transgenic lines, 6 single-copy homozygous overexpressing lines were selected by Southern blot analysis and Basta resistance segregation assay in both T and T generations. Transgenic rice overexpressing exhibited cold tolerant phenotypes with significantly higher pollen fertilities and seed setting rates than nontransgenic control plants. In addition, yield per plant of -expressing lines was significantly ( < 0.01) higher than that of nontransgenic control plants under cold treatments. These results demonstrate that was a CH zinc finger transcription factor that plays an important role in cold tolerance in rice.