Zinc finger proteins comprise a large family and function in various developmental processes. CCCH type zinc finger protein is one kind of zinc finger protein, which function is little known. MsZFN gene encoding a CCCH type zinc finger protein was first discovered by its elevated transcript level in a salt-induced alfalfa SSH cDNA library. The previous experiment had showed that MsZFN protein was localized to the nucleus and little is known about the function of MsZFN protein and its homologous proteins in other plants including model plant, Arabidopsis thaliana. In the current study, we found that MsZFN transcript levels increased in alfalfa under continuous dark conditions and that expression was strongest in leaves and weakest in unopened flowers under light/dark conditions. Expression of MsZFN in transgenic Arabidopsis plants resulted in late flowering phenotypes under long day conditions. Yeast two-hybrid and bimolecular fluorescence complementation assays indicated that MsZFN protein can interact with itself. Transcript analyses of floral regulatory genes in transgenic Arabidopsis showed enhanced expression of the flowering repress or FLC and decreased expression of three key flowering time genes, FT, SOC1 and GI. These results suggest that MsZFN primarily controls flowering time by repressing flowering genes expression under long day conditions.

The research was supported by the Ministry of Science and Technology (the National Science and Technology Supporting Project 2011BAD17B01-01-3) and China Agriculture Research System (CARS-35-04).

 

By Wu Zhenkun
ias@caas.cn