Cloning And Functional Analysis Of C2H2 Zinc Finger Protein ZFP5 Homologous Genes ZFP3, ZFP1 And ZFP7 In Arabidopsis Thaliana

Arabidopsis trichome is a model system for studying plant cell development.In recent years,there have been many researches about the regulation mechanism of Arabidopsis trichome.However,the research on the key regulatory genes in development of trichome still needs further investigation.Trichomes fur on the surface of the plant,can reduce the loss of moisture and heat,and resist drought,high temperature,UV light and other adverse environments.The metabolites of trichome can not only be used as an exterminator to insects,but also be widely used in cosmetics,medicine and other fields.Moreover,the mechanism of trichome development in Arabidopsis thaliana is similar to that of cotton fiber cell and provides a theoretical basis for it.Abiotic stress is an important factor affecting the yield of global food crops.Our research on stress resistance will provide important theoretical basis for solving this problem.Previous studies in our lab have shown that ZFP5 regulates the initiation of trichomes on inflorescence and responds to the gibberellin signal.ZFP5 acts upstream of the GIS,GIS2,ZFP8 and regulates trichome development by direct targeted ZFP8.In this research,three ZFP5 homologous genes,ZINC FINGER PROTEIN 3(ZFP3),ZINC FINGER PROTEIN 1(ZFP1),ZINC FINGER PROTEIN 7(ZFP7),and GLABROUS INFLORESCENCE STEMS 3(GIS3)were cloned and their function in epidermal hair development and abiotic stress were studied.The main results are as follows:1.Overexpression of ZFP3 significantly increased trichomes number on cauline leaves and stems,while zfp3 mutants and RNAi lines significantly reduced trichomes number on the flowers,branches and cauline leaves in Arabidopsis thaliana.The results also demonstrated that the ZFP3 gene was induced by cytokinin,which affects the development of trichomes.Moreover,genetic analysis showed that ZFP3 acted on the upstream of GL3 and TRY.In addition,ZFP3 overexpression lines also increased the resistance of Arabidopsis to salt stress and osmotic stress,while mutants were more sensitive to salt stress and osmotic stress.Furthermore,ZFP3 could affect the content of proline and chlorophyll,and regulate the expression level of stress-related genes in Arabidopsis.2.ZFP1 overexpression lines significantly increased trichomes number on cauline leaves,branches and stems in Arabidopsis thaliana.zfp1 mutants and RNAi lines significantly reduced trichomes number on flowers,cauline leaves,branches and main stems.The ZFP1 gene was also induced by cytokinin.Meanwhile,the results showed that ZFP1 acted on the upstream of GL3 and TRY.3.ZFP7 overexpression lines significantly increased trichomes number on the 3rd cauline leaves and the 3rd branches,whereas the zfp7 mutant and the RNAi lines significantly reduced tichomes number on flowers,the 3rd cauline leaves and the 3rd branches in Arabidopsis thaliana.The response of zfp7 mutant to cytokinin was significantly lower than wild type.Moreover,ZFP7 overexpression lines and loss-of-function mutant could affect the response to salt stress and osmotic stress in Arabidopsis.4.Our results showed that exogenous cytokinin and gibberellin could significantly increase the level of GIS3 protein.Genetic biology analysis dismonstrated that GIS3 regulated trichome initiation by directly targeted GIS and GIS2.