| Reams of studies indicated that plant C2H2-type zinc finger proteins play a wide variety of functional roles spanning floral and leaf development,identity determination of root hairs and epidermal cells,gametophyte occurrence,or response to abiotic stress,metabolism and hormonal signal transduction.The representative characteristic is that C2H2 zinc finger protein contains the C2H2 domain which usually consists of about 30 amino acid residues,combining with DNA,RNA or protein.Though the C2H2 zinc finger protein genes have been well understood in model species such as Arabidopsis and rice,little is currently resolved in Rapeseed.Here,two C2H2 zinc finger protein genes BnZFP5 and BnZFP9 and their promoters were cloned in B.napus through gene expression profile of main inflorescence,and functional roles were quick investigated in Arabidopsis thaliana.The main results are batched as following.1.Differentially expressed gene BnZFP in main inflorescence identified with microarray was homologous to AtZFP5.And AtZFP5 has two homologs named BnZFP5 and BnZFP9 in B.napus by analyzing against B.napus database(http://oilcrops.info).BnZFP5 locates on chromosome A05 and BnZFP9 sets on chromosome A09.BnZFP5 and BnZFP9 harbor conserved domains of C2H2 zinc finger gene family,and consist of 205 and 206 amino acids with 94.7%identity.Consequently,AtZFP5 exhibited 77.4%and 78.4%identities to BnZFP5 and BnZFP9 respectively.2.Ectopic overexpression of D35S::BnZFP5 and D35S::BnZFP9 was performed in Arabidopsis,the transgenic lines showed longer main inflorescence and correspondent more siliques vs.the wild type Col-0.Interestingly,the variation on silique quantity was highly consistent with BnZFP abundance in inflorescence.D35S::BnZFP9 transgenic lines exhibited new features such as delayed flowering,mutant floral organs,shedding florals,ectopic trichomes on young pods and even two or three whorled leaves happened at the site for cauline leaves.However,D35S::BnZFP5 transgenic lines had apparent fewer and shorter root hairs,but no changes occurred on the over-ground part.3.The expression level of BnZFP9 was gradually increased in the different developmental stages(Ⅰ、Ⅱ、Ⅲ、Ⅳ)of three rape lines ZS11、73290 and 07028,especially in the IV stage.4.The promotors of BnZFP5 and BnZFP9 were isolated and assembled as pBnZFP5::GUS and pBnZFP9::GUS and transformed via Agrobacterium mediation into Arabidopsis.The GUS activity indicated that BnZFP5 promoter was mainly in the roots,while BnZFP9 was in root,leaves,trichome,sepal,stigma and floral abscission zone after organ shedding.5.Based on transcriptomic analysis,overexpression of BnZFP9 caused co-expression of a portion of genes related to cell expansion and proliferation,flowering,pectinase metabolism,ethylene signaling,abiotic and biotic responses,suggesting that BnZFP9 may be involved in several processes such as floral organ identity and development,senescence and stress response. |
