The Regulation Of AP1 Expression By FT, FD And SOC1

There are four pathways that controlling the flowering time in plants, including photoperiod pathway,venalization pathway,autonomous pathway and gibberellin pathway.So far,some reports have shown that the complex and orderly interaction between different signal transduction pathways during plant flowering.In the study,four Arabidopsis transgenic plants including 35S:APl-3xHA;35S:APl-3xHA ft-10;35S:APl-3xHA fd₃;35S::APl-3xHA socland aplfd3/socl mutants are used as experimental materials.With the major technologies of gateway cloning system,fluorescence quantitative PCR(real-timePCR) and immunohistochemical hybridization(Western-Blotting),We have studied the regulation mechanism of API expression by FT,FD and SOC1 gene at posttranscriptional and posttranslational levels.The results help us to better understand the flowering time regulation in Arabidopsis.The main results are as follows:1.pAPl::APl-3xHA construction was transformated into ap1 mutant and can resume apl mutant phenotype to Arabidopsis Columbia wild-type plant.2.35S::APl-3xHA was compared with 35S::APl-3xHA ft-10 plants about the phenotype,AP1 mRNA and AP1 protein.35S::APl-3xHA ft-10 plant lost the phenotypes APlover-expression and was also late flowering,its AP1 mRNA level and AP1 protein level also decreasedl.3.When 35S::APl-3xHA ft-10 seedling was treated with proteasome inhibitors MG132,MG115,its AP1 protein content gradually increased three hours later after treatment.It suggested FT gene inhibits the degradation of AP1 mediated by proteasome.4.In fd3 or soc1 mutant background,35S:APl-3xHA can not induce earlying flowering anymore.And their AP1 mRNA level and AP1 protein level were also decreased. In conclusion,our results suggest flowering time gene FT,FD and SOC1 regulate AP1 expression at posttranscriptional and posttranslational levels, respectively.