Fructose-1,6-bisphosphatase Regulates Stem Cell Function Of Arabidopsis Thaliana

Plants maintain the ability to generate new organs throughout their life cycle,which is largely dependent on the maintenance of stem cell activity in the meristem.Stem cells are mainly distributed in shoot apical meristem,cambium meristem and root apical meristem,where WUS、WOX4、WOX5 proteins are specifically expressed and play a crucial role in maintaining the activity of stem cells.Therefore,a complex gene network is formed in plants to participate in the expression regulation of WUS,WOX4 and WOX5 proteins,so as to maintain stem cell homeostasis.FINS1 is fructose-1,6-biphosphatase(FBP)which plays an important role in sucrose synthesis,the Calvin cycle,and gluconeogenesis.Previous studies have shown that FINS1 protein can participate in frustose signaling which is independent of its own enzyme activity.FENS1 protein is also related to H2O2 enzyme in Arabidopsis thaliana.This project mainly studies the roles of FINS 1 in fructose signaling pathway ang H2O2 signaling pathway.The results showed that the FINS1 is universally expressed in almost all tissues of Arabidopsis at different developmental stages and was mainly localized in the nucleus.FINS1 regulates WUS/WOX expression by binding WUS/WOX protein as a complex which further binds to WUS/WOX promoter,thus maintaining the activity of stem cells in meristem.In the fructose signaling pathway,low concentration of fructose can promote the expression of FINS 1 protein,and FINS1 positively upregulates the activity of WUS/WOX promoter by being recruited into a complex with WUS/WOX protein.Howevr,FINSl binds to WUS/WOX protein to repress the activity of WUS/WOX promoter under high Fructose concentration,suggesting that differernt functions of FINS1 mainly depend on the concentration of fructose.In the H2O2 signaling pathway,FINS1 mainly protects stem cells against environmental stress by promoting the expression of WUS/WOX protein in meristem.The loss-of-function of FINS1 gene significantly decreased the expression of WUS/WOX with the increase of H2O2 concentration,and it is difficult for stem cells to maintain homeostasis.