| Flowering is an important process in the entire life cycle of plants.Scholars at home and abroad have done a lot of research work on flower organs and flowering process.Flower morphology and flowering are regulated by a complex network of transcription factors and chromatin factors.Among them,Polycomb Repress Complex 2(PRC2)components,FLOWERING LOCUS C(FLC),and FLOWERING LOCUS T(FT)are important genes that affect the flowering process of plants from vegetative growth to reproductive growth.Because ULTRAPETALA1(ULT1)belongs to the Trithorax Group(TrxG),where TrxG is an antagonistic gene of the Polycomb Group(PcG)gene,and the ult1 mutant is different from the wild type in the number of flower organs and flowering time,and plays an important role in flower development.Therefore,studying the function of ULT1 in flower formation has important scientific significance for revealing the mechanism of epigenetic factor interaction.So far,some factors that interact with ULT1 have been found in flower development,such as AG(AGAMOUS),WUS(WUSCHEL),EMF1(EMBRYONIC MERISTEM FLOWER 1),ATX1(ARABIDOPSIS TRITHORAX1),etc.The ULT1 interaction factors have been reported today.Some of the working proteins are the target genes of PRC2,some are the core components of PRC1,and some are members of TrxG However,the interaction between the PRC core component proteins and ULT1 in the flowering pathway remains to be studied.In this study,Arabidopsis thaliana was used as the experimental material to analyze the role of ULT1 in the flowering pathway.In order to study whether ULT1 responds to the effect of vernalization on flowering,the plants were vernalized,and the flowering time data were obtained,and the ult1 mutant,the PcG loss-of-function mutant emf2 vrn2,and flowering-related mutations ft-7 and FRI+,and wild type different responses to vernalization are compared.The results indicate that ULT1 may not participate in the vernalization pathway.The yeast two-hybrid experiment proved that ULT1 and PRC2 components SWN and MS14(FVE)all interact;after knocking out domains on ULT1(SAND and B-box like domains)at the same time,they can still interact with SWN and MSI4.It shows that the SAND and B-box like domains of ULT1 do not play a key role in the interaction.The yeast two-hybrid screening system was used to screen the proteins that interact with ULT1 from the Arabidopsis yeast library.It was preliminarily confirmed that the factors in the yeast library did interact with ULT1 through the rotation experiment.The SWN and FUL(AGL8)components of PRC2 were selected from the candidate genes screened in the library to further verify the interaction with ULT1.In this study,SWN and FUL were respectively constructed on a vector containing GFP-N/C-Venus,and passed Bimolecular Fluorescence Complementation(BiFC)found that ULT1 interacted with SWN and FUL in onion epidermis and tobacco nucleus.In order to explore whether the interaction between ULT1 and FUL has an impact on the fruit,the statistics of the number of siliques per plant of ult1-3 and ful-1,as well as the number of seeds per silique of the fifth and sixth stem nodes,were also carried out at the same time.Time statistics show that the number of siliques per plant of ult1-3 and ful-1 is less than that of the wild type,and the flowering time is later than that of the wild type.In order to explore the interaction between the upstream and downstream of ULT1,some related factors were hybridized with ult1-3 to obtain no downstream relationship between SWN and ULT1 in the regulation of flowering time.TrxG factor ULT1 is involved in the regulation of flowering time,and the regulatory function of ULT1 in plant flower formation is complicated.Studying its regulation mechanism will provide a theoretical basis for exploring the role of epigenetic factors in flowering pathways in the future. |
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