Screening Of Interaction Proteins And Downstream Genes In The Mechanism Of SF2 Gene Regulation Of Cucumber Fruit Length

Cucumber(Cucumis sativus L.)is an important crop in the world,and is one of the largest crop produced in China’s protected land.The important value has penetrated into all aspects of national life.Among them,the character of cucumber fruit is an important reference index for evaluating its market classification.Fruit length,as the main character of cucumber fruit,is complicated because of the dual influence of external environmental factors and intrinsic genetic mechanisms,and the related molecular regulation mechanism is not clear yet.In previous studies,we successfully cloned a single-copy,recessive gene,SF2,which controls the length of cucumber fruits.Through previous phenotypic observations and measurements,we found that the cell division in the mutant was significantly inhibited compared to the wild type.However,the mechanism by which SF2 participates in regulation in vivo is not yet clear.Therefore,this thesis began to study the internal regulation mechanism of cucumber fruit through the co-immunoprecipitation(Co-IP)technique of wild-type and mutants.We could determine the interaction proteins through observing the differences in binding proteins respectively.Chromatin immunoprecipitation(ChIP)was then used to further study the downstream genes involved in fruit regulation,and a large number of important genes related to hormone regulation and signaling pathways were found in the ChIP data.These work laid a solid foundation for the mechanism of completely revealing the length of the fruit in the future.In this study,we found that SF2,a homolog of histone deacetylase Rxt3,may be involved in the formation of the SIN3-HDAC complex,which recruits specific DNA-binding proteins,and controls the deacetylation of specific sites of histones deacetylation regulation.In order to ensure the accuracy of the regulation process,complexes often have a specific structure to identify and function.However,point mutations in SF2 are likely to affect the formation of SIN-HDAC complexes.Rxt3 homologues proteins are highly conserved in plant,and point mutations are likely to affect their regulation of downstream factors or plant hormones in a wide range.Five potential SF2 interaction proteins were successfully found in this article.In order to further verify these five potential protein next step,the corresponding overexpression vectors were constructed,and the transient infection and Western Blot technique were successfully examined in tobacco.In addition,the chromatin immunoprecipitation experiments have found a large number of potential downstream regulatory genes of SF2 protein.These findings initially revealed the regulatory mechanism of SF2,a long-short control gene of cucumber 406 in North China,and also provide a solid theoretical support for cucumber breeding.