The Primarily Study Of Structure And Function Of Arabidillo-1 In Arabidopsis

This study focuses on the Arabidillo-1 which is an Arabidopsis gene. We first get some information about Arabidillo-1 from many databanks of Arabidopsis, and analyzed it using many soft of Bioinformatics. The DNA of Arabidillo-1 has 4044bp and the mRNA contains 2793 bp, and it expresses a protein which has 930 amino acids. ARABIDILLO-1 has an F-box domain in the N-terminal and there are 9 Arm domains in the middle of this protein. We cloned the gene of Arabidillo-1 from the Arabidopsis, and confirmed the sequence of this gene. At the same time, we inserted this gene into the vecter of pUCm-T, and this constructed vector was used as template of Arabidillo-1 in the follow experiments.The ARABIDILLO-1 and YFP fusion protein has been constructed into the binary expression vector pKYL71 and controlled by CaMV35S promotor. The ARABIDILLO-1-YFP has been transferred to Arabidopsis using the floral spray transformation method and tobacco using the leaf disc method, and the YFP fluorescence in the nuclei in many tissues of transgenic plants has been observed with fluorescent microscope. Then we cloned the promoter of Arabidillo-1 and inserted it into pBI121 which is a binary expression vector and contains GUS gene. After transferred this vector into Arabidopsis using the floral spray transformation method, it is found that this gene was all expressed in the root, stem, leaf, and flower, and in the root and flower it was expressed very much. We also purchased the Arabidopsis T-DNA insertional mutant lines of Arabidillo-1. From the study of this mutant, we found that ARABIDILLO-1 can affect the development of lateral root in the help of GA3, While KT, 6-BA, IAA, 2,4-D have no different effct to wild Arabidopsis or mutant. We also found that hign concentration of ion and Verapamil which is Ca²⁺ blocker have no different effct to wild or mutant too.In this study, the Arabidillo-1 was inserted into the vector of pGBKT7 which contains the DNA binding domain, and was hybridized with the 17 members of ASK family which have been inserted into pGADT7 (contain the DNA active domain). The result showed ARABIDILLO-1 can interact with ASK2 and ASK11. Then we divided ARABIDILLO-1 into 9 segments, and those 9 segments were hybridized with ASK2 and ASK11. It was found that ASK2 can interact with all segments of ARABIDILLO-1 which contain the F-box domain, but ASK11 only can interact with the big segment only without the C-terminal of ARABIDILLO-1. This study also found that the homology of ARABIDILLO-1, ARABIDILLO-2 can only interact with the ASK2 of 17 members of ASK family. In our study, we also found ARABIDILLO-1 can not form homodimer and ARABIDILLO-1 and ARABIDILLO-2 can not form heterodimer too.From our study, we guess that the effect of ARABIDILLO-1 to the development of lateral root is through ubiquitin-proteasome pathway, because ARABIDILLO-1 maybe can link some inhibitor of development of lateral root to E3 ubiquitin-protein ligase, and then promotes the degradation of this inhibitor. While, because ARABIDILLO-1 locates in the nucleus, its' effect to the development of lateral root also is because it can affect the expression of some gene. But we have not known why the effect of ARABIDILLO-1 to the development of lateral root needs the help of GA.