Cloning And Function Characterization Analysis Of SUMO E3 Ligase Gene MdSIZ1 In Apple

Posttranslational protein modification plays an important role in the life, SMALL UBIQUITIN-RELATED MODIFIER(SUMO) is one of the important members.There are three kinds of SUMO E3 ligase in plants, HYP2(At MMS21),SIZ1 and SIZ2.SIZ1 is an important one of SUMOylation E3 ligase, participate in a variety of stress response(high temperature, low phosphorus, etc.).In the previously studies,there are many of them about AtSIZ1 in Arabidiopsis thaliana,but there is no more embedded research in woody plants.The woody plants exist ubiquitin,we speculate that woody may exist SUMOylation modification.Compare with Arabidopsis AtSIZ1 protein sequences we found MdSIZ1 in apple.we proved that the function of MdSIZ1 may also be a SUMO E3 ligase in apple. Carries on the preliminary study on its function, the specific research work and the results are as follows:1. The full length of cDNAs of MdSIZ1 were obtained by using PCR, and the full length of cDNA of ORF is 3141 bp, it encodes a polypeptide including 1047 amino acid residues. The weight of protein is 115.13536 kDa.2. Using fluorescence quantitative PCR analysis expression of MdSIZ1 in apple "Gala" different organizations. Found it expression in all organizations, highest expression in fruit.3. By the protokaryon induction of MdSIZ1, found it location was identical with theoretical value, further prove the veracity of clone.4. The function of MdSIZ1 gene in plants are conservative. Ectopic expression MdSIZ1 gene can improve the adaptability of high temperature and low phosphorus in Arabidopsis thaliana.The germination rate of overexpression Arabidopsis seed is higher than wild type after high temperature treatment,the germination rate of siz1 mutant restore phenotypic seeds are as well as wild type. To observation the root,the adaptability of overexpression MdSIZ1 in low phosphorus environment is increase. Ectopic expression MdSIZ1 gene can also regulation flowering and control the plants size in Arabidopsis.These results of research shows that the apple MdSIZ1 gene regulation the abiotic stress tolerance of plants as the SUMO E3 ligase,and regulation flowering.