Abstract: In order to deeply understand the effect of CsamiR399b on cucumber fruit expansion, the bioinformatics analysis of CsamiR399b and its target gene CsUBC24 were carried out, and the expression characteristics of CsamiR399b was analyzed using qRT-PCR. The results showed that the CsamiR399b precursor sequence contained the complete stem-loop. CsamiR399b showed higher expression level in expanding fruit than in ovary(0 d)and unexpanding ovary, which proved that CsamiR399b involved in fruit expansion of cucumber. Bioinformatics analysis showed that the secondary structure of CsUBC24 protein was mainly composed of random curl and α-helix. CsUBC24 protein was a soluble protein without signal peptide and transmembrane structure, which might be located in the nucleus. Phylogenetic tree indicated that cucumber CsUBC24 shared highly similarity with UBC24 from melon, pumpkin and balsam pear. The sequence and functional domain of UBC24 protein among differential species were highly conserved based on the analysis of sequence alignment and conserved domain, which indicated the conserved function among differential species. The results suggested that CsamiR399b involved in fruit expansion of cucumber by regulating the expression of CsUBC24, which would provide a basis for further studying the function of CsamiR399b and its target gene CsUBC24 in cucumber fruit expansion.

Key words: Cucumber, Fruit expansion, miR399b, UBC24, Bioinformatics analysis

CLC Number: 

• S642.2