Cloning and expression analysis of sulfite oxidase(DlSO) gene in Dimocarpus longan

【Objective】To investigate the effect of sulfite oxidase(DlSO) gene on the degradation of sulfite residue in longan fruits.【Method】Total RNA from longan fruit(Dimocarpus longan Lour.,‘Shixia')was used as template. RT-PCR combined with RACE was performed to get the full-length c DNA of sulfite oxidase gene c DNA from longan which was named DlSO. Real-Time q PCR was used to analyze the expression of DlSO gene. Prokaryotic expression vector was constructed using Clontech in-Fusion technology to expressed DlSO gene in Rosetta(DE3)【.Result】Sequence analysis show that the cDNA of DlSO is 1413 bp in length. Logenetic analyses demonstrate that Dl SO is closest to Pt SO(Populus trichocarpa) containing a 1182 bp open reading frame(ORF),a 37 bp 5'untranslated region and 194 bp 3'untranslated region,putatively encoding 393 amino acids. Real-Time qPCR results showed that DlSO gene expressed in different tissues of longan,which had the highest expression level in leaves,followed by flowers,young fruits,roots and pulp. The lowest expression level was observed in stem and pericarp. Prokaryotic expression vector p ET-32α-DlSO was constructed and and Dl SO expression was successfully induced by ITPG in Rosetta(DE3).【Conclusion】In this study,the DlSO gene was cloned and successfully constructed and expressed in E. coli.,which has laid the foundation for further study on the role of longan sulfite oxidase.