[Construction of a bivalent plant expression vector carrying VvSUC11 and VvSUC12 genes and its genetic transformation...

We have recombined genes VvSUC11, VvSUC12 from Vitis vinifera L., and root-specific promoters of sweet potato storage protein gene from Ipomoea batatas L. Lam., named as SP1 and SP2. We have constructed a vector pCAMBIA2301-SP1- VvSUC11-SP2-VvSUC12 using pCAMBIA2301 as an original vector. VvSUC11 and VvSUC12 were under the control of root-specific promoters of sweet potato storage protein gene. We transformed the vector into KWS-9103 breeding line of Beta vulgaris L. with Agrobacterium-mediated transformation. We have established the optimal genetic transformation protocol of sugar beet as following: the explants pre-cultured for 4 days were immersed in Agrobacterium suspension of OD(600)=0.5, supplemented with 0.005% Silwet L-77, and followed by a 4-day culture on medium containing cefotaxime, then the buds were selected on medium containing kanamycin and cefotaxime. The percentage of kanamycin-resistant buds was as high as 42%. Results of PCR and RT-PCR proved that the target genes had integrated into sugar beet genome and expressed. It will lay a foundation for further studying their function in Beta vulgaris.