The Construction And Genectic Transformation Of The Gene BjuA.YSC Expression Vector

The yellow seed is showed to be associated with the expression of the genes for flavonoid synthesis in Brassicajuncea. It is suggested that the transcription factors MYB, bHLH and WD40are the key factors responsible for difference in seed coat color. In this study, the gene BjuA.YSC our lab has cloned from Brassica juncea was used to study its function by complementation, which will provide the foundations for molecular mechanism of the yellow-seeded trait.Expression vector of the gene BjuA. YSC was constructed and introduced into the Agrobacterium tumefaciens strain EHA105by the freeze-thaw method in this study. The hypocotyls from aseptic seedlings of B. juncea cv. Sichuan Yellow were used as explants for transformation. The main results are as follows:1. The expression vector pBl-BjuA. YSC was constructed and transferred to competent E. coli cells for amplification.2. The transformation system based on hypocotyl explants and Agrobacterium tumefaciens strain EHA105was established for the species Brassicajuncea.3. The24kanamycin-resistant plantlets were regenerated from6400explants and three transgenic plants confirmed by PCR analysis. The transformation rate was estimated to be0.046%. The transgenic plants developed normally, flowered and set fruits and seeds. However, their seeds remained yellow like the untransformed parent.