Overexpression of BCAT4, CYP79F1 and ESM1 Promote Sulforaphane Yield in Broccoli Cells
ZHANG Youqi, CAO Haiyan, LIU Danmei, ZHANG Jinhua, FAN Sanhong, JIN Zhuping*, PEI Yanxi*
SFN (sulforaphane) is one of the plant natural product with best anti-cancer effect at present. Broccoli, a Brassicaceae plant, is an important material for the production of SFN. However, the yield of SFN in broccoli is very low, and far from meeting market demand. Previous research strategies to improve SFN synthesis via single genetic modification in plants were not ideal. In this study, three important SFN synthesis related genes, branched-chain amino acid transferase 4 encoding gene BCAT4, cytochrome P450 oxidase encoding gene CYP79F1 and epithiospecifier modifier 1 encoding gene ESM1, were cloned from broccoli. To get more SFN using cell suspension culture, single gene introduction and triple gene serial introduction into broccoli calli were conducted mediated by Agrobacterium tumefaciens and the yield of SFN in the transformed cell line was compared with wild type cells. The results showed that the target genes BCAT4, CYP79F1, ESM1 and BCAT4N-SCYP79F1N-SESM1 (B-C-E) were successfully integrated with the genomic DNA of the host cell. The SFN content of BCAT4 and BC-E gene overexpressed cell lines was 139.7 and 171.4 μg/g, which were 1.79 and 2.19 times of SFN in wild-type cell, respectively. And the difference was extremely significant. The SFN content of B-C-E gene overexpressed cell lines was 1.23 times of BCAT4 gene overexpressed cell lines. And the difference was significant. However, the overexpressed cell lines of CYP79F1 and ESM1 did not detect a higher SFN content than the control. In summary, the overexpression of single gene BCAT4 has a greater effect on SFN content than CYP79F1 and ESM1. The effect of multi-gene tandem co-expression on SFN content is better than that of single gene.
CN
EN