Improving sulforaphane content in transgenic broccoli plants by overexpressing MAM1 , FMO GS–OX2 , and Myrosinase

Sulforaphane (SF) is a potential secondary metabolite with anticancer activity and its metabolic pathway has been revealed in the model plant Arabidopsis thaliana. Generally, the SF extraction cycle from broccoli is long and the yield is low, which means that it no longer meets cancer treatment requirements. Therefore, the SF content needs to be urgently improved. In this study, MAM1, FMOGS–OX2, and Myrosinase, which are required for SF biosynthesis, were introduced into broccoli by Agrobacterium tumefaciens-mediated transformation. To obtain plants with a higher SF content, broccoli was transformed using Myrosinase-FMOGS–OX2-MAM1 (M-F-A) triple genes in tandem and by adding each of the genes on their own. The results showed that the SF contents in the MAM1, FMOGS–OX2, or Myrosinase transgenic plants improved by 1.7–3.4, 1.6–2.7, and 3.7-fold compared to the wild type (WT), respectively, However, the SF contents in transgenic plants with all three genes improved by 1.86–5.5fold. Furthermore, we examined the anticancer effect of the SF extracts from transgenic plants via cell viability detection of HCT116 colon cancer cells. The results showed that SF extracts from transgenic plants had more obvious anticancer activity than SF extracts from WT, and the SF extracts from the multiple genes plants had stronger anticancer activity than the single gene plants. In summary, the multiple genes transformation increased the SF content in broccoli more than single gene introductions. The aim of this research was to improve sulforaphane content by introducing FMOGS–OX2, MAM1, and Myrosinase genes, and Myrosinase-FMOGS–OX2-MAM1 (M-F-A) serial triple genes into broccoli.