THE ANTHOCYANIN BIOSYNTHETIC REGULATOR MDMYB1 POSITIVELY REGULATES ASCORBIC ACID BIOSYNTHESIS IN APPLE

Ascorbic acid(AsA,vitamin C)is involved in the regulation of many aspects of plant growth and development.It is an essential micronutrient for humans and can prevent scurvy,maintain the health of gums and blood vessels,reduce the level of plasma cholesterol and enhance the immune systen.Apple cultivars Orin and Guanghui were crossed to obtain a group of hybrid offspring with and without red flesh in the course of assessing apple germplasm resources.Unexpectedly,the red-flesh apples had higher AsA contents than other apples.Further studies showed that the anthocyanin biosynthetic regulator MdMYBl directly activates the expression of dehydroascorbate reductase gene MdDHAR,thus promoting the activity of the DHAR enzyme and the accumulation of AsA.This finding reveals the mechanism leading to high AsA levels in red-flesh apples and suggests a new idea to cultivate red-flesh apples with high AsA contents and produce AsA efficiently and without pollution.