"Genetic silencing" allows genetically modified apples in the United States to be cut open for three weeks.

Originally published as "Genetic silence" lets U.S. genetically modified apples cut for three weeks unchanged
Arctic apples were sold in a handful of midwestern states in February 2017 and are scheduled to go on sale in California this month, possibly in sliced bags, and are expected to go on sale in other U.S. regions by the end of 2017. On the 15th, Jinqi Ren, a postdoctoral student in the Department of Pharmacology at the University of North Carolina School of Medicine, told Science and Technology Daily.
Arctic apples change color after three weeks of cutting, why? "The leaf bubbles in apple cells contain some unusual organic matter - polyphenols, while the foliars and mitochondrials contain polyphenol oxidases. Normally, the two are in different places and do not meet. Jiang Wei, a senior engineer at the Institute of Genetics and Developmental Research of the Chinese Academy of Sciences, told Science and Technology Daily that when apples are cut open or cells are damaged, polyphenol oxidases and polyphenols meet, and the former uses oxygen in the air to oxidize polyphenols to produce quinines, and then after a series of reactions, the color becomes heavier and heavier, from light brown to brown.
researchers used a technique called "gene silencing" to reduce the amount of mRNA, the synthetic template that controls polyphenol oxidases, while the expression activity of polyphenol oxidase genes remained the same.
"gene silencing" technology is a molecular biology technology explored by scientists, and has been widely used in basic research to adjust gene expression, for the first time in the field of food consumed by society.
"The 'production' of polyphenol oxidases in apple cells is divided into three key stages, the first is the transcription phase of gene expression, which produces mRNA templates for polyphenol oxidases; Jiang said.
He explains that "gene silencing" does not directly inhibit the amount of mRNA produced by genes, but degrades 90 percent of them in the second phase, leaving 10 percent of the mRNA template for the synthesis of protein enzyme molecules in the third stage, and that the browning process of apple indations is much slower than non-GMO as protein products are significantly reduced. (Ma Aeping)