Efficient generation of pink-fruited tomatoes using CRISPR/Cas9 system

Tomato （Solanum lycopersicum） is the leading vegetable crop worldwide and an essential component of a healthy diet （Lin et al., 2014; Du et al., 2017）. Fruit color is regarded as one of the most important commercial traits in tomato （The Tomato Genome Consortium, 2012）. Consumers in different regions have different color preferences. For example, European and American consumers prefer red tomatoes, while pink tomatoes are more pop- ular in Asia countries, particularly in China and Japan （Ballester et al., 2010; Lin et al., 2014）. However, most of tomato breeding ma- terials are red-fruited, thus the generation of pink-fruited materials is very important for Asian tomato production. Metabolomics and genetics studies demonstrate that the pink trait results from the absence of yellow-colored flavonoid naringenin chalcone （NarCh） in the peels,