SlMYB1 regulates the accumulation of lycopene, fruit shape, and resistance to Botrytis cinerea in tomato.

Fruit lycopene, shape, and resistance are essential traits in vegetables whose final product is fruit, and they are also closely related to and strictly regulated by multiple transcription factors. Lycopene, which cannot be synthesized by the human body and can only be ingested from the outside, was important in maintaining human health. During fruit ripening and post-harvest, tomato plants face a variety of biotic or abiotic stresses, which might inflict great damage to fruit quality due to its flat shape and pointed tip during storage and transportation. Therefore, there is an urgent need for key molecular switches to simultaneously improve fruit lycopene and resistance to biotic stress during ripening. Here, we identified the MYB transcription factor in tomato plants which could bind to the promoters of lycopene synthesis-related genes, , and the pathogen-related gene directly, to regulate the fruit lycopene and resistance to in tomato. In addition to regulating lycopene synthesis, also regulates the content of soluble sugar, soluble protein and flavonoid in tomato. What's more, could regulate the tomato fruit shape, making it smoother or flatter to prevent skin damage caused by vibration on fruits. RNA sequencing (RNA-seq) further showed that fruit-specific expression lines had multiple differentially expressed genes compared with those from wild-type plants, suggesting that might have multiple roles in fruit nutritional quality control and resistance to stresses, which is a rare occurrence in previous studies. In summary, our results revealed that was an essential multi-functional transcription factor that could regulate the lycopene and resistance to , and change the shape of fruit in tomato plants.