Phaseolus vulgaris Genome sequencing and assembly

snap bean are a commonly grown vegetable crop with young pods as edible organs, and high fibre content in the pod wall can lead to poor taste after cooking, and in severe cases can be difficult to consume. Therefore, the fibre content in the pod wall of snap bean is an important economic trait that affects their commerciality. In this study, we used the high pod wall fibre variety P16169 and the low pod wall fibre variety P16341 as experimental materials, and measured the crude cellulose, cellulose, hemicellulose and lignin contents of pod wall fibre during the commercial pod period, and found that the formation of pod wall fibre of the snap bean is mainly related to the content of lignin; we also investigated the lignin content, related enzyme activities, lignin synthesis pathways and the lignin synthesis pathway of the pod walls of the snap bean in the two varieties at different developmental periods. We also analysed the lignin content, related enzymes, intermediate metabolites of lignin synthesis pathway and transcriptome in the pod walls of the two bean varieties at different developmental periods, and found that some enzymes affect lignin formation and genes related to lignin synthesis regulate lignin synthesis mainly by participating in the biosynthetic processes of the cell wall, glucose metabolism and phenylalanine, by using the correlation analyses of physiology, transcriptome and metabolites. This study aims to explore the physiological and molecular mechanisms of pod wall fibre formation in snap bean, and to lay the foundation for future breeding of pod wall fibre in snap bean.