Mapping And Functional Analysis Of Cotton Leaf Marginal Blades Lobes Depth Gene LBL1

The leaves are the most important photosynthetic organs of plants.The differences in leaf shape among different species of cotton have important effects on their physiological and agronomic traits such as light energy utilization,maturity,stress tolerance,seed cotton yield,and fiber quality.Cloning and controlling the related genes of cotton leaf margin development will help reveal the molecular mechanism of leaf shape development in cotton,and it also has important significance in the improvement of leaf shape traits.In this study,SBPaes/FBPase activities of the photosynthesis-related enzymes and the sucrose content of petioles and bell-handles of different leaf-shaped plants in the land-land hybrid population were determined.Leaf area,plant height,and fruiting branch number of the individual leaf-shaped plants were investigated and analyzed.The important agronomic traits,such as single boll weight and seed cotton weight,were used to explore the effects of leaf shape differences on the physiological parameters and biomass of cotton plants.The sea-mountain hybrid populations and land-land hybrid populations were constructed separately to construct a leaf shape classification standard.Genetic analysis was performed on the leaf shape traits of cotton.At the same time,the leaf marginal dehiscence depth control gene was precisely mapped and named as LBL(Leaf Blades Lobes)and identified a leucine zipper(HD-ZIP I)transcription factor gene,Gorai002g244000,that encodes a Class I homeodomain,the gene LBL1,which controls the depth trait of cotton leaf margin nicks,and cloned LBL1 in seaweed cotton.Genes were transformed with tobacco and their function was verified.This study laid a theoretical foundation for further investigation of the molecular mechanisms of cotton leaf development and improvement of leaf shape traits.