CsRAXs negatively regulate leaf size and fruiting ability through auxin glycosylation in cucumber  

作　　者：Jiacai Chen Liu Liu Guangxin Chen Shaoyun Wang Ye Liu Zeqin Zhang Hongfei Li Liming Wang Zhaoyang Zhou Jianyu Zhao Xiaolan Zhang 

机构地区：[1]Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops,Department of Vegetable Sciences,Beijing key Laboratoy of Growtn and Developmental Regul China Agricultural University,Beijing 100193,China

出　　处：《Journal of Integrative Plant Biology》2024年第5期1024-1037,共14页植物学报（英文版）

基　　金：supported by grants from the National Natural Science Foundation of China[32025033,31930097 and 32372699];Pinduoduo-China Agricultural University Research Fund[PC2023B01002].

摘　　要：Leaves are the main photosynthesis organ that directly determines crop yield and biomass.Dissecting the regulatory mechanism of leaf development is crucial for food security and ecosystem turn-over.Here,we identified the novel function of R2R3-MYB transcription factors CsRAXs in regulating cucumber leaf size and fruiting ability.Csrax5 single mutant exhibited enlarged leaf size and stem diameter,and Csrax1/2/5 triple mutant displayed further enlargement phenotype.Overexpression of CsRAX1 or CsRAX5 gave rise to smaller leaf and thinner stem.The fruiting ability of Csrax1/2/5 plants was significantly enhanced,while that of CsRAX5 overexpression lines was greatly weakened.Similarly,cell number and free auxin level were elevated in mutant plants while decreased in overexpression lines.Biochemical data indicated that CsRAX1/5 directly promoted the expression of auxin glucosyltransferase gene CsUGT74E2.Therefore,our data suggested that CsRAXs function as repressors for leaf size development by promoting auxin glycosylation to decrease free auxin level and cell division in cucumber.Our findings provide new gene targets for cucumber breeding with increased leaf size and crop yield.

关 键 词：auxin glycosylation CsRAXs CsUGT74E2 fruiting ability leaf size 

分 类 号：S642.2[农业科学—蔬菜学]