CmBr confers fruit bitterness under CPPU treatment in melon

• DOI: 10.1111/pbi.14399
• Publication Date: 2024-05-31T04:41:01Z
• Authors: Mingyan Wang; Naiyu Jiang; Yuanchao Xu; Xinxiu Chen; Cui Wang; Chuangjiang Wang; Shiqi Wang; Kuipeng Xu; Sen Chai; Qing Yu; Zhonghua Zhang; Huimin Zhang
• Keywords: Melon

Many biotic or abiotic factors such as CPPU (N-(2-chloro-pyridin-4-yl)-N'-phenylurea), a growth regulator of numerous crops, can induce bitterness in cucurbits. In melon, cucurbitacin B is the major compound leading to bitterness. However, molecular mechanism underlying CuB biosynthesis response different conditions remains unclear. Here, we identified set genes involved CPPU-induced melon fruit and proposed CmBr gene regulator. Using CRISPR/Cas9 editing, confirmed CmBr's role regulating under treatment. We further discovered MYB-related transcription factor, CmRSM1, which specifically binds Myb motif within promoter activates its expression. Moreover, developed an introgression line by introducing mutated Cmbr into elite variety eliminated bitterness, demonstrating potential application breeding. This study offers valuable tool for breeding high-quality non-bitter varieties provides new insights regulation secondary metabolites environmental stresses.