A Kelch Domain-Containing F-Box Coding Gene Negatively Regulates Flavonoid Accumulation in Muskmelon

• Published in: Plant physiology (Bethesda) Vol. 169; no. 3; pp. 1714 - 1726
• Main Authors: Feder, Ari, Burger, Joseph, Gao, Shan, Lewinsohn, Efraim, Katzir, Nurit, Schaffer, Arthur A., Meir, Ayala, Davidovich-Rikanati, Rachel, Portnoy, Vitaly, Gal-On, Amit, Fei, Zhangjun, Kashi, Yechezkel, Tadmor, Yaakov
• Format: Journal Article
• Language: English
• Published: United States American Society of Plant Biologists 01.11.2015
• Subjects: American culture; Base Sequence; Biochemistry; Biology; Chalcones - metabolism; Cucumis melo - cytology; Cucumis melo - genetics; Cucumis melo - metabolism; F-Box Proteins - genetics; F-Box Proteins - metabolism; Flavonoids; Flavonoids - metabolism; Fluorescence; FOCUS ON METABOLISM; Fruit - cytology; Fruit - genetics; Fruit - metabolism; Fruits; Gene Expression; Gene expression regulation; Gene Expression Regulation, Plant; Genes; Genetic Loci - genetics; Genomes; Metabolic Flux Analysis; Molecular Sequence Data; Phenotype; Phylogeny; Plant Leaves - cytology; Plant Leaves - genetics; Plant Leaves - metabolism; Plant Proteins - genetics; Plant Proteins - metabolism; Plants; Polymorphism, Single Nucleotide - genetics; Propanols - metabolism; Sequence Analysis, DNA
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.15.01008

The flavonoids are phenylpropanoid-derived metabolites that are ubiquitous in plants, playing many roles in growth and development. Recently, we observed that fruit rinds of yellow casaba muskmelons (Cucumis melo‘Inodorous Group') accumulate naringenin chalcone, a yellow flavonoid pigment. With RNA-sequencing analysis of bulked segregants representing the tails of a population segregating for naringenin chalcone accumulation followed by fine mapping and genetic transformation, we identified a Kelch domain-containing F-box protein coding (CmKFB) gene that, when expressed, negatively regulates naringenin chalcone accumulation. Additional metabolite analysis indicated that downstream flavonoids are accumulated together with naringenin chalcone, whereas CmKFB expression diverts the biochemical flux toward coumarins and general phenylpropanoids. These results show thatCmKFBfunctions as a posttranscriptional regulator that diverts flavonoid metabolic flux.