A 'golden' SNP in CmOr governs the fruit flesh color of melon (Cucumis melo). (April 2015)

• Record Type: Journal Article
• Authors: Tzuri, Galil; Zhou, Xiangjun; Chayut, Noam; Yuan, Hui; Portnoy, Vitaly; Meir, Ayala; Sa'ar, Uzi; Baumkoler, Fabian; Mazourek, Michael; Lewinsohn, Efraim; Fei, Zhangjun; Schaffer, Arthur A.; Li, Li; Burger, Joseph; Katzir, Nurit; Tadmor, Yaakov
• Is Part Of: Plant journal. Volume 82:Number 2(2015:Apr.)
• Page Start: 267
• Page End: 279
• Publication Date: 2015-04
• Subjects: Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.12814
• Languages: English
• ISSNs: 0960-7412

Abstract

<abstract abstract-type="main" id="tpj12814-abs-0001"> <title>Summary</title> <p>The flesh color of <italic>Cucumis melo</italic> (melon) is genetically determined, and can be white, light green or orange, with β–carotene being the predominant pigment. We associated carotenoid accumulation in melon fruit flesh with polymorphism within <italic>CmOr</italic>, a homolog of the cauliflower <italic>BoOr</italic> gene, and identified <italic>CmOr</italic> as the previously described <italic>gf</italic> locus in melon. <italic>CmOr</italic> was found to co‐segregate with fruit flesh color, and presented two haplotypes (alleles) in a broad germplasm collection, one being associated with orange flesh and the second being associated with either white or green flesh. Allelic variation of <italic>CmOr</italic> does not affect its transcription or protein level. The variation also does not affect its plastid subcellular localization. Among the identified single nucleotide polymorphisms (SNPs) between <italic>CmOr</italic> alleles in orange versus green/white‐flesh fruit, a single SNP causes a change of an evolutionarily highly conserved arginine to histidine in the CmOr protein. Functional analysis of <italic>CmOr</italic> haplotypes in an Arabidopsis callus system confirmed the ability of the <italic>CmOr</italic> orange haplotype to induce β–carotene accumulation. Site‐directed mutagenesis of the CmOr green/white haplotype to change the CmOR arginine to histidine triggered β–carotene accumulation. The identification of the 'golden' SNP in <italic>CmOr, </italic> which is responsible for the non‐orange and orange melon fruit phenotypes, provides new tools for studying the <italic>Or</italic> mechanism of action, and suggests genome editing of the <italic>Or</italic> gene for nutritional biofortification of crops.</p> </abstract>