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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Plant, Soil and Nutrition Research » Research » Publications at this Location » Publication #312880

Research Project: Genetic and Genomic Basis of Vegetable and Fruit Biology, Quality and Nutrient Content

Location: Plant, Soil and Nutrition Research

Title: A golden SNP in CmOr governs fruit flesh color of melon (cucumis melo)

Author
item TZURI, GALIL - Agricultural Research Organization Of Israel
item ZHOU, XIANGJUN - Cornell University - New York
item CHAYUT, NOAM - Agricultural Research Organization Of Israel
item YUAN, HUI - Cornell University - New York
item PORTNOY, VITALY - Agricultural Research Organization Of Israel
item MEIR, AYALA - Agricultural Research Organization Of Israel
item SAAR, UZI - Agricultural Research Organization Of Israel
item BAUMKOLER, FABIAN - Agricultural Research Organization Of Israel
item MAZOURECK, MICHAEL - Cornell University - New York
item LEWINSOHN, EFRAIM - Agricultural Research Organization Of Israel
item FEI, ZHANGJUN - Cornell University - New York
item SCHAFFER, ARTHUR - Agricultural Research Organization Of Israel
item Li, Li
item BURGER, JOSEPH - Agricultural Research Organization Of Israel
item KATZIR, NURIT - Agricultural Research Organization Of Israel
item TADMOR, YAAKOV - Agricultural Research Organization Of Israel

Submitted to: Plant Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/23/2015
Publication Date: 3/6/2015
Citation: Tzuri, G., Zhou, X., Chayut, N., Yuan, H., Portnoy, V., Meir, A., Saar, U., Baumkoler, F., Mazoureck, M., Lewinsohn, E., Fei, Z., Schaffer, A., Li, L., Burger, J., Katzir, N., Tadmor, Y. 2015. A golden SNP in CmOr governs fruit flesh color of melon (cucumis melo). Plant Journal. 82:267-279.

Interpretive Summary: Carotenoids are indispensable to plants and humans. Despite significant achievements in carotenoid research, genetic factors that control carotenoid accumulation are not well understood. Here we describe the identification of a melon Orange (CmOr) as the single gene that controls fruit flesh color in melon. We demonstrate that a single SNP in the CmOr is responsible for the orange and non-orange phenotypes in melon fruit. CmOr with the Golden SNP not only provides an excellent genetic tool to study the mechanism underlying the Or-induced carotenoid accumulation in plants, but also offers new approaches for agricultural products biofortification with pro-vitamin A for enhanced crop nutritional value.

Technical Abstract: Melon (Cucumis melo) flesh color is genetically determined and can be white, light green or orange with B-carotene being the predominant pigment. We associated carotenoid accumulation in melon fruit flesh with polymorphism within CmOr, a homolog of the cauliflower BoOr gene, and identified CmOr as the previously described gf locus in melon. Fruit flesh color segregated as a monogenic trait in a population derived from a cross between green flesh and orange flesh melon genotypes, with orange being dominant to green. CmOr was found to co-segregate with fruit flesh color. Two CmOr haplotypes (alleles) were identified in a broad germplasm collection, one being associated with orange flesh and the second with either white or green flesh. Functional analysis of CmOr haplotypes in an Arabidopsis callus system confirmed the ability of the CmOr orange haplotype to induce B-carotene accumulation. Among the identified Single Nucleotide Polymorphisms (SNPs) between CmOr alleles in orange versus green/white-flesh fruit, a single SNP causes a change of arginine to histidine in an evolutionarily highly-conserved location in the CmOr protein in orange melon. The analysis of the site–directed, mutagenized CmOr gene in a heterologous system shows that this SNP can trigger B-carotene accumulation in tissues that do not accumulate carotenoids. Identification of the SNP in CmOr that is responsible for the non-orange and orange phenotypes provides new tools for studying the Or mechanism of action and suggests genome editing of the Or gene for nutritional biofortification of crops.