The sugary enhancer1 (se1) Allele Is Associated with Significant Decreases in Carotenoids and Tocotrienols in Yellow (Y1) sugary1 (su1) Sweet Corn

Abstract

A distinctive phenotype of homozygous sugary enhancer1 (se1) sweet corn (Zea mays) inbreds and hybrids is a light-yellow color in mature kernels. Carotenoid pigments contribute to yellow endosperm color in maize and are of nutritional importance in the human diet along with the related tocochromanols, the E vitamins. Tocochromanols, including both tocopherols and tocotrienols, are antioxidants important in human nutrition and cardiovascular health. Effects of the presence of sugary enhancer1 allele on carotenoid and tocochromanol levels in homozygous su1, Y1 endosperm were evaluated in the Wisconsin Sweet Corn Diversity Panel. Although population structure was present in the panel, the majority of variation in carotenoid levels was explained by genotype at the se1 locus. se1 was associated with significant decreases in the amount of lutein (34%) and zeaxanthin (36%) and decreases of tocotrienols by 12% to 65%. There were no significant differences in β-carotene and tocopherol levels between the two groups. Given that the biosynthesis pathways for carotenoids and tocochromanols are well defined, these differences in carotenoids and tocotrienols between su1Se1 and su1se1 inbreds point to a broader role of se1 alleles in metabolic pathways beyond endosperm starch production.