1. The New 5'-UTR LcyE Allele Correlates with Increased Expression of the Lycopene-ε-Cyclase Gene Determining the Flow of the β-ε Branch of the Carotenoid Biosynthesis Pathway in Maize.
- Author
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Arkhestova, D. H., Efremov, G. I., Appaev, S. P., Kochieva, E. Z., and Shchennikova, A. V.
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LYCOPENE , *CAROTENOIDS , *GENE flow , *GENE expression , *SINGLE nucleotide polymorphisms , *CORN , *BIOSYNTHESIS , *ALLELES - Abstract
The color of the maize (Zea mays L.) grain is determined by the content and composition of carotenoids, including provitamin A, which is a product of the β-β (β-carotene, β-cryptoxanthin) and β-ɛ (α-carotene) branches of carotenogenesis. The ratio of the fluxes of the branches depends on the activity of the lycopene-ɛ-cyclase LcyE, which determines the β-ɛ branch. In this work, we analyzed allelic variants of the LcyE gene, which are potentially effective for increasing the biosynthesis of β-carotene, in 20 maize inbred lines of domestic selection, which differ in grain color. The 5'-UTR regions of the LcyE gene were amplified and sequenced. Fragment analysis showed the presence of allele 2 in four lines and the new allele 5 in 16 lines. The polymorphism of the new allele 5 was characterized—four single nucleotide polymorphisms and two deletions. The comparison of cis-regulatory elements in the analyzed 5'-UTR region in alleles 2 and 5 revealed a difference in binding sites with transcription factors. Expression of the LcyE gene was determined in the leaves of two lines with allele 2 and three lines with allele 5. A direct relationship was shown between the presence of allele 5 and a decrease in gene expression: the level of gene transcription in the case of allele 2 was 10–15 times higher than in the case of the allele 5. It has been suggested that the presence of allele 5 of the LcyE gene in the maize genome correlates with a decrease or suppression of the LcyE expression and, with stable activity of other carotenogenesis enzymes, with grain color. The use of allele 5 donors in combination with a known dark yellow or orange color of the grain can be used in the breeding of maize with increased synthesis of provitamin A in the grain. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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