The characteristics and functions of a miniature inverted-repeat transposable element TaMITE81 in the 5′ UTR of TaCHS7BL from Triticum aestivum
Miniature inverted-repeat transposable elements (MITEs) are truncated derivatives of autonomous DNA transposons, and are dispersed abundantly in eukaryotic and prokaryotic genomes. In this article, a MITE, TaMITE81, was isolated from the 5′ untranslated region (UTR) of TaCHS7BL, chalcone synthase (CHS) catalyzing the first committed step of anthocyanin biosynthesis, in the wheat cultivar ‘Opata’ with white grain. TaMITE81 was only 81 nucleotides, including a terminal inverted repeat with 39 nucleotides and was flanked by two nucleotides, “TA”, target site duplications that were typical features of stowaway-like MITEs. Compared with the wheat cultivar ‘Gy115’ with purple grain, which is without the insertion, the expression of TaCHS7BL was lower in several organs of ‘Opata’. The insertion of TaMITE81 into the 5′ UTR of the GUS gene also reduced the transient expression of GUS on the coleoptiles of ‘Opata’, which means the insertion of TaMITE81 was the reason for the low expression of TaCHS7BL in ‘Opata’. But the genotype of TaCHS7BL was not linked to phenotype of grain color in the RILs derived from a cross ‘Gy115’ and ‘Opata’. The TaMITE81 density of the hexaploid variety of T. aestivum was more than 10 times that of diploid relatives, which implies that polyploidization caused the amplification of TaMITE81 homologous sequences. Further research should be conducted on decoding the relationship between TaCHS7BL and other traits relative to anthocyanin biosynthesis in wheat, and discovering the mechanism of TaMITE81 transposon action.
KeywordsMITE Chalcone synthase Characteristics Function Genetic diversity
This study was financially supported by the Pilot Projects of Designer Breeding by Molecular Module, the West Light Foundation of Chinese Academy of Sciences, Basic Research Projects of Qinghai Province (2015-ZJ-701) and the National Natural Science Foundation of China (Grant Numbers: 31071417).
Compliance with ethical standards
Conflict of interest
The authors have declared that no competing interests exist.
This article does not contain any studies with animals performed by any of the authors.
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