| Flavonoids are plant secondary metabolites that contribute to the development and adaption of plants to environmental stresses, including resistance to abiotic and biotic stress. Flavonoids are beneficial for human health and depress the progression of some chronic diseases. Wheat is the one of main food crops around the world, and is the main source of nutrients of human being and livestock. Characterization of the flavonoids biosynthesis pathway among different pigmented-grain wheat accessions would be beneficial to know the genetic mechanism and breed wheat cultivars with high content of flavonoids compounds. Furthermore, pre-harvest sprouting (PHS) in cereals (wheat and barley) is a worldwide problem resulting in yield loss and quality deterioration. PHS is influenced seriously by environmental factors (temperature and humidity). Genetic analysis of alpha-amylase (Amy) genes among worldwide germplasms is beneficial for further research on genetic mechanism and resistant breeding. In current study, expression profile of genes related to flavonoids biosynthesis pathway was investigated during grain development in pigmented-grain wheat accessions. Furthermore, the genetic anaylsis of TaAmy (TaAmy1 and TaAmy3) in Triticum aestivum L. was analyzed, the experimental materials included cultivars, landraces and general breeding materials. The main resulted was described as follows:1) Based on observation of grain development and pigments deposition, and expression profile of seven structural genes (Ta4CL, TaCHS, TaCHI, TaF3H, TaF3’H, TaDFR, TaANS) and two regulatory genes (TaMYB, TabHLH), it indicated that pigments began to deposit from 22 days after flowing (DAF) during grain developmental stages (late developmental stage) in pigmented-grain wheat accessions. Pigments firstly deposited at far-end of embryo in deep color wheat accessions (including black, purple, blue), but it turned light green into dark green of grains in light color wheat accessions (including brown, red, grey, white). Furthermore, the transcript levels of related genes were presented higher in deep pigmented-grain wheat than that in light ones. TaF3H and TaF3’H genes might be the most important genes controlling flavonoids biosynthesis during grain development in deep pigmented-grain wheat accessions, and affecting the formation of grain coat with pigments. They might be the key genes affecting the pigmentation in deep color wheat grain. Moreover, the amino acid sequences of upstream structural enzymes presented more conservative than downstream enzymes during flavonoids biosynthesis, ANS enzymes presented the largest variation among the structural enzymes.2) Cloning the TaAmyl, TaAmy3 genes from 234 wheat accessions, and analyzing the nucleotide and amino acid sequences, it indicated that TaAmyl gene contained 4 exons and 3 introns, and the similarly was 96%. In coding sequences,14 SNPs resulting in the variation of amino acids were detected. TaAmy3 gene contained 3 exons and 2 introns, and their similarly was 98.87%. Moreover,15 SNPs was detected in coding sequences of TaAmy3 genes, and they resulted in the variation of amino acids. The two genes had more conservation and less variation among wheat accessions. Significant correlation was not presented between the SNPs and climate types, even between SNPs and materials types among the wheat accessions. Due to the importance of TaAmyl and TaAmy3 genes for germination, it speculated that the breeding process of common wheat (cultivars, landrace and general breeding materials) resulted in the conservation of TaAmyl and TaAmy3 genes. |
