Expression Analysis Of Genes Related To The Metabolism Of Amino Acids During Dedifferentiating Mature Wheat Embryos

Amino acids are not only the material in protein synthesis but some are precursors of several important physiological activators. This paper used wheat cultivar Yumai 18 as material, Affymetrix wheat GeneChip as technique, expression of genes in separated embryos treated by 2,4-D in different time(0-2-6-12-24-72 h) were detected. Different expression of gene related to amino acid metabolism were analyzed in order to elucidated their roles in mature wheat embryos dedifferentiation.Results showed that 44 genes related to amino acid metabolism were found to be significiantly changed. During four stages of dedifferention of mature embryos, i.e. stage of signal transduction (SST, 0～2h), stage of signal response (SSR, 2～12 h), stage of cell remodification (SCR, 12～24h), stage of calli formation (SCF, after 27h), the number of up- and down-regulated genes were 20 and 4, 27 and 9, 16 and 4, 20 and 2, respectively. According to the expression tendances of 44 mentioned above, they could be divided to 3 types: up-, down-, and dominantly down-regulated during all of stages, including numbers of genes in 34, 9 and 1. Among these genes, gene of chorismate synthase was down-regulated by 5.6 times in 12h and the genes of glutamine-hydrolyzing, glutamate decarboxylase, asparagine synthetase, branched-chain amino acid aminotransferase were up-regulated more than 4 times in 72h. These indicated that the genes related amino acid started expression at SST and SSR and played role at SCR and SCF.It was indicated that during the dedifferentiation, the biosynthesis of threonine, methionine, lysine, histidine, aspartic acid were enhanced, while the biosynthesis of tryptophan were attenuated; and the catabolism of cysteine, arginine, tyrosine, phenylalanine, leucine, isoleucine, ornithine and alanine were enhanced too; while the biosynthesis and catabolism of serine, aspartic acid, glycine, valine and glutamine were always active. In summary, metabolisms of amino acid were involved in every stages of dedifferentiation and there were close relationship between metabolism of amino acid and dedifferentiation of mature wheat embryos.This paper used high-throughput expression profile of wheat genomic gene chip to analyze the expression changes of the genes that were related to amino acid metabolism during the dedifferentiation of mature wheat embryos at level of gene transcription. And for the first time amino acid metabolisms were related to the dedifferentiation of mature wheat embryos in this study. It also provided a new way to study the molecular mechanism of embryos dedifferentiation.