Analysis Of Gene Expression Differences Of Differentiation And Dedifferentiation In Mature Wheat Embryos

The differentiation and dedifferentiation of cell are two different biological processes of tissue culture. To elucidate the mechanism of mature wheat embryo dedifferentiation and differentiation, expression profile of genes in dedifferentiation was studied by Affymetrix microarray technique in mature embryos of wheat cultivar Yumai 18 cultured on MS medium supplemented with or without 2,4-dichlorophenolxyacetic acid (2,4-D, 2 mg L?1). The main results were as follows:1) 2,4-D plays a decisive role in the dedifferentiation of wheat mature embryo. The results of mature wheat embryo culture process showed that the mature wheat embryo is a natural germination without 2,4-D in medium, so growed roots firstly, and then sprouted. Callus was formed in the medium with 2,4-D, and more and more callus were found. The isolated mature wheat embryos were observed constantly larger and larger. It was showed that 2,4-D played a decisive role to change the fate of mature wheat embryo in vitro culture.2)The genes which related differentiation and dedifferentiation of wheat mature embryo were classificated. Among of 341 meaningful genes, 13 genes were related to cell wall, 23 genes were related to cell membrane and physical transportation, 33 genes were related to signal transduction, 4 genes were related to ion channels and transport, 7 genes were related to protein synthesis, 37 genes were related to protein processing and storage, 9 genes were related to amino acid metabolism, 8 genes were related to lipid metabolism, 20 genes were related to glucose metabolism, 9 genes were related to energy metabolism, 7 genes were related to cytoskeleton, 7 genes were related to transcription factor genes, 9 genes were related to molecular chaperone genes. 12 genes were related to translation modification of transcription, 13 genes were related to chromosome, 2 genes were related to cell division, 7 genes were related hormone, 2 genes were related to germination, 3 genes were related to detoxification, 7 genes were related to function trace element, 16 genes were related to pathogenesis, 19 genes were related to the corresponding stress, 7 genes were related to hypothetical protein, 14 genes were related to unknown protein, 53 gene were other.3)The analysis of functional gene expression. Expansin was up-regulated during differentiation and dedifferentiation of mature embryo, which can change cell structure. X13913.1 which encoded signal recognition particle was up-regulated in dedifferentiation and down-regulated in differentiation; it can have an effect in the protein fold process. Gene BJ305759 codes glutaredoxin-like protein, in dedifferentiation which is 3.5 times as in the differentiation., it played an important role in the process of cell internal oxidation returning to original state the state of equilibrium regulation and the resistance oxidation stress damage. the genes of ribosomal protein expressed similarly in dedifferentiation and differentiation.Encoding three family-type MYB transcription factor genes, three encoding bZIP transcription factor family gene and a gene encoding bZIP transcription factor gene families, these genes in dedifferentiation expressed strenger than the expression of differentiation, Confirmed initially that these genes received the 2,4-D stimulation and responsed in the process of dedifferentiation and differentiation. More cell skeleton protein gene expressed upward in dedifferentiation and differentiation, the mature embryo already received the 2,4-D stimulation, and developed to two different directions in 24 hour. BJ211972, putative RNA helicase was downwarded in dedifferentiation and increased in differentiation, we extrapolated that it can promote the cell division and form the new organization organ. These different expressions might play an important role in triggering in dedifferentiation of mature embryos in wheat and their proceeding.