Analysis of gene expression data generated by high-throughput microarray transcript profiling experiments coupled with cis-regulatory elements enrichment study and cluster analysis can be used to define modular gene programs and regulatory networks. Unfortunately, the high molecular weight glutenin subunits of wheat (Triticum aestivum) are more similar than microarray data alone would allow to distinguish between the three homoeologous gene pairs. However, combining cDNA expression libraries with microarray data a co-expressional network was built that highlighted the hidden differences between these highly similar genes. Duplex clusters of cis-regulatory elements were used to focus the co-expressional network of transcription factors to the putative regulatory network of Glu-1 genes. The focused network helped to identify several modules of transcriptional gene programs in the endosperm. Many of these programs demonstrated a conserved temporal pattern across the studied genotypes, however few others showed variance. Based on this network, transient gene expression assays were performed with mutated promoters to inspect the control of tissue specificity. Results indicated that the interactions of the ABRE│CBF cluster with distal promoter regions may have a dual role in regulation by both recruiting the transcription complex as well as suppressing it in non-endosperm tissue. A putative model of regulation is discussed.

Abstract:Abstract The precise elimination of selectable marker genes is highly desirable, when their function is no longer needed, because their presence raised worldwide public concerns against the release of genetically modified plants. This is the first report of simultaneous application of the minimal gene cassette and cold-inducible Cre/lox recombination system in wheat. The bar selection and cre-recombinase genes were eliminated from T0 and T1 transgenic lines with 44% and 51% efficiency. This approach provides a new, reasonably effective technique to produce selection genefree transgenic wheat lines either immediately after tissue culture, or from the subsequent transgenic generation. The advantage of this method is that it does not require any additional cold treatment during the plant regeneration/growing because the transgene elimination is ensured by the vernalisation. Application of this method prevents gene flow by pollen and seed, because the selection and recombinase genes are eliminated before pollen development, therefore reducing the risk of GM plants. Powered by Editorial Manager® and ProduXion Manager® from Aries Systems CorporationGenerating marker-free transgenic wheat using minimal gene cassette and cold inducible Cre/lox system AbstractThe precise elimination of selectable marker genes is highly desirable, when their function is no longer needed, because their presence raised worldwide public concerns against the release of genetically modified plants. This is the first report of simultaneous application of the minimal gene cassette and cold-inducible Cre/lox recombination system in wheat. The bar selection and cre-recombinase genes were eliminated from T 0 and T 1 transgenic lines with 44% and 51% efficiency. This approach provides a new, reasonably effective technique to produce selection gene-free transgenic wheat lines either immediately after tissue culture, or from the subsequent transgenic generation. The advantage of this method is that it does not require any additional cold treatment during the plant regeneration/growing because the transgene elimination is ensured by the vernalisation. Application of this method prevents gene flow by pollen and seed, because the selection and recombinase genes are eliminated before pollen development, therefore reducing the risk of GM plants.

No abstract