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The cis-regulatory elements of promoters regulate temporal and spatial expression of genes.DNA methylation,histone methylation and histone acetylation are the main types of epigenetic modifications,which play important roles in plant growth and development.DNA methylation could scilence transposons,affect gene imprinting and gene expression.In this study,we found that granule bound starch synthase 1(GBSS1) gene is expressed specifically in wheat endosperm rather than in the embryo.We also analyzed the cis-elements within this promoter region and found some seed-specific elements.In order to confirm the tissue specificity,we cloned 4k bp sequences upstream of GBSSl gene to link to vector with GUS and this construct was transferred to tobacco by Agrobacterium mediated transformation.The results showed that wheat GBSS1 promoter mediated the seed-specific expression of GUS gene,but not mediated expression in embryo.In addition,we found that GBSS1 promoter is methylated in wheat embryo and de-methylated in wheat endosperm.Our study might provide the molecular basis for specific expression of GBSS1 gene.
The cis-regulatory elements of promoters regulate temporal and spatial expression of genes. DNA methylation, histone methylation and histone acetylation are the major types of epigenetic modifications, which play important roles in plant growth and development. DNA methylation could scilence transposons, affect gene imprinting and gene expression.In this study, we found that granule bound starch synthase 1 (GBSS1) gene is expressed specifically in wheat endosperm rather than in the embryo. We also analyze the cis-elements within this promoter region and found some seed-specific elements . In order to confirm the tissue specificity, we cloned 4k bp sequences upstream of GBSS1 gene to link to vector with GUS and this construct was transferred to tobacco by Agrobacterium mediated transformation. The results showed that wheat GBSS1 promoter mediated the seed-specific expression of GUS gene, but not mediated expression in embryo. Addition, we found that GBSS1 promoter is methylated in wheat embryo and de-methylated in wheat endosperm. Our study might provide the molecular basis for specific expression of GBSS1 gene.