Gene Expression Atlas of Grain Development in Wheat

Wheat is globally one of the most important crops. In recent years, there has been significant interest to improve this crop to meet the current and future global demands. Recent advances in genomics based approaches are contributing to development of new tools for applications in several crops. We are using genomics based approaches to advance the understanding of grain development in wheat. Towards this goal, we focused our studies on developmental and gene expression programs of grain from fertilization to maturity in hexaploid, tetraploid and diploid wheat species. These studies include dissection and isolation of tissues from key phases of grain development and detailed analyses of these using Nomarski and electron microscopy, followed by RNA-seq based approaches to profile transcriptomes associated with these tissues. Analyses of the results revealed gene expression programs specific to embryo, endosperm and pericarp compartments as well as dynamic programs that are regulated coordinately between these tissues and different genomes. Comparative expression analysis of A, B and D genomes suggest differential regulation of some of the alleles representing these three genomes. Key findings from these studies and their implications to grain development in wheat will be presented.