Evaluation of Cell Wall Biosynthetic Gene Orthologues in Wheat (Triticum aestivum L.) and Barley (Hordeum vulgare L.)

We are only beginning to unravel the significance of cell wall in human health, biofuels, biotic interactions and the ecosystem. For instance, whole grain cereal dietary fibers are made up of indigestible cell wall components; a complex of carbohydrates that include oligosaccharides, resistant starch and non-starch polysaccharides that are not digested by the enzymes of the small intestine in humans. Cell walls serve as the first layer of defense to pests and pathogens. Modifications and changes in cell wall composition may influence how plants respond to external forces, compounded by climate change. Together, these necessitate a need for understanding the nature of the genes involve in the cell wall biosynthetic pathway within and across species. We are investigating whether cell wall biosynthetic genes in barley are orthologues of those in wheat. Orthologous genes are homologs that are present in the genomes of different species whose common ancestor predates the split between the species. We designed primers from barley sequence to PCR-amplify full length cell wall biosynthetic genes. These primers were used to amplify genes from barley and wheat. The PCR products for both wheat and barley are highly monomorphic. We are sequencing the PCR products to evaluate for Single Nucleotides Polymorphisms (SNPs) and sequence alignment to determine the homology score (degree and percentage of similarity) between the species. We hope that these efforts at understanding the nature of these genes will offer greater flexibility in engineering them into different backgrounds as desired. Funding: Funding support from the USDA-NIFA Award No. 2016-70003-24775 and the Triticeae Coordinated Agricultural Project (T-CAP) awarded CB.