Functional Informatics of Cellulose Synthase Genes in Wheat

Cell walls are the most abundant renewable carbon source on earth. They play a major role in providing physical strength and innate immunity to plants. Plant cell walls are mainly made up of cellulose along with different proportions of lignin and hemicelluloses.  Wheat, a major staple food of the world, which also produces large amount of cellulosic straw, is currently an important target crop for production of bioproducts. Cellulose, a major component of the cellulosic component is synthesised by a multi-meric protein complex that form a hexameric rosette-like structure in plasma membrane. Catalytic subunits of these complexes are encoded by a group of genes called CesA (cellulose synthase). Many CesA genes have been discovered in species such as Arabidopsis, rice, maize and barley. However, limited information is available about CesA genes in wheat. We have identified 8 CesA genes from wheat (TaCesAs) and performed structural, functional, and evolutionary analysis of these genes involved in primary cell wall (PCW) and secondary cell wall (SCW) synthesis.  Our analysis identified conserved motifs specific to PCW and SCW. A monocot specific, 3-dimentional structure of a zinc finger domain within the TaCESA protein was also predicted using ring finger domain of cellulose synthase catalytic subunit of A. thaliana. All PCW-TaCESA proteins revealed identical active sites, but SCW-CESAs showed variability except TaCESA8. This information will allow us to develop a deeper understanding of CSC assembly in higher plants including improvement of cellulosic biofuels through breeding efforts.