Overexpression of xylan arabinosyltransferase genes to improve biomass digestibility in Setaria viridis

Abstract

The degradation of lignocellulosic material is very difficult due to its complex structure. The complex network of cross-links in cell walls can inhibit the digestion of cellulose, blocking enzymatic access to the biomass. Hence, theenzymatic and thermochemical treatment is essential for the degradation oflignocellulosic macromolecules into small subunits for further processing, making this process very costly. As the biomass recalcitrance is basicallyconferred by the cell wall composition, genetic modification of cell wall represents a powerful tool for the reduction of recalcitrance and, consequently, for the viability of the biofuel production process.Here, we propose the modification of the cell wall by overexpressing genes responsible for the coding of xylan arabinosyltransferases (XAT genes). These proteins incorporate arabinosyl residues into the hemicellulose portion of the cell wall matrix, and their increased production may change the cell wall structure, increasing the biomass digestibility. Thus, the aim of this proposal is analyzing the digestibility of biomass and to characterize in detail the cell wall composition of Setaria viridis plants overexpressing XAT genes. As such, we intend to contribute to the understanding of plant cell wall architecture, oscillation patterns and their biosynthesis. Theseinformation is valorous to accelerate the development of technologies for cellulosic ethanol production. (AU)