Grass Genetics Group
The Grass Genetics group focuses on understanding basic grass cell wall biology using rice as a model system. Both forward and reverse genetic approaches are being used to determine the function of genes involved in cell wall biosynthesis and modification.
To predict the biological functions of members of large gene families in the grasses, we have: (1) developed phylogenomic databases for rice kinases, glycosyltransferases (GTs), glycosyl hydrolases (GHs), transcription factors, and transporters; and, (2) demonstrated the application of these databases for assessing gene function. These databases present genomic, transcriptomic, and proteomic data in a phylogenetic data context and are publicly available (http://indica.ucdavis.edu/research/phylomics-1).
These databases have facilitated the identification and characterization of a set of high priority candidate genes for functional analysis. Most notably, we are focusing on grass-diverged GTs and acyltransferases that are unique to the grasses and that cannot be studied using dicot model systems such as Arabidopsis or poplar.
Figure 1. A mutant with decreased ferulic acid and no growth developmental defects. The reduction of ferulates in grass cell walls is an important goal as it reduces ferulate inhibition in fuels fermentations.
Figure 2. A mutant with decreased arabinoxylan content and increased saccharification efficiency.
We are also carrying two forward genetic screens to identify mutants with altered cell wall monosaccharide composition and enzymatic saccharification, respectively. For this approach, we have successfully generated a fast-neutron mutant population, developed and validated mutant screen protocols and begun screening 100,000 samples.
Figure 3. Forward genetic mutant screen strategy to identify mutants with altered cell wall composition and with changes in saccharification efficiency.
We have started sequencing the switchgrass genome in close collaboration with the Joint Genome Institute, Clemson University, Bioenergy Science Center, and Hudson Alpha.
