Genome-Wide SNP Association, -Omics and Genetic Transformation Approaches Inform Cellulose Biosynthesis Pathway in a Bioenergy Plant Model

A cross-cutting study designed to identify new cellulose biosynthesis pathway players in Populus, a model bioenergy plant, has revealed several promising candidate genes. The study involved 1) transcriptomics and proteomics characterization of developmental and physiological contexts of enhanced cellulose production, 2) bioinformatics-based analyses of co-expression networks in Populus and Arabidopsis, and 3) a genome-wide SNP association study involving a population of 1000 Populus trichocarpa individuals. High-priority candidate gene targets were identified at the intersection of these studies. Transgenic Populus plants modified in selected genes from KOG categories of signaling regulation, DNA transcription and cell wall metabolism were phenotypically characterized using a broad suit of cell wall and biomass analysis tools. Evidence in support of role for a putative signaling protein as a new candidate cellulose pathway gene will be provided as an example of success with the combinatorial genetic and genomics approach applied here.