Functional genomics of wood formation and phenolic metabolism, tree growth and stress response

A major thrust of our research concerns phenylpropanoid metabolism as it impacts “resource allocation” of trees during growth, wood formation, stress responses and environmental interactions. Wood formation in particular, interfaces with numerous cellular processes and metabolic pathways, and represents a fascinating biological model system from which advances in basic science can boost the economic value of trees. Improved understanding of the molecular mechanisms underpinning tree fitness and biomass productivity is expected to have significant impact on both plantation and ecosystem management, as well as environmental health.

Current research efforts focus on phenylpropanoid carbon allocation, and the regulation of competing branchways for biosynthesis of lignin, phenolic glycosides (PGs), flavonoid-derived condensed tannins (CTs) and other phenolic derivatives. CTs and PGs play important roles in defense and stress management among Salicaceae (e.g., poplars and willows), and together with lignin, represent a large carbon sink that can account for more than 50% of leaf biomass in these species. Their potential effects on tree growth, fitness, and wood quality, and their documented impacts on ecosystem dynamics are the driving force behind this line of research into the molecular regulation of phenylpropanoid metabolism. Additional research projects examine one-carbon metabolism and cytoskeletal regulation of cellulose microfibril deposition during wood formation. A suite of wood cell or fiber-specific promoters are being characterized for utility in genetic engineering of fiber properties.  We are also investigating alternative splicing as a critical factor in shaping the transcriptions of wood species.