Research Highlights

To better understand the development of plant cell walls and to improve strategies for the valorization of lignocellulosics, we identified and quantified 12 degradation products released by lignin depolymerization using newly synthesized standards.

This study tested whether we can alter cell wall attributes and plant development by augmenting the available soluble sucrose pools. To this end, we overexpressed an exogenous galactinol synthase to alter carbon allocation in hybrid poplar and then examined the effects on plant growth, carbohydrate and lignin content and composition, xylem properties, wood physical characteristics, and transcript abundance of differentially expressed genes.

The degradation of cellulose, the principal component of plant cell walls, is critical to ecosystem functioning and the global carbon cycle. The primary drivers of plant biomass deconstruction are fungi and bacteria found in the soil or associated with plant-eating eukaryotes.

Native perennial grasslands, which can be planted on marginal lands, are a potential feedstock source for lignocellulosic biofuel production. And yet more information is needed to understand how management practices such as frequency or timing of harvesting can affect their productivity and community composition.

By studying a naturally silenced maize mutant defective in chalcone synthase, a key enzyme involved in the biosynthesis of flavonoids, we demonstrated that levels of tricin-related flavonoids were significantly reduced, resulting in strongly reduced incorporation of tricin into the lignin polymer. These plants also had increased total lignin content and, consequently, demonstrated significantly reduced saccharification.

Adding cover crops to annual maize production systems did not enhance predator communities. And predation levels remained low in comparison to perennial bioenergy crops.

OptSSeq (Optimization by Selection and Sequencing) is a newly developed approach to identifying optimally balanced enzyme levels in synthetic biofuel production pathways. This method couples selection of enzyme expression levels with high-throughput gene sequencing to track enrichment of gene expression elements from a combinatorial library.

To explore the genetic architecture of flowering time, we developed a recombinant inbred line population from a cross between two diverse accessions of the grass Brachypodium distachyon that have different flowering behavior. We then used a genotyping-by-sequencing approach to identify six quantitative trait locis that control differences in flowering time.

We performed genome-wide association studies to characterize the genetic architecture and genes underlying flowering time regulation in switchgrass. We then identified association with flowering time at multiple loci, including in a homolog of the gene FLOWERING LOCUS T and in a locus containing the gene TIMELESS, a homolog of a key circadian regulator in animals.

We collected sorghum stem RNA-seq transcriptome profiles and composition data for approximately 100 days of development beginning at floral initiation. Our analysis identified more than 200 differentially expressed genes involved in stem growth, cell wall biology, and sucrose accumulation.