Research Highlights

In this study, we used chemical genomics (CG) to identify the mechanisms of GVL toxicity to fermentative microbes. We identified gene deletions that confer sensitivity or tolerance to the solvent and then used this knowledge to engineer a xylose-fermenting yeast strain with improved tolerance to GVL and enhanced conversion of sugars to biofuel.

Many bacteria contain enzymes with the potential to convert renewable carbon sources into substitutes for compounds derived from petroleum. For example, the β-etherase pathway present in sphingomonad bacteria could cleave the abundant β-ether bonds in plant lignin, releasing a bio-based source of aromatic compounds for the chemical industry. In this study, GLBRC researchers demonstrated biodegradation of lignin polymers using a minimal set of β-etherase pathway enzymes.

We showed that Canary Island date palm (Phoenix canariensis) lignification uses an unprecedented range of monolignol conjugates, the distribution of which varies depending on the tissue region, indicating that they may play specific roles in the cell walls in these tissues and/or in the plant’s defense system.

In this study we characterized the impacts of biofuel cropping systems on soil microbial communities, finding that these communities were strikingly different depending on soil depth.

In this study, we further characterized a mutant gene (wri1-1) in the plant Arabidopsis that leads to strong reduction in seed oil content. We also identified a primary root defect and confirmed altered homeostasis in auxin, a growth regulator that plays an important role in plant development.

In this study, we identified flowering time gene candidates that could be employed to manipulate flowering time in upland, cold-tolerant switchgrass cultivars, with the goal of increasing total biomass yield for these northern accessions.

In this study, we tested Zip-lignin poplar vs. wild-type hybrid poplar to determine if Zip-lignin’s strategic lignin modifications, specifically engineered to reduce recalcitrance, enhance chemical pulping efficiencies. As predicted, Zip-lignin poplar demonstrated improved processing.

Assessing and predicting field-scale soil N2O (nitrous oxide) emissions remains imprecise because much of N2O production occurs within very small soil volumes called “hotspots.” In this study, we found that water absorption by plant residue creates unique conditions that can result in accelerated N2O emissions.

Recent discoveries indicate that lignification is a flexible mechanism and that plants are capable of using a variety of phenolic compounds for the formation of lignin polymers. In this study, we report the occurrence of a new class of polyphenolic compounds – hydroxystilbenes – the second such class arising from outside the monolignol biosynthetic pathway, in the lignins of palm fruit endocarps.

Stem length is a key trait for various sorghum genotypes, impacting biomass yield, plant architecture, and other important crop features. In this study, we identified the gene encoded by Dw2, a locus known to affect stem internode length; this gene encodes a protein kinase homologous to a member of the AGC protein kinase family in the plant Arabidopsis.