Lignin is a major impediment in the deconstruction of plant biomass to its soluble monomeric constituents. Modification of the lignin biosynthetic pathway has proven to be an effective means of reducing biomass recalcitrance but can often result in impaired growth. Successful examples of “designer” biomass include introducing monolignol ferulate conjugates into lignin backbone to allow readily breakdown under mild alkaline condition. Genes, such as feruloyl–coenzyme A (CoA) monolignol transferase (FMT) and p-Coumaroyl-CoA monolignol transferase (PMT), have been introduced into poplar or Arabidopsis and further confirmed the incorporation of monolignol ferulates into the lignin polymer in the FMT and PMT transgenic plants by a series of analytical methods. In order to evaluate the deconstructibility of the lignin-modified biomass, it is critical to understand the fine chemistry changes in situ, as well as the location and concentration of these conjugates in the cell walls of these transgenic plants. To this end, we have developed hyperspectral stimulated Raman scattering (hsSRS) methods using femtosecond or picosecond laser systems, which allow us to map the chemical changes in planta using lignin conjugated α–β carbon double bonds as the proxy. We found unique shifts between 1400 – 1750 cm-1 in their Raman spectra due to the conjugation of the double bond and an associated ester carbonyl group, and we are able to quantify the chemical concentration in situ at the nanometer scale in the cell walls of both FMT and PMT mutants. In addition, imaging of the cell wall ultrastructure in the transgenic plants have shown significant increase of accessible areas to the cellulases, which may be beneficial to the chemical penetration during pretreatment and substrate accessibility during enzymatic hydrolysis. Our study suggests that both physical and chemical modification of the plant cell wall could contribute to the observed improvements in sugar yields during biomass conversion processes.

Non-destructive imaging of lignin chemistry in plant cell wall using hyperspectral stimulated Raman scattering microscopy

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.