Immunological Approaches to Biomass Characterization and Utilization

Abstract

Plant biomass is the major renewable feedstock resource for sustainable generation of alternative transportation fuels to replace fossil carbon-derived fuels. Lignocellulosic cell walls are the principal component of plant biomass. Hence, a detailed understanding of plant cell wall structure and biosynthesis is an important aspect of bioenergy research. Cell walls are dynamic in their composition and structure, varying considerably among different organs, cells, and developmental stages of plants. Hence, tools are needed that are highly efficient and broadly applicable at various levels of plant biomass-based bioenergy research. The use of plant cell wall glycan-directed probes has seen increasing use over the past decade as an excellent approach for the detailed characterization of cell walls. Large collections of such probes directed against most major cell wall glycans are currently available worldwide. The largest and most diverse set of such probes consists of cell wall glycan-directed monoclonal antibodies (McAbs). These McAbs can be used as immunological probes to comprehensively monitor the overall presence, extractability, and distribution patterns among cell types of most major cell wall glycan epitopes using two mutually complementary immunological approaches, glycome profiling (an in vitro platform) and immunolocalization (an in situ platform). Significant progress has been made recently in the overall understanding of plant biomass structure, composition, and modifications with the application of these immunological approaches. This review focuses on such advances made in plant biomass analyses across diverse areas of bioenergy research.

A cell wall reference profile for Miscanthus bioenergy crops highlights compositional and structural variations associated with development and organ origin

“…Moreover, a large and diverse set of plant glycan‐directed monoclonal antibodies (mAbs) was used to monitor changes in matrix glycan distribution, structure and extractability. This suite of molecular probes possesses enough variability to allow the identification of most classes of noncellulosic plant cell wall polysaccharides (Pattathil et al ., , ). For the first time, this array of glycan‐directed mAbs was used to comprehensively characterize variations in the cell wall glycome of miscanthus across different harvests, organs and genotypes, to generate a representative reference profile for miscanthus cell wall biomass.…”

Monitoring Polysaccharide Dynamics in the Plant Cell Wall

“…Another potential disadvantage is that the FP domain may interfere with the ligand-binding site of the CBM (Knox, 2012). Regardless of the presence of FP tags, binding of a CBM or any other polysaccharide-directed mAbs provides limited quantitative information; an epitope may be found in multiple polymers, or it could be masked by its neighbors or hidden by an altered conformation of the target polysaccharide (Pattathil et al, 2015). Despite these issues, proteinaceous probes such as CBMs provide an unprecedented view of the occurrence of wall polysaccharides.…”

Branched Pectic Galactan in Phloem-Sieve-Element Cell Walls: Implications for Cell Mechanics

“…Monoclonal antibodies (MAbs) are the most effective molecular tools to-date to explore and understand cell wall heterogeneity in cell and tissue contexts (Knox 2008;Pattathil et al, 2015;Torode et al, 2016). Pectic HG and pectic RG-I epitopes are widely distributed and have been related to cell dynamics influencing cell growth and cell adhesion (Knox 2008;Willats et al, 2001a) but are rarely specific to cell types across a wide range of species.…”