Limits...
Insights into plant cell wall structure, architecture, and integrity using glycome profiling of native and AFEXTM-pre-treated biomass.

Pattathil S, Hahn MG, Dale BE, Chundawat SP - J. Exp. Bot. (2015)

Bottom Line: For most biomass types analysed, such loosening was also evident for other major non-cellulosic components including subclasses of pectin and xyloglucan epitopes.The studies also demonstrate that AFEX™ pre-treatment significantly reduced cell wall recalcitrance among diverse phylogenies (except softwoods) by inducing structural modifications to polysaccharides that were not detectable by conventional gross composition analyses.It was found that monitoring changes in cell wall glycan compositions and their relative extractability for untreated and pre-treated plant biomass can provide an improved understanding of variations in structure and composition of plant cell walls and delineate the role(s) of matrix polysaccharides in cell wall recalcitrance.

View Article: PubMed Central - PubMed

Affiliation: Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA siva@ccrc.uga.edu shishir.chundawat@rutgers.edu.

No MeSH data available.


Related in: MedlinePlus

Heat map analyses of the relative abundance of major non-cellulosic cell wall glycan epitopes in oxalate extracts from eight phylogenetically diverse plant biomasses with or without AFEX™ pre-treatment. Oxalate extracts were prepared from cell walls isolated from diverse classes of plant biomass as explained in the Materials and Methods. The extracts were subsequently screened by ELISA using a comprehensive suite of cell wall glycan-directed mAbs. Binding response values are depicted as heat maps with a black–red–bright yellow colour scheme, where bright yellow represents the strongest binding and black no binding. The dotted boxes outline sets of antibodies whose binding signals were used for the scatter plot analyses shown in Fig. 2. The amount of carbohydrate material recovered per gram of cell wall is depicted in the bar graphs (purple) above the heat maps. The panel on the right-hand side of the heat map shows the groups of mAbs based on the class of cell wall glycan they each recognize.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4493783&req=5

Figure 1: Heat map analyses of the relative abundance of major non-cellulosic cell wall glycan epitopes in oxalate extracts from eight phylogenetically diverse plant biomasses with or without AFEX™ pre-treatment. Oxalate extracts were prepared from cell walls isolated from diverse classes of plant biomass as explained in the Materials and Methods. The extracts were subsequently screened by ELISA using a comprehensive suite of cell wall glycan-directed mAbs. Binding response values are depicted as heat maps with a black–red–bright yellow colour scheme, where bright yellow represents the strongest binding and black no binding. The dotted boxes outline sets of antibodies whose binding signals were used for the scatter plot analyses shown in Fig. 2. The amount of carbohydrate material recovered per gram of cell wall is depicted in the bar graphs (purple) above the heat maps. The panel on the right-hand side of the heat map shows the groups of mAbs based on the class of cell wall glycan they each recognize.

Mentions: The glycome profiling data are organized by cell wall extract for untreated biomass and biomass pre-treated under three regimes of AFEX™, namely low, medium, and severe (see the Materials and Methods for details) for all eight plant species analysed. Examination of the heat maps resulting from the antibody screening of the oxalate-solubilized material (first extraction stage) (Fig. 1) shows that increasing AFEX™ pre-treatment severity significantly enhanced the presence of epitopes recognized by the xylan-4 to xylan-7 groups of mAbs (that can recognize both unsubstituted homoxylans and substituted xylans such as glucuronoxylans or arabinoxylans; Schmidt et al., 2015) for all plant species examined (Fig. 1; yellow dotted block). In the case of monocot grasses, a similar enhancement in the oxalate extracts was also observed for epitopes recognized by the xylan-3 group of mAbs. Scatter plot analyses of the glycome profiling data (Fig. 2) substantiated these conclusions as an enhanced abundance of xylan epitopes was observed in the oxalate extracts in all medium AFEX™ severity pre-treated biomass samples compared with untreated controls. For other biomass types, enhanced binding of xyloglucan-directed mAbs to the oxalate extracts from the most severe AFEX™ regimes was evident (Fig. 1; white dotted block). Supporting this observation, scatter plot analyses for biomass samples pre-treated with the medium AFEX™ severity regime indicated enhanced extractability of xyloglucan epitopes in all cases except for the two gymnosperms, Douglas fir and loblolly pine, where no obvious trends were apparent. These results suggest that AFEX™ pre-treatment leads to enhanced extractability of xyloglucan epitopes only in biomass materials of angiosperm origin. Scatter plot analyses of the pectin and arabinogalactan epitopes (those recognized by the homogalacturonan- and rhamnogalacturonan-I-backbone groups and the rhamnogalacturonan-I/arabinogalactan and various arabinogalactan groups of mAbs, respectively) present within the oxalate extracts exhibited similar trends to the case of xyloglucan epitopes, with enhanced abundance of all of these epitopes in oxalate extracts of pre-treated samples for all biomasses except the two gymnosperms, which showed both increased and decreased extractabilities of pectin and arabinogalactan epitopes as a result of AFEX™ pre-treatment; loblolly pine, in particular, showed a large number of arabinogalactan epitopes with reduced extractability by oxalate (Fig. 2), especially for the most severe pre-treatment regime (Fig. 1). In general, oxalate extracted more material from the walls of monocots and dicots than from the walls of gymnosperms (Fig. 1, bar graphs); the herbaceous dicot biomasses yielded the most oxalate-extractable material.


Insights into plant cell wall structure, architecture, and integrity using glycome profiling of native and AFEXTM-pre-treated biomass.

Pattathil S, Hahn MG, Dale BE, Chundawat SP - J. Exp. Bot. (2015)

Heat map analyses of the relative abundance of major non-cellulosic cell wall glycan epitopes in oxalate extracts from eight phylogenetically diverse plant biomasses with or without AFEX™ pre-treatment. Oxalate extracts were prepared from cell walls isolated from diverse classes of plant biomass as explained in the Materials and Methods. The extracts were subsequently screened by ELISA using a comprehensive suite of cell wall glycan-directed mAbs. Binding response values are depicted as heat maps with a black–red–bright yellow colour scheme, where bright yellow represents the strongest binding and black no binding. The dotted boxes outline sets of antibodies whose binding signals were used for the scatter plot analyses shown in Fig. 2. The amount of carbohydrate material recovered per gram of cell wall is depicted in the bar graphs (purple) above the heat maps. The panel on the right-hand side of the heat map shows the groups of mAbs based on the class of cell wall glycan they each recognize.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4493783&req=5

Figure 1: Heat map analyses of the relative abundance of major non-cellulosic cell wall glycan epitopes in oxalate extracts from eight phylogenetically diverse plant biomasses with or without AFEX™ pre-treatment. Oxalate extracts were prepared from cell walls isolated from diverse classes of plant biomass as explained in the Materials and Methods. The extracts were subsequently screened by ELISA using a comprehensive suite of cell wall glycan-directed mAbs. Binding response values are depicted as heat maps with a black–red–bright yellow colour scheme, where bright yellow represents the strongest binding and black no binding. The dotted boxes outline sets of antibodies whose binding signals were used for the scatter plot analyses shown in Fig. 2. The amount of carbohydrate material recovered per gram of cell wall is depicted in the bar graphs (purple) above the heat maps. The panel on the right-hand side of the heat map shows the groups of mAbs based on the class of cell wall glycan they each recognize.
Mentions: The glycome profiling data are organized by cell wall extract for untreated biomass and biomass pre-treated under three regimes of AFEX™, namely low, medium, and severe (see the Materials and Methods for details) for all eight plant species analysed. Examination of the heat maps resulting from the antibody screening of the oxalate-solubilized material (first extraction stage) (Fig. 1) shows that increasing AFEX™ pre-treatment severity significantly enhanced the presence of epitopes recognized by the xylan-4 to xylan-7 groups of mAbs (that can recognize both unsubstituted homoxylans and substituted xylans such as glucuronoxylans or arabinoxylans; Schmidt et al., 2015) for all plant species examined (Fig. 1; yellow dotted block). In the case of monocot grasses, a similar enhancement in the oxalate extracts was also observed for epitopes recognized by the xylan-3 group of mAbs. Scatter plot analyses of the glycome profiling data (Fig. 2) substantiated these conclusions as an enhanced abundance of xylan epitopes was observed in the oxalate extracts in all medium AFEX™ severity pre-treated biomass samples compared with untreated controls. For other biomass types, enhanced binding of xyloglucan-directed mAbs to the oxalate extracts from the most severe AFEX™ regimes was evident (Fig. 1; white dotted block). Supporting this observation, scatter plot analyses for biomass samples pre-treated with the medium AFEX™ severity regime indicated enhanced extractability of xyloglucan epitopes in all cases except for the two gymnosperms, Douglas fir and loblolly pine, where no obvious trends were apparent. These results suggest that AFEX™ pre-treatment leads to enhanced extractability of xyloglucan epitopes only in biomass materials of angiosperm origin. Scatter plot analyses of the pectin and arabinogalactan epitopes (those recognized by the homogalacturonan- and rhamnogalacturonan-I-backbone groups and the rhamnogalacturonan-I/arabinogalactan and various arabinogalactan groups of mAbs, respectively) present within the oxalate extracts exhibited similar trends to the case of xyloglucan epitopes, with enhanced abundance of all of these epitopes in oxalate extracts of pre-treated samples for all biomasses except the two gymnosperms, which showed both increased and decreased extractabilities of pectin and arabinogalactan epitopes as a result of AFEX™ pre-treatment; loblolly pine, in particular, showed a large number of arabinogalactan epitopes with reduced extractability by oxalate (Fig. 2), especially for the most severe pre-treatment regime (Fig. 1). In general, oxalate extracted more material from the walls of monocots and dicots than from the walls of gymnosperms (Fig. 1, bar graphs); the herbaceous dicot biomasses yielded the most oxalate-extractable material.

Bottom Line: For most biomass types analysed, such loosening was also evident for other major non-cellulosic components including subclasses of pectin and xyloglucan epitopes.The studies also demonstrate that AFEX™ pre-treatment significantly reduced cell wall recalcitrance among diverse phylogenies (except softwoods) by inducing structural modifications to polysaccharides that were not detectable by conventional gross composition analyses.It was found that monitoring changes in cell wall glycan compositions and their relative extractability for untreated and pre-treated plant biomass can provide an improved understanding of variations in structure and composition of plant cell walls and delineate the role(s) of matrix polysaccharides in cell wall recalcitrance.

View Article: PubMed Central - PubMed

Affiliation: Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA siva@ccrc.uga.edu shishir.chundawat@rutgers.edu.

No MeSH data available.


Related in: MedlinePlus