“…Lignin exists within the plant cell matrix, interfacing with both hemicellulose and cellulose ( Foston et al, 2012 , Figure 1B ). Solution-state NMR in combination with MS, which relies on swelling ball-milled plant cell walls with deuterated solvents, provides detailed information on the types, functionalization, abundance of lignin linkages present, and linkage size ( Kim and Ralph, 2010 ; Pu et al, 2011 ; Balakshin and Capanema, 2015 ; Foston et al, 2016 ; Bergs et al, 2020 ; Hyväkkö et al, 2020 ; Zhang et al, 2021b ). However, due to the necessity for drying, mechanical treatment, dissolution, or solvent extraction in these techniques, they do not report on recalcitrance in the intact (native) secondary plant cell wall.…”