Example：10.1021/acsami.1c06204 or Chem. Rev., 2007, 107, 2411-2502
ToF-SIMS imaging reveals that p-hydroxybenzoate groups specifically decorate the lignin of fibres in the xylem of poplar and willow Holzforschung (IF2.393), Pub Date : 2021-05-01, DOI: 10.1515/hf-2020-0130 Robyn E. Goacher, Yaseen Mottiar, Shawn D. Mansfield
Esterified phenolics occur as γ -linked lignin acylations in many plant taxa but little is known about the distribution or function of such groups. In the family Salicaceae, p -hydroxybenzoate groups are present in the lignin of poplars ( Populus spp.) and willows ( Salix spp.). In this study, the distribution of cell wall-bound p -hydroxybenzoate was examined in different tissue and cell types of poplar and willow trees. This analysis showed that p -hydroxybenzoate groups were most prevalent in juvenile stems, and were elevated in tension wood and following nitrogen fertilisation. Closer examination of stem cross-sections using time-of-flight secondary-ion mass spectrometry (ToF-SIMS) directly showed that p -hydroxybenzoate groups occur predominantly in the cell walls of fibres and are largely absent from vessel elements. These results point to a role for ester-linked groups in modifying the syringyl-rich lignin of fibres, perhaps to strengthen the cell walls of these structural elements or to increase lignification rates.