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Atypical lignification in eastern leatherwood ( Dirca palustris )
Author(s) -
Mottiar Yaseen,
Gierlinger Notburga,
Jeremic Dragica,
Master Emma R.,
Mansfield Shawn D.
Publication year - 2020
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.16394
Subject(s) - lignin , xylem , cell wall , botany , biopolymer , coniferyl alcohol , polysaccharide , trichome , chemistry , biology , polymer , biochemistry , organic chemistry
Summary Lignin is a complex phenolic biopolymer found mainly in the secondary cell walls of vascular plants, where it contributes to mechanical strength, water conduction, and plant defence. We studied the lignin of eastern leatherwood ( Dirca palustris ) because this slow‐growing woody shrub is known for its flexible stems. Various analytical techniques and microscopy methods were employed to examine the composition and distribution of lignin and structural polysaccharides in leatherwood xylem in comparison with trembling aspen ( Populus tremuloides ) and white spruce ( Picea glauca ). We found that leatherwood has low overall levels of lignin, a high syringyl lignin content, and a unique distribution of lignin. Most remarkably, the cell corners and middle lamellae remain unlignified in mature xylem. These findings help explain the flexibility of leatherwood and also call into question the classical model of lignification, which purports that lignin polymerization begins in the cell corners and middle lamellae. This atypical lignification regime vividly illustrates the diversity in plant secondary cell wall formation that abounds in nature and casts leatherwood as a new model for the study of lignin biogenesis.