The lignification of the leaf vein bundle sheath (BS) has been observed in many species and would reduce conductance from xylem to mesophyll. We hypothesized that lignification of the BS in lower-order veins would provide benefits for water delivery through the vein hierarchy but that the lignification of higher-order veins would limit transport capacity from xylem to mesophyll and leaf hydraul...

Zinnia elegans constitutes one of the most useful model systems for studying xylem differentiation, which simultaneously involves secondary cell wall synthesis, cell wall lignification, and programmed cell death. Likewise, the in vitro culture system of Z. elegans has been the best characterized as the differentiation of mesophyll cells into tracheary elements allows study of the biochemistry a...

We examined the relationship between β-glucosi-dase and peroxidase activities and xylem lignification in the stems of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) Karst.) and silver birch (Betula pendula Roth) during the 1999 growing season. Examination of stem cross sections stained with safranin and Alcian blue for lignin and cellulose, respectively, indicated that radial...

The lignification process in poplar tension wood lignified cell wall layers, specifically the S(1) and S(2) layers and the compound middle lamella (CML), was analysed using ultraviolet (UV) and transmission electron microscopy (TEM). Variations in the thickness of the gelatinous layer (G-layer) were also measured to clarify whether the lignified cell wall layers had completed their lignificatio...

Lignification limits grass cell-wall digestion by herbivores. Lignification is spatially and temporally regulated, and lignin characteristics differ between cell walls, plant tissues, and plant parts. Grass lignins are anchored within walls by ferulate and diferulate cross-links, p-coumarate cyclodimers, and possibly benzyl ester and ether cross-links. Cell-wall degradability is regulated by li...

Arabidopsis ecotype Columbia (Col-0) seedlings, transformed with a phenylalanine ammonia-lyase 1 promoter (PAL1)-[beta]-glucuronidase (GUS) reporter construct, were inoculated with virulent and avirulent isolates of Peronospora parasitica. The PAL1 promoter was constitutively active in the light in vascular tissue but was induced only in the vicinity of fungal structures in the incompatible int...

Lignin is a critical structural component of plants, providing vascular integrity and mechanical strength. Lignin precursors (monolignols) must be exported to the extracellular matrix where random oxidative coupling produces a complex lignin polymer. The objectives of this study were twofold: to determine the timing of lignification with respect to programmed cell death and to test if nonlignif...

To understand the metabolite dynamics and genetic regulatory mechanism of apricot shell, a typical endocarp, before after lignification are unknown, we investigated differences endocarp ‘Youyi,’ popular kernel-using cultivar, using ultra-performance liquid chromatography tandem mass spectrometry strategy. The thickness increased rapidly from 8 to 37 days flowering (DAF) lignin deposition began ...

Lignin is a key structural component of plant cell walls that provides rigidity, strength, and resistance against microbial attacks. This hydrophobic polymer also serves a crucial role in water transport. Despite its abundance and essential functions, several aspects of lignin biosynthesis and deposition remain cryptic. Lignin precursors are known to be synthesized in the cytoplasm by complex b...