Wood formation occurs via cell division, primary cell wall and secondary wall formation, and programmed cell death in the vascular cambium. Transcriptional profiling of secondary xylem differentiation is essential for understanding the molecular mechanisms underlying wood formation. Differential gene expression in secondary xylem differentiation of Populus has been previously investigated using...

The hydrophobic cell wall polymer lignin is deposited in specialized cells to make them impermeable to water and prevent cell collapse as negative pressure or gravitational force is exerted. The variation in lignin subunit composition that exists among different species, and among different tissues within the same species suggests that lignin subunit composition varies depending on its precise ...

The primary inflorescence stem of Arabidopsis thaliana is rich in lignified cell walls, in both vascular bundles and interfascicular fibres. Previous gene expression studies demonstrated a correlation between expression of phenylpropanoid biosynthetic genes and a subset of genes encoding ATP-binding cassette (ABC) transporters, especially in the ABCB/multi-drug resistance/P-glycoprotein (ABCB/M...

Chloroplast number per cell is a frequently examined quantitative anatomical parameter, often estimated by counting chloroplast profiles in two-dimensional (2D) sections of mesophyll cells. However, a mesophyll cell is a three-dimensional (3D) structure and this has to be taken into account when quantifying its internal structure. We compared 2D and 3D approaches to chloroplast counting from di...

Deposition of lignified secondary cell walls in plants involves a major commitment of carbon skeletons in both the form of polysaccharides and phenylpropanoid constituents. This process is spatially and temporally regulated by transcription factors, including a number of MYB family transcription factors. MYB75, also called PRODUCTION OF ANTHOCYANIN PIGMENT1, is a known regulator of the anthocya...

-Cross-linking of arabinoxylans by ferulate dehydrodimers and incorporation of feruloylated arabinoxylans into lignin were modelled with maize walls (Zea mays cv Black Mexican) containing 5.3-18.0 mg g~ of total ferulates. The proportion of dehydrodimers to total ferulates increased from ca 20 to 45% when dilute hydrogen peroxide was added to walls containing bound peroxidase. About 45% of the ...

The formation and structure of asyncytium induced by the potato cyst-nematode {Heterodera rostockiensis Woll.) in potato roots is described. At the permanent feeding site of the nematode larva, usually in the root cortex, the larva pierces a cell with its mouth stylet and injects saliva. Cell wall dissolution occurs to incorporate neighbouring cells into a syncytium. A column of cells is incorp...

Plants are built of various specialized cell types that differ in their cell wall composition and structure. The cell walls of certain tissues (xylem, sclerenchyma) are characterized by the presence of the heterogeneous lignin polymer that plays an essential role in their physiology. This phenolic polymer is composed of different monomeric units - the monolignols - that are linked together by s...

To gain insights into the forage morphological and anatomical characteristics in a silvopastoral system (SPS) with Bolsa de Pastor (Zeyheria tuberculosa) palisadegrass ‘Marandu’ (Urochloa brizantha) monoculture (MONO). The SPS was established through natural regeneration of tree species. Treatments were MONO distributed completely randomized design six replicates repeated measures harvest perio...

Terminal differentiation of many vascular cells involves cell wall changes. Cells first elongate their primary wall, then lay down a lignified secondary wall, which is often followed by digestion of the primary wall. Expansins are wall proteins that regulate wall changes, but little is known about the specific functions of the many individual expansin isoforms. An in vitro cell culture of synch...