Plants precisely control lignin deposition in spiral or annular secondary cell wall domains during protoxylem tracheary element (TE) development. Because TEs function to transport water within rapidly elongating tissues, it is important that restricted the walls order preserve plasticity of adjacent primary domains. The Arabidopsis (Arabidopsis thaliana) inducible VASCULAR NAC DOMAIN7 (VND7) TE differentiation system permits use mutant backgrounds, fluorescent protein tagging, and...

Summary Genetic evidence links the Arabidopsis MONOPTEROS ( MP ) and PIN‐FORMED1 PIN1 genes to patterning of leaf veins. To elucidate their potential functions interactions in this process, we have assessed dynamics expression during vascular primordia. Both undergo a dynamic process gradual refinement into files one two cells wide before overt differentiation. The subcellular distribution is also gradually refined from non‐polar isodiametric strongly polarized elongated procambial provides...

The primary inflorescence stem of Arabidopsis thaliana is rich in lignified cell walls, both vascular bundles and interfascicular fibres. Previous gene expression studies demonstrated a correlation between phenylpropanoid biosynthetic genes subset encoding ATP-binding cassette (ABC) transporters, especially the ABCB/multi-drug resistance/P-glycoprotein (ABCB/MDR/PGP) ABCG/pleiotropic drug resistance (ABCG/PDR) subfamilies. objective this study was to characterize these ABC transporters terms...

Lignin is a critical structural component of plants, providing vascular integrity and mechanical strength. precursors (monolignols) must be exported to the extracellular matrix where random oxidative coupling produces complex lignin polymer. The objectives this study were twofold: determine timing lignification with respect programmed cell death test if nonlignifying xylary parenchyma cells can contribute tracheary elements fibers. This demonstrates that deposition not exclusively postmortem...

Abstract The TALE homeodomain transcription factor KNOTTED ARABIDOPSIS THALIANA7 (KNAT7) is part of a regulatory network governing the commitment to secondary cell wall biosynthesis Arabidopsis thaliana, where it contributes negative regulation this process. Here, we report that BLH6, BELL1-LIKE HOMEODOMAIN protein, specifically interacts with KNAT7, and interaction influences development. BLH6 transcriptional repressor, BLH6-KNAT7 physical enhances KNAT7 repression activities. overlapping...

Lignin, a critical phenolic polymer in secondary cell walls of plant cells, enables strength fibers and water transportation xylem vessel elements. Secreted enzymes, namely laccases (LACs) peroxidases (PRXs), facilitate lignin polymerization by oxidizing monomers (monolignols). Previous work Arabidopsis (

Lignin is an important phenolic biopolymer that provides strength and rigidity to the secondary cell walls of tracheary elements, sclereids, fibers in vascular plants. precursors, called monolignols, are synthesized exported wall where they polymerized into lignin by oxidative enzymes such as laccases peroxidases. In Arabidopsis thaliana, a peroxidase (PRX64) laccase (LAC4) shown localize differently within domains interfascicular fibers: PRX64 localizes middle lamella whereas LAC4...

Lignin, the second most abundant biopolymer, is a promising renewable energy source and chemical feedstock. A key element of lignin biosynthesis unknown: how do precursors (monolignols) get from inside cell out to wall where they are polymerized? Modeling indicates that monolignols can passively diffuse through lipid bilayers, but this has not been tested experimentally. We demonstrate significant monolignol diffusion occurs when laccases, which consume monolignols, present on one side...

Many land plants evolved tall and sturdy growth habits due to specialized cells with thick lignified cell walls: tracheary elements that function in water transport fibers structural support. The objective of this study was define how when diverse populations contribute lignin precursors, monolignols, secondary walls during lignification the Arabidopsis (Arabidopsis thaliana) inflorescence stem. Previous work demonstrated that, biosynthesis is suppressed fiber element thickened walls, become...

The secondary cell wall (SCW) of xylem vessel cells provides rigidity and strength that enables efficient water conduction throughout the plant. To gain insight into SCW deposition, we mutagenized Arabidopsis thaliana VASCULAR-RELATED NAC-DOMAIN7-inducible plant lines, in which ectopic protoxylem differentiation is synchronously induced. baculites mutant was isolated based on absence helical patterns ectopically-induced cells, mature plants exhibited an irregular (irx) phenotype plants. A...

Initiation of leaves at the flanks shoot apical meristem occurs sites auxin accumulation and pronounced expression auxin-inducible PIN-FORMED1 (PIN) genes, suggesting a feedback loop to progressively focus in concrete spots. Because PIN is regulated by response factor activity, including MONOPTEROS (MP), it appeared possible that MP affects leaf formation as positive regulator genes transport. Here, we analyze novel, completely leafless phenotype arising from simultaneous interference with...

Abstract Conifers possess an array of physical and chemical defences against stem‐boring insects. Stone cells provide a defence associated with resistance bark beetles weevils. In Sitka spruce ( Picea sitchensis ), abundance stone in the cortex apical shoots is positively correlated to white pine weevil Pissodes strobi ). We identified histological, biochemical molecular differences cell phenotype resistant (R) or susceptible (S) genotypes. R trees displayed significantly higher quantities...

Cellulose is a critical component of secondary cell walls and woody tissues plants. synthase (CESA) complexes (CSCs) produce cellulose as they move within the plasma membrane, extruding glucan chains into wall that coalesce crystallize fibrils. Here we examine COBRA-LIKE4 (COBL4), GPI-anchored protein on outer leaflet membrane required for normal deposition in walls. Characterization Arabidopsis (Arabidopsis thaliana) cobl4 mutant alleles called irregular xylem6, irx6-2 irx6-3, showed...

Dedicated lignocellulosic feedstock from grass crops for biofuel production is extensively increasing. However, the access to fermentable cell wall sugars by carbohydrate degrading enzymes impeded lignins. These complex polymers are made reactive oxidized monolignols in wall. Little known about laccase-mediated oxidation of grasses, and inactivation monolignol polymerization mechanism might be a strategy increase yield sugars. LACCASE5 LACCASE8 inactivated Brachypodium double mutant....

Summary Many plant genes are known to be involved in the development of cambium and wood, but how expression functional interaction these determine unique biology wood remains largely unknown. We used soc1ful loss function mutant – woodiest genotype otherwise herbaceous model Arabidopsis investigate interactions secondary growth (wood formation). Detailed anatomical observations stem combination with mRNA sequencing were assess transcriptome remodeling during xylogenesis wild‐type woody...

Based on mutant phenotypes the MONOPTEROS (MP)/Auxin Response Factor 5 (ARF5) gene acts in several developmental processes including leaf vein development. Since overlapping functions among ARF genes are common, we assessed related 3-8 and 19 for potential overlap expression during development using in-situ hybridization. Like MP/ARF5, ARF3 was expressed preprocambial procambial cells. ARF7 also cells, close to differentiation. ARF19 differentiating vessel elements. To assess if with have...

Abstract Lignin is a key secondary cell wall chemical constituent, and both barrier to biomass utilization potential source of bioproducts. The Arabidopsis transcription factors MYB58 MYB63 have been shown upregulate gene expression the general phenylpropanoid monolignol biosynthetic pathways. overexpression these genes also results in dwarfism. vascular integrity, soluble phenolic profiles, lignin, transcriptomes associated with MYB‐overexpressing lines were characterized. Plants high had...

Two isolates of Turnip mosaic virus (UK 1 and JPN 1), representative two different viral strains, induced differential alterations on secondary cell wall (SCW) development in Arabidopsis thaliana , suggesting cell-type specific effects these infections. These potential were analyzed inflorescence stems flowers infected plants, together with other possible cellular the Results obtained from macroscopic histochemical analyses showed that infection either significantly narrowed stem area, but...

Vascular tissues are of particular importance to terrestrial plants as they allow long-distance transport within the plant and also provide support for upright growth. Nowhere these traits more obvious than in tree species. Here we have evaluated role auxin differentiation primary secondary vascular a species, trembling aspen ( Populus tremuloides Michx). We found that partial inhibition resulted increased width numbers veins leaves. A similar overgrowth was observed during early stems. This...

Schuetz, M., Douglas, C., Samuels, L. and Ellis, B. 2014. Manipulating lignin deposition. Can. J. Plant Sci. 94: 1043–1049. Since represents one of most durable forms fixed carbon in plant biomass, we hypothesized that increasing root content for crops whose systems remained the soil after harvest would elevate total amount retained Canadian agroecosystems. The immediate goal this Greencrop project was, therefore, to gain a better understanding molecular mechanisms control deposition polymer...

Schuetz, M., Douglas, C., Samuels, L. and Ellis, B. 2014. Manipulating lignin deposition. Can. J. Plant Sci. 94: 1043-1049. Since represents one of most durable forms fixed carbon in plant biomass, we hypothesized that increasing root content for crops whose systems remained the soil after harvest would elevate total amount retained Canadian agroecosystems. The immediate goal this Greencrop project was, therefore, to gain a better understanding molecular mechanisms control deposition polymer...

Cannabis plants produce a spectrum of secondary metabolites, encompassing cannabinoids and more than 300 non-cannabinoid compounds. Among these, anthocyanins have important functions in also well documented health benefits. Anthocyanins are largely responsible for the red/purple color phenotypes plants. Although some well-known varieties display wide range pigmentation, genetic underpinnings anthocyanin biosynthesis not been characterized Cannabis. This study unveils diversity genes found...