Lignins are complex phenylpropanoid polymers mostly associated with plant secondary cell walls. arise primarily via oxidative polymerization of the three monolignols, p -coumaryl, coniferyl, and sinapyl alcohols. Of two hydroxycinnamyl alcohols that represent incompletely methylated biosynthetic products (and not usually considered to be monolignols), 5-hydroxyconiferyl alcohol is now well established as incorporating into angiosperm lignins, but incorporation caffeyl has been shown. We...

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...

Lignin, a major component of lignocellulosic biomass, is crucial to plant growth and development but impediment efficient biomass utilization in various processes. Valorizing lignin increasingly realized as being essential. However, rapid condensation during acidic extraction leads the formation recalcitrant condensed units that, along with similar structural heterogeneity native lignin, drastically limits product yield selectivity. Catechyl (C-lignin), which essentially benzodioxane...

Lignins are phenylpropanoid polymers, derived from monolignols, commonly found in terrestrial plant secondary cell walls. We recently reported evidence of an unanticipated catechyl lignin homopolymer (C lignin) solely caffeyl alcohol the seed coats several monocot and dicot plants. previously identified seeds that possessed either C or traditional guaiacyl/syringyl (G/S) lignins, but not both. Here, we plants (Euphorbiaceae Cleomaceae) produce together with G/S lignins their coats....

A cDNA clone encoding the lignin-related enzyme caffeoyl CoA 3-O-methyltransferase (CCoAOMT) was isolated from a Pinus radiata library derived differentiating xylem. Suppression of PrCCoAOMT expression in P. tracheary element cultures affected lignin content and composition, resulting polymer containing p-hydroxyphenyl (H), catechyl (C) guaiacyl (G) units. Acetyl bromide-soluble assays revealed reductions up to 20% PrCCoAOMT-deficient transgenic lines. Pyrolysis-GC/MS 2D-NMR studies...

We have recently described a hitherto unsuspected catechyl lignin polymer (C-lignin) in the seed coats of Vanilla orchid and cacti one genus, Melocactus (Chen et al., Proc. Natl. Acad. Sci. USA. 2012, 109, 1772-1777.). now determined types 130 different cactus species. Lignin vegetative tissues is normal guaiacyl/syringyl (G/S) type, but members most genera within subfamily Cactoidae possess coat novel C-type only, which we show homopolymer formed by endwise β-O-4-coupling caffeyl alcohol...

Modifying lignin composition and structure is a key strategy to increase plant cell wall digestibility for biofuel production. Disruption of the genes encoding both cinnamyl alcohol dehydrogenases (CADs), including CADC CADD, in Arabidopsis thaliana results atypical incorporation hydroxycinnamaldehydes into lignin. Another change downregulation or overexpression ferulate 5-hydroxylase (F5H), which lignins enriched guaiacyl syringyl units, respectively. Here, we combined these approaches...

There is considerable debate over the capacity of cell wall polymer lignin to incorporate unnatural monomer units. We have identified Tnt1 retrotransposon insertion mutants barrel medic ( Medicago truncatula ) that show reduced autofluorescence under UV microscopy and red coloration in interfascicular fibers. The phenotype caused by retrotransposons into a gene annotated as encoding cinnamyl alcohol dehydrogenase, here designated M. CAD1 . NMR analysis indicated derived almost exclusively...

Significance This study shows that metabolic engineering can be used to imbue pine tracheary elements with an ability synthesize sinapyl alcohol, a lignin monomer not normally for lignification in conifers such as pine. The dynamic nature of the process enables pines incorporate this monolignol, allowing them produce hardwood-like lignins are known facilitate refining processes biofuel production and chemical pulping. potential improve conifer-derived biomass through manipulations is...

Lignin, a ubiquitous phenylpropanoid polymer in vascular plant cell walls, is derived primarily from oxidative couplings of monolignols (p-hydroxycinnamyl alcohols). It was discovered recently that wide range grasses, including cereals, utilize member the flavonoids, tricin (3′,5′-dimethoxyflavone), as natural comonomer with for wall lignification. Previously, we established cytochrome P450 93G1 flavone synthase II (OsFNSII) indispensable biosynthesis soluble tricin-derived metabolites rice...

Lignin, a major component of the secondary cell wall, is important for plant growth and development. Moreover, lignin plays pivotal role in innate immunity. Lignin readily deposited upon pathogen infection functions as physical barrier that limits spread pathogens. In this study, we show an Arabidopsis MYB transcription factor MYB15 required activation biosynthesis genes such PAL, C4H, 4CL, HCT, C3'H, COMT, CAD, consequently formation during effector-triggered immune responses. Upon...

Lignin is an abundant phenylpropanoid polymer produced by the oxidative polymerization of p-hydroxycinnamyl alcohols (monolignols). Lignification, i.e., deposition lignin, a defining feature secondary cell wall formation in vascular plants, and provides important mechanism for their disease resistance; however, many aspects lignification process remain unclear partly because lack suitable imaging methods to monitor vivo. In this study, set monolignol analogs γ-linked fluorogenic...

Demethylation of guaiacyl-type synthetic lignin (GDHP) with three different reagents, 1-dodecanethiol (DSH), hydroiodic acid (HI), and iodocyclohexane (ICH), was investigated as a basic study for functionalization. did not proceed efficiently in the reaction DSH, although cleavage side chains nucleophilic substitution by DSH occurred. proceeded reactions HI ICH, significant chains. Furthermore, recondensation also occurred ICH. As result, ICH found to be most effective demethylation reagent...

Summary p ‐Coumaroyl ester 3‐hydroxylase (C3′H) is a key enzyme involved in the biosynthesis of lignin, phenylpropanoid polymer that major constituent secondary cell walls vascular plants. Although crucial role C3′H lignification and its manipulation to upgrade lignocellulose have been investigated eudicots, limited information available monocotyledonous grass species, despite their potential as biomass feedstocks. Here we address pronounced impacts C3 ′ H deficiency on structure properties...

Striga species are parasitic weeds that seriously constrain the productivity of food staples, including cereals and legumes, in Sub-Saharan Africa Asia. In eastern central Africa, spp. infest as much 40 million hectares smallholder farmland causing total crop failure during severe infestation. As molecular mechanisms underlying resistance yet to be elucidated, we undertook a comparative metabolome study using Striga-resistant rice (Oryza sativa) cultivar 'Nipponbare' susceptible...

Summary Parasitic plants in the family Orobanchaceae are destructive weeds of agriculture worldwide. The haustorium, an essential parasitic organ used by these to penetrate host tissues, is induced host‐derived phenolic compounds called haustorium‐inducing factors ( HIF s). origin s remains unknown, although structures lignin monomers resemble that s. Lignin a natural phenylpropanoid polymer, commonly found secondary cell walls vascular plants. We therefore investigated possibility derived...

Lignin is a major component of cell wall biomass and decisively affects utilisation. Engineering lignin biosynthesis extensively studied, while modification often causes growth defects. We developed strategy for cell-type-specific to achieve improvements in property without penalty. targeted lignin-related transcription factor, LTF1, biosynthesis. LTF1 can be engineered nonphosphorylation form which introduced into Populus under the control either vessel-specific or fibre-specific promoter....

Lignin is a major lock for lignocellulose valorization in biorefineries, prompting need to find new ligninolytic systems. Termites are efficient degraders, and large part of this ability comes from its anaerobic gut microbiome. However, the potential termite microbiomes degrade lignin under conditions has yet be elucidated. By applying wet chemistry, multidimensional NMR spectroscopy, quantitative 13C-IS py-GC-MS, we determined chemical structural characteristics wheat straw digested by...

Abstract Lignin is a complex phenylpropanoid polymer deposited in the secondary cell walls of vascular plants. Unlike most gymnosperm and eudicot lignins that are generated via polymerization monolignols, grass additionally incorporate flavonoid tricin as natural lignin monomer. The biosynthesis functions tricin-integrated (tricin-lignin) its effects on utility biomass remain largely unknown. We herein report comparative analysis rice (Oryza sativa) mutants deficient early biosynthetic genes...

The evolutionary plant-pathogen arms race has equipped plants with the immune system that can defend against pathogens. Pattern-triggered immunity and effector-triggered are two major branches of innate share responses, including oxidative bursts, transcriptional reprogramming, cell wall modifications such as lignin deposition. In a previous study, we reported rapidly accumulates in pathogen-infected Arabidopsis leaves acts mechanical barrier, spatially restricting pathogens death. Lignin...