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...

Flavones are ubiquitously accumulated in land plants, but their biosynthesis monocots remained largely elusive until recent years. Recently, we demonstrated that the rice (Oryza sativa) cytochrome P450 enzymes CYP93G1 and CYP93G2 channel flavanones en route to flavone O-linked conjugates C-glycosides, respectively. In tricin, 3′,5′-dimethoxyflavone nucleus is formed before conjugations. Previously, flavonoid 3′,5′-hydroxylases belonging CYP75A subfamily were believed generate tricetin from...

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...

Flavones are a major class of flavonoids with wide range physiological functions in plants. They constitutively accumulated as C-glycosides and O-linked conjugates vegetative tissues grasses. It has long been presumed that the two structural modifications flavones occur through independent metabolic routes. Previously, we reported cytochrome P450 93G2 (CYP93G2) flavanone 2-hydroxylase (F2H) provides 2-hydroxyflavanones for C-glycosylation rice (Oryza sativa). Flavone subsequently formed by...

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....

Abstract Flavonoids are essential for male fertility in some but not all plant species. In rice (Oryza sativa), the chalcone synthase mutant oschs1 produces flavonoid-depleted pollen and is sterile. The grains viable with normal structure, they display reduced germination rate pollen-tube length. Analysis of oschs1/+ heterozygous lines shows that flavonoid deposition a paternal effect independent haploid genotypes (OsCHS1 or oschs1). To understand which classes flavonoids involved fertility,...

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...

Abstract Lignin is a phenylpropanoid polymer produced in the secondary cell walls of vascular plants. Although most eudicot and gymnosperm species generate lignins solely via polymerization p -hydroxycinnamyl alcohols (monolignols), grasses additionally use flavone, tricin, as natural lignin monomer to tricin-incorporated polymers walls. We previously found that disruption rice 5-HYDROXYCONIFERALDEHYDE O -METHYLTRANSFERASE ( OsCAldOMT1 ) reduced extractable tricin-type metabolites vegetative...

Flavonoids are ubiquitous in terrestrial plants with important physiological functions. The planta flavonoid profile depends on the activities of different biosynthesis enzymes (Figure 1a). Flavanone 3-hydroxylase (F3H) is a key enzyme channelling carbon flow towards production 3-hydroxylated flavonoids, including flavonols and anthocyanidins. In Poaceae, F3H-encoding genes generally inactive vegetative tissues which accumulate flavone derivatives as predominant metabolites. Meanwhile,...

The woody stems of coniferous gymnosperms produce specialised compression wood to adjust the stem growth orientation in response gravitropic stimulation. During this process, tracheids develop a compression-wood-specific S2 L cell wall layer with lignins highly enriched p-hydroxyphenyl (H)-type units derived from H-type monolignol, whereas produced walls normal are exclusively composed guaiacyl (G)-type G-type monolignol trace amount units. We show that laccases, class lignin polymerisation...

In rice (Oryza sativa), OsF2H and OsFNSII direct flavanones to independent pathways that form soluble flavone C-glycosides tricin-type metabolites (both lignin-bound), respectively. Production of tricin requires CYP75B4 as a chrysoeriol 5'-hydroxylase. Meanwhile, the close homologue CYP75B3 is canonical flavonoid 3'-hydroxylase (F3'H). However, their precise roles in biosynthesis tricin-lignins cell walls remain unknown. We examined expression vegetative tissues, analyzed extractable...

Summary Tricin (3′,5′‐dimethoxylated flavone) is a predominant flavonoid amongst monocots but occurs only in isolated and unrelated dicot lineages. Although tricin biosynthesis has been intensively studied monocots, it remained largely elusive tricin‐accumulating dicots. We investigated subgroup of cytochrome P450 (CYP) 75B subfamily B‐ring hydroxylases (FBHs) from two legumes, Medicago truncatula alfalfa ( sativa ), by phylogenetic, molecular, biochemical mutant analyses. Five CYP75B FBHs...

In the present work, lignin-like fractions were isolated from several ancestral plants -including moss (Hypnum cupressiforme and Polytrichum commune), lycophyte (Selaginella kraussiana), horsetail (Equisetum palustre), fern (Nephrolepis cordifolia Pteridium aquilinum), cycad (Cycas revoluta), gnetophyte (Ephedra fragilis) species- structurally characterized by pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy. Py-GC/MS...

The 4-coumarate:coenzyme A ligase (4CL) is a key enzyme that contributes to channeling metabolic flux in the cinnamate/monolignol pathway, leading production of monolignols, p-hydroxycinnamates, and flavonoid tricin, major building blocks lignin polymer grass cell walls. Vascular plants often contain multiple 4CL genes; however, contribution each isoform biosynthesis remains unclear, especially grasses. In this study, we characterized functions two rice (Oryza sativa L.) isoforms (Os4CL3...

Alternative splicing (AS) regulates gene expression and increases proteomic diversity for the fine tuning of stress responses in plants, but exact mechanism through which AS functions plant is not thoroughly understood. Here, we investigated how poplar (Populus trichocarpa), a popular bioremediation, response to lead (Pb) stress. Using proteogenomic analysis, determine that Pb induced alterations patterns are characterized by an increased use nonconventional splice sites higher abundance...

A sorghum pathogen-inducible gene predicted to encode a simple extracellular leucine-rich repeat (LRR) protein SbLRR2 was previously isolated. LRR the only domain identified in and its homologous sequences. Phylogenetic analysis revealed that they are distinct from proteins reported previously. Agrobacterium-mediated transient expression tobacco leaf cells demonstrated SbLRR2-EYFP (enhanced yellow fluorescent protein) fusion targeted space. Transgenic of role enhancing lead [Pb(II)]...

Abstract Grasses are abundant feedstocks that can supply lignocellulosic biomass for production of cell-wall-derived chemicals. In grass cell walls, lignin is acylated with p-coumarate. These p-coumarate decorations arise from the incorporation monolignol conjugates during lignification. A previous biochemical study identified a rice (Oryza sativa) BAHD acyltransferase (AT) p-coumaroyl-CoA:monolignol transferase (PMT) activity in vitro. this study, we determined enzyme, which name OsPMT1...