Summary The functions of phenylpropanoid compounds in plant defence range from preformed or inducible physical and chemical barriers against infection to signal molecules involved local systemic signalling for gene induction. Defensive are not restricted a particular class compound, but found the simple hydroxycinnamic acids monolignols through more complex flavonoids, isoflavonoids, stilbenes. enzymatic steps biosynthesis major classes now well established, many corresponding genes have...

Abstract Flavonoids are synthesized through an important metabolic pathway that leads to the production of diverse secondary metabolites, including anthocyanins, flavonols, flavones, and proanthocyanidins. Anthocyanins flavonols derived from Phe share common precursors, dihydroflavonols, which substrates for both flavonol synthase dihydroflavonol 4-reductase. In stems Arabidopsis thaliana, anthocyanins accumulate in acropetal manner, with highest level at junction between rosette stem. We...

The plant hormone salicylic acid (SA) plays critical roles in defense, stress responses, and senescence. Although SA biosynthesis is well understood, the pathways by which catabolized remain elusive. Here we report identification characterization of an 3-hydroxylase (S3H) involved catabolism during leaf S3H associated with senescence inducible thus a key part negative feedback regulation system levels enzyme converts (with K m 58.29 µM) to both 2,3-dihydroxybenzoic (2,3-DHBA) 2,5-DHBA vitro...

Abstract Phenylalanine ammonia-lyase (PAL) catalyzes the first rate-limiting step in phenylpropanoid pathway, which controls carbon flux to a variety of bioactive small-molecule aromatic compounds, and lignin, structural component cell wall. PAL is regulated at both transcriptional translational levels. Our knowledge about regulation relatively comprehensive, but our molecular basis posttranslational remains limited. Here, we demonstrate that Arabidopsis thaliana Kelch repeat F-box (KFB)...

The phytohormone salicylic acid (SA) plays essential roles in biotic and abiotic responses, plant development, leaf senescence. 2,5-Dihydroxybenzoic (2,5-DHBA or gentisic acid) is one of the most commonly occurring aromatic acids green plants assumed to be generated from SA, but enzymes involved its production remain obscure. DMR6 (Downy Mildew Resistant6; At5g24530) has been proven immunity Arabidopsis (Arabidopsis thaliana), biochemical properties are not well understood. Here, we report...

Cell suspensions of the model legume Medicago truncatula accumulated isoflavonoid phytoalexin medicarpin in response to yeast elicitor or methyl jasmonate (MJ), accompanied by decreased levels isoflavone glycosides MJ-treated cells. DNA microarray analysis revealed rapid, massive induction early (iso)flavonoid pathway gene transcripts elicitor, but not MJ, and differential two elicitors sets genes encoding transcription factors, ABC transporters, beta-glucosidases. In contrast, both induced...

Suberin, a polyester polymer in the cell wall of terrestrial plants, controls transport water and nutrients protects plant from pathogenic infections environmental stresses. Structurally, suberin consists aliphatic aromatic domains; p-hydroxycinnamates, such as ferulate, p-coumarate, and/or sinapate, are major phenolic constituents latter. By analyzing "wall-bound" phenolics mutant lines Arabidopsis deficient family acyl-CoA dependent acyltransferase (BAHD) genes, we discovered that...

Flavonoids represent a large family of specialized metabolites involved in plant growth, development, and adaptation. Chalcone synthase (CHS) catalyzes the first step flavonoid biosynthesis by directing carbon flux from general phenylpropanoid metabolism to pathway. Despite extensive characterization its function transcriptional regulation, molecular basis governing posttranslational modification is enigmatic. Here, we report discovery proteolytic regulator CHS, namely, KFBCHS, Kelch...

Abstract Pectin is a major component of the primary cell wall higher plants. Some galacturonyl residues in backbone pectinaceous polysaccharides are often O-acetylated at C-2 or C-3 position, and resulting acetylesters change dynamically during growth development The processes involve both enzymatic acetylation deacetylation. Through genomic sequence analysis, we identified pectin acetylesterase (PAE1) from black cottonwood (Populus trichocarpa). Recombinant Pt PAE1 exhibited preferential...

Suberin, a lipophilic polymer deposited in the outer integument of Arabidopsis (Arabidopsis thaliana) seed coat, represents an essential sealing component controlling water and solute movement protecting from pathogenic infection. Although many genes responsible for suberin synthesis are identified, regulatory components its biosynthesis have not been definitively determined. Here, we show that MYB107 transcription factor acts as positive regulator biosynthetic gene expression coat....

Summary Plants produce several hundreds of thousands secondary metabolites that are important for adaptation to various environmental conditions. Although different groups synthesized through unique biosynthetic pathways, plants must orchestrate their production simultaneously. Phenylpropanoids and glucosinolates two classes apparently independent pathways. Genetic evidence has revealed the accumulation glucosinolate intermediates limits phenylpropanoid in a Mediator Subunit 5 ( MED...

Cytochrome P450 system consists of monooxygenase and redox pattern(s). While the importance monooxygenases in plant metabolism is well documented, metabolic roles related components have been largely overlooked. Here, we show that distinct electron transfer chains are recruited phenylpropanoid-monolignol systems to support synthesis distribution different classes phenolics tissues. Arabidopsis cinnamate 4-hydroxylase adopts conventional NADPH-cytochrome oxidoreductase (CPR) chain for its...

In view of their perceived chemopreventive activities against hormone-dependent cancers, cardiovascular disease, and postmenopausal ailments, there is considerable interest in engineering plants to contain isoflavone phytoestrogens. However, attempts date have only resulted low levels accumulation non-legumes. Introducing soybean synthase (IFS) into Arabidopsis thaliana leads genistein glycosides. Leaves wild-type A. high similar conjugates the flavonols quercetin kaempferol, which could be...

Sorghum is considered to be one of the more allelopathic crop species, producing phytotoxins such as potent benzoquinone sorgoleone (2-hydroxy-5-methoxy-3-[(Z,Z)-8′,11′,14′-pentadecatriene]-p-benzoquinone) and its analogs. Sorgoleone likely accounts for much allelopathy spp., typically representing predominant constituent bicolor root exudates. Previous ongoing studies suggest that biosynthetic pathway this plant growth inhibitor occurs in hair cells, involving a polyketide synthase activity...

Although the practice of protein engineering is industrially fruitful in creating biocatalysts and therapeutic proteins, applications analogous techniques field plant metabolic are still their infancy. Lignins aromatic natural polymers derived from oxidative polymerization primarily three different hydroxycinnamyl alcohols, monolignols. Polymerization lignin starts with oxidation monolignols, followed by endwise cross-coupling (radicals of) a monolignol growing oligomer/polymer. The...

Abstract Producing cellulosic biofuels and bio-based chemicals from woody biomass is impeded by the presence of lignin polymer in plant cell wall. Manipulating monolignol biosynthetic pathway offers a promising approach to improved processability, but often impairs growth development. Here, we show that expressing an engineered 4- O -methyltransferase chemically modifies phenolic moiety monomeric precursors, thus preventing their incorporation into polymer, substantially alters hybrid...

Flavonoids ubiquitously distribute to the terrestrial plants and chalcone isomerase (CHI)-catalyzed intramolecular stereospecific cyclization of chalcones is a committed step in production flavonoids. However, so far bona fide CHIs are found only vascular plants, their origin evolution remains elusive. We conducted transcriptomic and/or genomic sequence search, subsequent phylogenetic analysis, detailed biochemical genetic characterization explore potential existence CHI proteins basal...