RESUMO
Phenolic compounds with antioxidant properties have risen in interest due to their benefits for human health. Fragaria chiloensis is a native wild berry species from Chile that develops a white/pink receptacle and white flesh at the ripe stage. Changes in color parameters, anthocyanins, secondary metabolites (phenolics, flavonoids), and total antioxidant capacity were followed during the development and ripening of F. chiloensis fruit. The increment in color 'a' index takes place in parallel with anthocyanins rise and the reduction in phenolics, flavonoids, and antioxidant capacity. Good correlations were determined between color development, anthocyanins, and the expression of key phenylpropanoid/flavonoid and anthocyanin pathway genes. To investigate the role of ABA on color development, detached immature fruit (C2 stage) were treated with exogenous ABA and stored at 20 °C. Fruit color development was accelerated by ABA treatment compared to non-treated fruit, and consistent with that, the increment in the accumulation of anthocyanins and transcripts of phenylpropanoid/flavonoid, and anthocyanin pathways genes such as FcPAL, FcCHS, and FcANS were observed. This suggests that ABA promotes transcriptional changes that lead to the color formation on this non-climacteric fruit.
Assuntos
Antocianinas , Fragaria , Antocianinas/metabolismo , Antioxidantes/metabolismo , Flavonoides/metabolismo , Fragaria/metabolismo , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Humanos , Fenóis/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMO
Transcription factors are important regulators of gene expression. They can orchestrate the activation or repression of hundreds or thousands of genes and control diverse processes in a coordinated way. This work explores the effect of a master regulator of plant development, BOLITA (BOL), in plant metabolism, with a special focus on specialized metabolism. For this, we used an Arabidopsis thaliana line in which the transcription factor activity can be induced. Fingerprinting metabolomic analyses of whole plantlets were performed at different times after induction. After 96 h, all induced replicas clustered as a single group, in contrast with all controls which did not cluster. Metabolomic analyses of shoot and root tissues enabled the putative identification of differentially accumulated metabolites in each tissue. Finally, the analysis of global gene expression in induced vs. non-induced root samples, together with enrichment analyses, allowed the identification of enriched metabolic pathways among the differentially expressed genes and accumulated metabolites after the induction. We concluded that the induction of BOL activity can modify the Arabidopsis metabolome. Future work should investigate whether its action is direct or indirect, and the implications of the metabolic changes for development regulation and bioprospection.
Assuntos
Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Metaboloma , Fatores de Transcrição/metabolismo , Arabidopsis , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica no Desenvolvimento , Fatores de Transcrição/genética , TranscriptomaRESUMO
Lignin is the main component of secondary cell walls and is essential for plant development and defense. However, lignin is recognized as a major recalcitrant factor for efficiency of industrial biomass processing. Genes involved in general phenylpropanoid and monolignol-specific metabolism in sugarcane have been previously analyzed at the transcriptomic level. Nevertheless, the number of genes identified in this species is still very low. The recently released sugarcane genome sequence has allowed the genome-wide characterization of the 11 gene families involved in the monolignol biosynthesis branch of the phenylpropanoid pathway. After an exhaustive analysis of sugarcane genomes, 438 haplotypes derived from 175 candidate genes from Saccharum spontaneum and 144 from Saccharum hybrid R570 were identified as associated with this biosynthetic route. The phylogenetic analyses, combined with the search for protein conserved residues involved in the catalytic activity of the encoded enzymes, were employed to identify the family members potentially involved in developmental lignification. Accordingly, 15 candidates were identified as bona fide lignin biosynthesis genes: PTAL1, PAL2, C4H4, 4CL1, HCT1, HCT2, C3'H1, C3'H2, CCoAOMT1, COMT1, F5H1, CCR1, CCR2, CAD2, and CAD7. For this core set of lignin biosynthetic genes, we searched for the chromosomal location, the gene expression pattern, the promoter cis-acting elements, and microRNA targets. Altogether, our results present a comprehensive characterization of sugarcane general phenylpropanoid and monolignol-specific genes, providing the basis for further functional studies focusing on lignin biosynthesis manipulation and biotechnological strategies to improve sugarcane biomass utilization.
Assuntos
Genes de Plantas , Lignina/biossíntese , Saccharum/genética , Haplótipos , Lignina/genética , Fenilpropionatos/metabolismo , Filogenia , Polimorfismo Genético , Saccharum/classificação , Saccharum/metabolismoRESUMO
Caffeate 3-O-methyltransferase (COMT) catalyzes the methylation of the 3-hydroxyl group of caffeate to produce ferulate, an important precursor of the lignin biosynthesis. As a crucial drawback for biofuel production, lignin limits the enzymatic hydrolysis of polysaccharides to result in fermentable sugars. We hypothesized that a controlled inhibition of maize COMT can be an efficient approach to reduce ferulate and lignin, thus improving the saccharification process. First, we applied in silico techniques to prospect potential inhibitors of ZmaysCOMT, and the nitrocatechol entacapone was selected. Second, in vitro assays confirmed the inhibitory effect of entacapone on maize COMT. Finally, in vivo experiments revealed that entacapone reduced the contents of cell-wall-esterified hydroxycinnamates and increased saccharification of stems (18%) and leaves (70%), without negatively affecting maize growth and lignin biosynthesis. This non-genetically modified approach can be an alternative strategy to facilitate the enzymatic hydrolysis of biomass polysaccharides and increase saccharification for bioethanol production.
Assuntos
Catecóis , Lignina , Nitrilas , Polissacarídeos , Zea mays , Biocombustíveis , Biomassa , Inibidores de Catecol O-Metiltransferase/farmacologia , Catecóis/farmacologia , Parede Celular/efeitos dos fármacos , Nitrilas/farmacologia , Plantas Geneticamente Modificadas , Polissacarídeos/metabolismo , Zea mays/efeitos dos fármacosRESUMO
The phenylpropanoid pathway is an important route of secondary metabolism involved in the synthesis of different phenolic compounds such as phenylpropenes, anthocyanins, stilbenoids, flavonoids, and monolignols. The flux toward monolignol biosynthesis through the phenylpropanoid pathway is controlled by specific genes from at least ten families. Lignin polymer is one of the major components of the plant cell wall and is mainly responsible for recalcitrance to saccharification in ethanol production from lignocellulosic biomass. Here, we identified and characterized sugarcane candidate genes from the general phenylpropanoid and monolignol-specific metabolism through a search of the sugarcane EST databases, phylogenetic analysis, a search for conserved amino acid residues important for enzymatic function, and analysis of expression patterns during culm development in two lignin-contrasting genotypes. Of these genes, 15 were cloned and, when available, their loci were identified using the recently released sugarcane genomes from Saccharum hybrid R570 and Saccharum spontaneum cultivars. Our analysis points out that ShPAL1, ShPAL2, ShC4H4, Sh4CL1, ShHCT1, ShC3H1, ShC3H2, ShCCoAOMT1, ShCOMT1, ShF5H1, ShCCR1, ShCAD2, and ShCAD7 are strong candidates to be bona fide lignin biosynthesis genes. Together, the results provide information about the candidate genes involved in monolignol biosynthesis in sugarcane and may provide useful information for further molecular genetic studies in sugarcane.
Assuntos
Vias Biossintéticas/genética , Lignina/biossíntese , Proteínas de Plantas/genética , Propanóis/metabolismo , Saccharum/genética , Saccharum/metabolismo , Regulação da Expressão Gênica de Plantas , Genótipo , Lignina/genética , Propanóis/química , Saccharum/classificação , Saccharum/crescimento & desenvolvimentoRESUMO
Biomimetically incorporated into the lignin structure, rosmarinic acid improves in vitro maize cell wall saccharification; however, no in planta studies have been performed. We hypothesized that rosmarinic acid, itself, could inducer saccharification without disturbing plant growth. Its effects on growth, enzymes of the phenylpropanoid pathway, lignin, monomeric composition, and saccharification of maize were evaluated. In a short-term (24â¯h) exposure, rosmarinic acid caused deleterious effects on maize roots, inhibiting the first enzymes of the phenylpropanoid pathway, phenylalanine ammonia-lyase and tyrosine ammonia-lyase, altering lignin composition and slightly increasing saccharification. In a long-term (14â¯d) exposure, rosmarinic acid increased saccharification of maize stems by about 50% without any deleterious effects on plant growth, the phenylpropanoid pathway and lignin formation. This demonstrated that exogenous application of rosmarinic acid on maize plants improved saccharification, and represented an interesting approach in facilitating enzymatic hydrolysis of biomass polysaccharides and increasing bioethanol production.
Assuntos
Metabolismo dos Carboidratos/efeitos dos fármacos , Cinamatos/farmacologia , Depsídeos/farmacologia , Lignina/metabolismo , Zea mays/efeitos dos fármacos , Parede Celular , Relação Dose-Resposta a Droga , Redes e Vias Metabólicas/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo , Ácido RosmarínicoRESUMO
Caffeic acid (CA; 3,4-dihydroxycinnamic acid) is an aromatic compound obtained by the phenylpropanoid pathway. This natural product has antioxidant, antitumor, antiviral, and anti-inflammatory activities. It is also a precursor of CA phenethyl ester (CAPE), a compound with potential as an antidiabetic and liver-protective agent. CA can be found at low concentrations in plant tissues, and hence, its purification is difficult and expensive. Knowledge regarding the pathways, enzymes, and genes involved in CA biosynthesis has paved the way for enabling the design and construction of microbial strains with the capacity of synthesizing this metabolite. In this review, metabolic engineering strategies for the generation of Escherichia coli strains for the biotechnological production of CA are presented and discussed.
Assuntos
Ácidos Cafeicos/metabolismo , Escherichia coli/metabolismo , Engenharia Metabólica/métodos , Produtos Biológicos , Biotecnologia , Ácidos CumáricosRESUMO
In recent years, the use of biostimulants in sustainable agriculture has been growing. Biostimulants can be obtained from different organic materials and include humic substances (HS), complex organic materials, beneficial chemical elements, peptides and amino acids, inorganic salts, seaweed extracts, chitin and chitosan derivatives, antitranspirants, amino acids and other N-containing substances. The application of biostimulants to plants leads to higher content of nutrients in their tissue and positive metabolic changes. For these reasons, the development of new biostimulants has become a focus of scientific interest. Among their different functions, biostimulants influence plant growth and nitrogen metabolism, especially because of their content in hormones and other signalling molecules. A significant increase in root hair length and density is often observed in plants treated with biostimulants, suggesting that these substances induce a nutrient acquisition response that favors nutrient uptake in plants via an increase in the absorptive surface area. Furthermore, biostimulants positively influence the activity and gene expression of enzymes functioning in the primary and secondary plant metabolism. This article reviews the current literature on two main classes of biostimulants: humic substances and protein-based biostimulants. The characteristic of these biostimulants and their effects on plants are thoroughly described.
Assuntos
Fenômenos Fisiológicos Vegetais , Metabolismo Energético , Proteína Hidrolisada Vegetal , Substâncias Húmicas , Substâncias Húmicas/análiseRESUMO
In recent years, the use of biostimulants in sustainable agriculture has been growing. Biostimulants can be obtained from different organic materials and include humic substances (HS), complex organic materials, beneficial chemical elements, peptides and amino acids, inorganic salts, seaweed extracts, chitin and chitosan derivatives, antitranspirants, amino acids and other N-containing substances. The application of biostimulants to plants leads to higher content of nutrients in their tissue and positive metabolic changes. For these reasons, the development of new biostimulants has become a focus of scientific interest. Among their different functions, biostimulants influence plant growth and nitrogen metabolism, especially because of their content in hormones and other signalling molecules. A significant increase in root hair length and density is often observed in plants treated with biostimulants, suggesting that these substances induce a nutrient acquisition response that favors nutrient uptake in plants via an increase in the absorptive surface area. Furthermore, biostimulants positively influence the activity and gene expression of enzymes functioning in the primary and secondary plant metabolism. This article reviews the current literature on two main classes of biostimulants: humic substances and protein-based biostimulants. The characteristic of these biostimulants and their effects on plants are thoroughly described.(AU)
Assuntos
Fenômenos Fisiológicos Vegetais , Proteína Hidrolisada Vegetal , Metabolismo Energético , Substâncias Húmicas/análise , Substâncias HúmicasRESUMO
In the near future, grasses must provide most of the biomass for the production of renewable fuels. However, grass cell walls are characterized by a large quantity of hydroxycinnamic acids such as ferulic and p-coumaric acids, which are thought to reduce the biomass saccharification. Ferulic acid (FA) binds to lignin, polysaccharides and structural proteins of grass cell walls cross-linking these components. A controlled reduction of FA level or of FA cross-linkages in plants of industrial interest can improve the production of cellulosic ethanol. Here, we review the biosynthesis and roles of FA in cell wall architecture and in grass biomass recalcitrance to enzyme hydrolysis.