Incorporation Of Phenolic Compounds Research Articles

Soybean Stem Canker Caused by Diaporthe caulivora; Pathogen Diversity, Colonization Process, and Plant Defense Activation.

Soybean is an important crop in South America, and its production is limited by fungal diseases caused by species from the genus Diaporthe, including seed decay, pod and stem blight, and soybean stem canker (SSC). In this study, we focused on Diaporthe species isolated from soybean plants with SSC lesions in different parts of Uruguay. Diaporthe diversity was determined by sequencing the internal transcribed spacer (ITS) regions of ribosomal RNA and a partial region of the translation elongation factor 1-alpha gene (TEF1α). Phylogenetic analysis showed that the isolates belong to five defined groups of Diaporthe species, Diaporthe caulivora and Diaporthe longicolla being the most predominant species present in stem canker lesions. Due to the importance of D. caulivora as the causal agent of SSC in the region and other parts of the world, we further characterized the interaction of this pathogen with soybean. Based on genetic diversity of D. caulivora isolates evaluated with inter-sequence single repetition (ISSR), three different isolates were selected for pathogenicity assays. Differences in virulence were observed among the selected D. caulivora isolates on susceptible soybean plants. Further inspection of the infection and colonization process showed that D. caulivora hyphae are associated with trichomes in petioles, leaves, and stems, acting probably as physical adhesion sites of the hyphae. D. caulivora colonized the stem rapidly reaching the phloem and the xylem at 72 h post-inoculation (hpi), and after 96 hpi, the stem was heavily colonized. Infected soybean plants induce reinforcement of the cell walls, evidenced by incorporation of phenolic compounds. In addition, several defense genes were induced in D. caulivora–inoculated stems, including those encoding a pathogenesis-related protein-1 (PR-1), a PR-10, a β-1,3-glucanase, two chitinases, two lipoxygenases, a basic peroxidase, a defensin, a phenylalanine-ammonia lyase, and a chalcone synthase. This study provides new insights into the interaction of soybean with D. caulivora, an important pathogen causing SSC, and provides information on the activation of plant defense responses.

Activation of Shikimate, Phenylpropanoid, Oxylipins, and Auxin Pathways in Pectobacterium carotovorum Elicitors-Treated Moss.

Plants have developed complex defense mechanisms to cope with microbial pathogens. Pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) are perceived by pattern recognition receptors (PRRs), leading to the activation of defense. While substantial progress has been made in understanding the activation of plant defense by PAMPs and DAMPs recognition in tracheophytes, far less information exists on related processes in early divergent plants like mosses. The aim of this study was to identify genes that were induced in P. patens in response to elicitors of Pectobacterium carotovorum subsp. carotovorum, using a cDNA suppression subtractive hybridization (SSH) method. A total of 239 unigenes were identified, including genes involved in defense responses related to the shikimate, phenylpropanoid, and oxylipin pathways. The expression levels of selected genes related to these pathways were analyzed using quantitative RT-PCR, confirming their rapid induction by P.c. carotovorum derived elicitors. In addition, P. patens induced cell wall reinforcement after elicitor treatment by incorporation of phenolic compounds, callose deposition, and elevated expression of Dirigent-like encoding genes. Small molecule defense markers and phytohormones such as cinnamic acid, 12-oxo-phytodienoic acid, and auxin levels all increased in elicitor-treated moss tissues. In contrast, salicylic acid levels decreased while abscisic acid levels remained unchanged. P. patens reporter lines harboring an auxin-inducible promoter fused to β-glucuronidase revealed GUS activity in protonemal and gametophores tissues treated with elicitors of P.c. carotovorum, consistent with a localized activation of auxin signaling. These results indicate that P. patens activates the shikimate, phenylpropanoid, oxylipins, and auxin pathways upon treatment with P.c. carotovorum derived elicitors.

Effect of laboratory-scale decoction on the antioxidative activity of Zhenjiang Aromatic Vinegar: The contribution of melanoidins

Decoction, the characteristic heat-treatment procedure in Zhenjiang Aromatic Vinegar (ZAV) processing, was performed in laboratory to investigate its effect on the antioxidative activity (AA) of ZAV. Owing to the laboratory-scale decoction, DPPH radical scavenging activity, ORAC value and cellular antioxidant activity (CAA) of ZAV increased by 63, 24 and 54% of that of undecocted vinegar, respectively. Enzymatic assay and HPLC determination proved that phenolic content decreased after the decoction, while melanoidins, also with antioxidative activity and recently found in ZAV, were generated. Regardless of the fluctuation in AA of melanoidins during decoction, increased melanoidin content was responsible for the increase in AA of ZAV. At the end of the decoction, melanoidins accounted for 57.1 and 44.1% of the total AA of ZAV, according to DPPH and ORAC assays, respectively. Incorporation of phenolic compounds into melanoidins and degradation of melanoidins might both occur during decoction.

Physcomitrella patens Activates Defense Responses against the Pathogen Colletotrichum gloeosporioides.

The moss Physcomitrella patens is a suitable model plant to analyze the activation of defense mechanisms after pathogen assault. In this study, we show that Colletotrichum gloeosporioides isolated from symptomatic citrus fruit infects P. patens and cause disease symptoms evidenced by browning and maceration of tissues. After C. gloeosporioides infection, P. patens reinforces the cell wall by the incorporation of phenolic compounds and induces the expression of a Dirigent-protein-like encoding gene that could lead to the formation of lignin-like polymers. C. gloeosporioides-inoculated protonemal cells show cytoplasmic collapse, browning of chloroplasts and modifications of the cell wall. Chloroplasts relocate in cells of infected tissues toward the initially infected C. gloeosporioides cells. P. patens also induces the expression of the defense genes PAL and CHS after fungal colonization. P. patens reporter lines harboring the auxin-inducible promoter from soybean (GmGH3) fused to β-glucuronidase revealed an auxin response in protonemal tissues, cauloids and leaves of C. gloeosporioides-infected moss tissues, indicating the activation of auxin signaling. Thus, P. patens is an interesting plant to gain insight into defense mechanisms that have evolved in primitive land plants to cope with microbial pathogens.

Antioxidant and antimicrobial edible zein/chitosan composite films fabricated by incorporation of phenolic compounds and dicarboxylic acids

Edible films and coatings can not only function as barriers of water vapor, gases and volatile compounds but also serve as carriers of functional ingredients. Composite edible films fabricated with zein and chitosan as base materials and supplemented with phenolic compounds (ferulic acid or gallic acid) and dicarboxylic acids (adipic acid or succinic acid) were prepared. The composite films exerted better water vapor barrier and mechanical properties. While the recovery percentage of phenolic compounds from composite films was 71–84%, the recovery of dicarboxylic acids was 48–65%. The composite films also possessed antioxidant activities as shown by DPPH and ABTS free radical scavenging tests. The antimicrobial activity of composite film was demonstrated by using Staphylococcus aureus and Escherichia coli as test microorganisms.

Incorporation of phenolic compounds, rutin and epicatechin, into soy protein isolate films: Mechanical, barrier and cross-linking properties

Edible films prepared from soy protein isolate (SPI), with and without the phenolic compounds, rutin and epicatechin, as cross linking agents, were tested for their mechanical, optical and water vapour barrier properties. The addition of rutin significantly increased puncture strength (9.3N) over SPI alone (6.4N) whereas epicatechin had no effect. Tensile strengths of SPI films with rutin and epicatechin were similar (35.1MPa and 22.1MPa, respectively) and significantly stronger than films without added phenolics (9.3MPa). SPI films without phenolics showed the greatest flexibility, as measured by tensile elongation. The addition of epicatechin was found to increase water vapour permeability significantly to 2.3gmm/m2hkPa from 1.7gmm/m2hkPa for SPI alone whereas rutin decreased water vapour permeability to 1.2gmm/m2hkPa. Films without phenolics had lower opacity values than had those with phenolics. Findings indicate that rutin and epicatechin may be used as a natural means for improving specific properties of SPI films.

Nature of phenolic compounds in coffee melanoidins.

Phenolic compounds are incorporated into coffee melanoidins during roasting mainly in condensed form (42-62 mmol/100 g) and also in ester-linked form (1.1-1.6 mmol/100 g), with incorporation levels depending on the green coffee chlorogenic acid content. The phenolic compounds are incorporated in different coffee melanoidin populations, but mainly in those soluble in 75% ethanol (82%), a significant correlation between the amount of phenolic compounds and the amount of protein and color characteristics of the different melanoidin populations being observed. The incorporation of phenolic compounds into coffee melanoidins is a significant pathway of chlorogenic acid degradation during roasting, representing 23% of the chlorogenic acids lost. These account for the nearly 26% of the material not accounted for by polysaccharides and proteins present in coffee melanodins. The cleavage mechanism and the efficiency of alkaline fusion used to release condensed phenolics from coffee melanoidins suggest that the phenolic compounds can be linked to the polymeric material by aryl-ether, stilbene type, and/or biphenyl linkages.

Correction to Influence of Coffee Roasting on the Incorporation of Phenolic Compounds into Melanoidins and Their Relationship with Antioxidant Activity of the Brew

ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionNEXTORIGINAL ARTICLEThis notice is a correctionCorrection to Influence of Coffee Roasting on the Incorporation of Phenolic Compounds into Melanoidins and Their Relationship with Antioxidant Activity of the BrewDaniel Perrone, Adriana Farah*, and Carmen M. DonangeloCite this: J. Agric. Food Chem. 2012, 60, 45, 11447Publication Date (Web):November 1, 2012Publication History Published online1 November 2012Published inissue 14 November 2012https://doi.org/10.1021/jf304492vCopyright © 2012 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views496Altmetric-Citations3LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (116 KB) Get e-Alerts Get e-Alerts

Physcomitrella patens activates reinforcement of the cell wall, programmed cell death and accumulation of evolutionary conserved defence signals, such as salicylic acid and 12‐oxo‐phytodienoic acid, but not jasmonic acid, upon Botrytis cinerea infection

The moss Physcomitrella patens is an evolutionarily basal model system suitable for the analysis of plant defence responses activated after pathogen assault. Upon infection with the necrotroph Botrytis cinerea, several defence mechanisms are induced in P. patens, including the fortification of the plant cell wall by the incorporation of phenolic compounds and the induced expression of related genes. Botrytis cinerea infection also activates the accumulation of reactive oxygen species and cell death with hallmarks of programmed cell death in moss tissues. Salicylic acid (SA) levels also increase after fungal infection, and treatment with SA enhances transcript accumulation of the defence gene phenylalanine ammonia-lyase (PAL) in P. patens colonies. The expression levels of the genes involved in 12-oxo-phytodienoic acid (OPDA) synthesis, including lipoxygenase (LOX) and allene oxide synthase (AOS), increase in P. patens gametophytes after pathogen assault, together with a rise in free linolenic acid and OPDA concentrations. However, jasmonic acid (JA) could not be detected in healthy or infected tissues of this plant. Our results suggest that, although conserved defence signals, such as SA and OPDA, are synthesized and are probably involved in the defence response of P. patens against B. cinerea infection, JA production appears to be missing. Interestingly, P. patens responds to OPDA and methyl jasmonate by reducing moss colony growth and rhizoid length, suggesting that jasmonate perception is present in mosses. Thus, P. patens can provide clues with regard to the evolution of different defence pathways in plants, including signalling and perception of OPDA and jasmonates in nonflowering and flowering plants.

Influence of Coffee Roasting on the Incorporation of Phenolic Compounds into Melanoidins and Their Relationship with Antioxidant Activity of the Brew

In the present study, the influence of coffee roasting on free and melanoidin-bound phenolic compounds and their relationship with the brews' antioxidant activity (AA), evaluated by TRAP, TEAC, and TRAP, were investigated. Changes in the relative content of free chlorogenic acids (CGA), free lactones, and melanoidin-bound phenolic acids during roasting indicate that phenolic compounds were incorporated into melanoidins mainly at early stages of the process, being thereafter partly oxidized to dihydrocaffeic acid, and degraded. Although less than 1% of CGA in green coffee was incorporated into melanoidins during roasting, the relative content of melanoidin-bound phenolic acids increased significantly during this process, reaching up to 29% of total phenolic compounds in brews from dark roasted coffees. Regardless of the AA assay used and considering all roasting degrees, the overall contribution of CGA to the AA of the whole brews was higher than that of melanoidin-bound phenolic compounds. It was estimated that the latter compounds contributed to 25-47% of the AA, depending on the assay used.

Plant–pathogen interactions: a view from the evolutionary basement

Plant–pathogen interactions: a view from the evolutionary basement

Resistance to Botrytis cinerea in sitiens, an abscisic acid-deficient tomato mutant, involves timely production of hydrogen peroxide and cell wall modifications in the epidermis.

Plant defense mechanisms against necrotrophic pathogens, such as Botrytis cinerea, are considered to be complex and to differ from those that are effective against biotrophs. In the abscisic acid-deficient sitiens tomato (Solanum lycopersicum) mutant, which is highly resistant to B. cinerea, accumulation of hydrogen peroxide (H(2)O(2)) was earlier and stronger than in the susceptible wild type at the site of infection. In sitiens, H(2)O(2) accumulation was observed from 4 h postinoculation (hpi), specifically in the leaf epidermal cell walls, where it caused modification by protein cross-linking and incorporation of phenolic compounds. In wild-type tomato plants, H(2)O(2) started to accumulate 24 hpi in the mesophyll layer and was associated with spreading cell death. Transcript-profiling analysis using TOM1 microarrays revealed that defense-related transcript accumulation prior to infection was higher in sitiens than in wild type. Moreover, further elevation of sitiens defense gene expression was stronger than in wild type 8 hpi both in number of genes and in their expression levels and confirmed a role for cell wall modification in the resistant reaction. Although, in general, plant defense-related reactive oxygen species formation facilitates necrotrophic colonization, these data indicate that timely hyperinduction of H(2)O(2)-dependent defenses in the epidermal cell wall can effectively block early development of B. cinerea.