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Journal ArticleDOI

Inducibly-formed isoflavonoids from leaves of soybean

01 Jan 1981-Phytochemistry (Pergamon)-Vol. 20, Iss: 4, pp 795-798
TL;DR: Isoformononetin, glyceollins I, II and 2-isopentenyl-3,6a,9-trihydroxypterocarpan (glyceocarpin) accumulated in soybean leaves after treatment with aqueous sodium iodoacetate or a cell suspension of the bacterium, Pseudomonas pisi.
About: This article is published in Phytochemistry.The article was published on 1981-01-01. It has received 70 citations till now. The article focuses on the topics: Glycine.
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Book
05 Dec 1995
TL;DR: Phenolics in Food and Nutraceuticals as mentioned in this paper is the first single-source compendium of essential information concerning food phenolics, which reports the classification and nomenclature of phenolics and their occurrence in food and nutraceuticals.
Abstract: Phenolics in Food and Nutraceuticals is the first single-source compendium of essential information concerning food phenolics. This unique book reports the classification and nomenclature of phenolics, their occurrence in food and nutraceuticals, chemistry and applications, and nutritional and health effects. In addition, it describes antioxidant activity of phenolics in food and nutraceuticals as well as methods for analysis and quantification. Each chapter concludes with an extensive bibliography for further reading. Food scientists, nutritionists, chemists, biochemists, and health professionals will find this book valuable.

1,252 citations

Journal ArticleDOI
TL;DR: It is demonstrated that the simple isoflavones daidzein and genistein, which occur in soybean root exudates, are highly effective chemoattractants for zoospores of Phytophthora sojae, an economically important pathogen of soybeans.

202 citations

Journal ArticleDOI
TL;DR: Roots ofsoybean (Glycine max cv) and Amsoy 71 were analysed for their contents of stress metabolites 4, 6 and 8 weeks after the plants had been inoculated with different vesicular-arbuscular (VA) endomycorrhizal fungi (Glomus mosseae or Glomus fasciculatus or a mixture of the two).
Abstract: Roots ofsoybean (Glycine max cv. Amsoy 71) were analysed for their contents of stress metabolites 4, 6 and 8 weeks after the plants had been inoculated with different vesicular-arbuscular (VA) endomycorrhizal fungi (Glomus mosseae or Glomus fasciculatus or a mixture of the two) or 2 and 4 days after treatment with CuSO4 (10−3 m). All these treatments increased the concentrations of three isoflavonoids: glyceollin I, coumestrol and diadzein. The concentration of the phytoalexin glyceollin was greater in mycorrhizal infected roots than in non-mycorrhizal roots, but the amounts present were always low (< 1·0 μg g−1 fresh weight). The amounts of coumestrol and daidzein found in mycorrhizal roots varied between 7 and 34 μg g−1 fresh weight. The results are discussed in relation to the reported reduction of soil-borne disease caused by VA endomycorrhizal infection of plants.

186 citations

Journal ArticleDOI
TL;DR: It is concluded that the response of soybean cotyledons to Dpm elicitor involves NO formation via a constitutive NOS-like enzyme that triggers the biosynthesis of antimicrobial flavonoids.
Abstract: Phytoalexin biosynthesis is part of the defense mechanism of soybean (Glycine max) plants against attack by the fungus Diaporthe phaseolorum f. sp. meridionalis (Dpm), the causal agent of stem canker disease. The treatment of soybean cotyledons with Dpm elicitor or with sodium nitroprusside (SNP), a nitric oxide (NO) donor, resulted in a high accumulation of phytoalexins. This response did not occur when SNP was replaced by ferricyanide, a structural analog of SNP devoid of the NO moiety. Phytoalexin accumulation induced by the fungal elicitor, but not by SNP, was prevented when cotyledons were pretreated with NO synthase (NOS) inhibitors. The Dpm elicitor also induced NOS activity in soybean tissues proximal to the site of inoculation. The induced NOS activity was Ca(2+)- and NADPH-dependent and was sensitive to the NOS inhibitors N(G)-nitro-L-arginine methyl ester, aminoguanidine, and L-N(6)-(iminoethyl) lysine. NOS activity was not observed in SNP-elicited tissues. An antibody to brain NOS labeled a 166-kD protein in elicited and nonelicited cotyledons. Isoflavones (daidzein and genistein), pterocarpans (glyceollins), and flavones (apigenin and luteolin) were identified after exposure to the elicitor or SNP, although the accumulation of glyceollins and apigenin was limited in SNP-elicited compared with fungal-elicited cotyledons. NOS activity preceded the accumulation of these flavonoids in tissues treated with the Dpm elicitor. The accumulation of these metabolites was faster in SNP-elicited than in fungal-elicited cotyledons. We conclude that the response of soybean cotyledons to Dpm elicitor involves NO formation via a constitutive NOS-like enzyme that triggers the biosynthesis of antimicrobial flavonoids.

153 citations


Cites background from "Inducibly-formed isoflavonoids from..."

  • ...This color in soybean tissues results from the accumulation of certain glyceollin precursors following exposure to various biotic and abiotic factors (Ingham et al., 1981; Zähringer et al., 1981), and its intensity is proportional to the phytoalexin content (Ayers et al., 1976b)....

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  • ...Glyceollin precursors that have a red coloration include glycinol and the isoprenylated compounds glyceolidin I and II (Ingham et al., 1981; Zähringer et al., 1981)....

    [...]

Journal ArticleDOI
TL;DR: A minimal-wound protocol is employed to clearly separate and characterize the specific contributions of light, wounding, and a wall glucan elicitor preparation from Phytophthora sojae to the regulation of phenylpropanoid defense responses in soybean cotyledon tissues.
Abstract: The spatial and temporal deployment of plant defense responses involves a complex interplay of signal events, often resulting in superimposition of signaling processes. We have employed a minimal-wound protocol to clearly separate and characterize the specific contributions of light, wounding, and a wall glucan elicitor preparation (PWG) from Phytophthora sojae (Kauf. and Gerde.) to the regulation of phenylpropanoid defense responses in soybean (Glycine max L. [Merr.]) cotyledon tissues. The assay also allowed us to clearly reconstitute responses to combinations of these primary signals and to examine the effects of other pathogenesis-related molecules on the responses in a defined manner. Light specifically triggers accumulation of malonylglucosyl conjugates of the 5-hydroxy-isoflavone, genistein, which is normally found in epidermal cells. PWG selectively induces accumulation of conjugates of the 5-deoxy-isoflavone daidzein, the first committed precursor of the phytoalexin glyceollin. Wounding initiates phenolic polymer deposition, a process greatly potentiated by PWG and light. Whereas glutathione selectively enhances light induction of genistein conjugates, methyl jasmonate enhances both light and PWG-induced isoflavone conjugate accumulations. Wound exudate fully activates the cell's capacity (competency) for the phenolic polymer and glyceollin responses to PWG, whereas glutathione partially restores competency, favoring coumestrol and phenolic polymer responses to PWG. Abscisic acid inhibits all induced phenylpropanoid responses.

145 citations

References
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Journal ArticleDOI
24 Mar 1978-Nature
TL;DR: Levels of glyceollin, a phytoalexin produced by soybean [Glycine max (L.) Merr.] hypocotyls in response to infection with the fungal pathogen Phytophthora megasperma var.
Abstract: PHYTOALEXINS are inducibly formed higher plant metabolites that are antibiotic to certain potential plant pathogens1. At least 75 plant species representing 20 families have been shown to accumulate phytoalexins in response to infection1–3. Phytoalexins also accumulate in plants in response to various agents termed elicitors1, including substances of pathogen origin (biotic elicitors) and abiotic elicitors such as heavy metal salts and detergents1–3. Elicitors may be useful for investigation of the molecular basis of phytoalexin production or disease resistance expression1. However, the mechanisms by which such diverse elicitor molecules induce phytoalexin accumulation in plants are unknown. I have found4 that levels of glyceollin, a phytoalexin produced by soybean [Glycine max (L.) Merr.] hypocotyls in response to infection with the fungal pathogen Phytophthora megasperma var. sojae A. A. Hildb., are regulated by relative rates of induced biosynthesis and constitutive degrading activity. I report here the effects of various biotic and abiotic elicitors on biosynthesis and degradation of glyceollin in soybean tissues.

96 citations

Journal ArticleDOI
TL;DR: Data indicated that the HR of soybean leaves to P. glycinea was not related to permeability alteration but instead to the inducible accumulation of isoflavanoids, which was chronologically related to the restriction of bacterial multiplication.
Abstract: The hypersensitive reaction (HR) of soybean leaves to incompatible races of Pseudomonas glycinea was typified by rapid accumulation of the isoflavanoid compounds hydroxyphaseollin, coumestrol, daidzein and sojagol. The same compounds accumulated in response to inoculation with the non-pathogen P. lachrymans . In contrast, compatible races of P. glycinea led to delayed appearance of the isoflavanoids and the levels attained were 10% or less of those in resistant leaves. Accumulation of the isoflavanoids in resistant leaves was chronologically related to the restriction of bacterial multiplication. Cyclic-3′,5′-adenosine monophosphate at pH8 caused both the HR and isoflavanoid accumulation when supplied to leaves with normally compatible P. glycinea races. Hydroxyphaseollin possessed antibacterial properties in vitro at 25 to 100 parts/10 6 , concentrations that are less than 10% of those occurring in resistant soybean leaves. Coumestrol also inhibited colony development by P. glycinea in bioassays. Pronounced electrolyte loss did not occur in incompatible P. glycinea -soybean combinations, but was observed at the time of symptom appearance in leaves inoculated with compatible races. The data indicated that the HR of soybean leaves to P. glycinea was not related to permeability alteration but instead to the inducible accumulation of isoflavanoids.

94 citations

Journal ArticleDOI
TL;DR: The induced antifungal compound in soybean is shown to have been previously incorrectly identified by other workers as 6a-hydroxyphaseollin and a new structure is proposed.

74 citations

Journal ArticleDOI
TL;DR: Cristacarpin, a new phytoalexin from Erythrina crista-galli is assigned the structure (−)-3,6a-dihydroxy-9-methoxy-10-γ,γ-dimethylallyl- cis -pterocarpan, and chirality assignments are made for a number of previously unassigned compounds.

63 citations