Isoflavonoids

Dewick, Paul M.

doi:10.1007/978-1-4899-2913-6_5

Cited by 36 publications

(14 citation statements)

References 273 publications

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“…It was therefore concluded that CII was a direct derivative of CI and subsequent structural elucidation therefore focused on CII. In addition to the ion peak at 298 m/z, the MS (EI) spectrum of CII showed the typical Retro-Diels-Alder fragmentation pattern of isoflavones (7,21 (4) as the aglycone, although our data do not completely rule out the possibility that the methoxy group could be on the 7 rather than the 6 position of the A-ring. Afrormosin is, however, found in a wide range of legume species (7).…”

Section: Structural Elucidation Of Isoflavonoid Conjugatescontrasting

confidence: 66%

“…Leguminous plants accumulate a wide range of phenolic secondary compounds, including isoflavonoid conjugates, and in many cases the routes of their biosynthesis have been elucidated (6,7,13). However, no detailed quantitative analyses are available on the accumulation of many of these compounds in specific parts of the plant or under stress conditions, such as occur following infection or treatment with microbial elicitors.…”

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confidence: 99%

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Stress Responses in Alfalfa (Medicago sativa L.)

Keßmann

Edwards²,

Geno³

et al. 1990

Plant Physiol.

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The isoflavonoid conjugates medicarpin-3-0-glucoside-6"-Omalonate (MGM), afrormosin-7-O-glucoside (AG), and afrormosin-7-O-glucoside-6"-O-malonate (AGM) were isolated and characterized from cell suspension cultures of alfalfa (Medicago sativa L.), where they were the major constitutive secondary metabolites. They were also found in alfalfa roots but not in other parts of the plant. The phytoalexin medicarpin accumulated rapidly in suspension cultured cells treated with elicitor from Colletotrichum lindemuthianum, and this was subsequently accompanied by an increase in the levels of MGM. In contrast, net accumulation of afrormosin conjugates was not affected by elicitor treatment.Labeling studies with [14CJphenylalanine indicated that afrormosin conjugates were the major de novo synthesized isoflavonoid products in unelicited cells. During elicitation, [14C]phenylalanine was incorporated predominantly into medicarpin, although a significant proportion of the newly synthesized medicarpin was also conjugated. Treatment of 14C-labeled, elicited cells with L-a-aminooxy-,#-phenylpropionic acid, a potent inhibitor of PAL activity in vivo, resulted in the initial appearance of labeled medicarpin of very low specific activity, suggesting that the phytoalexin could be released from a preformed conjugate under these conditions. Our data draw attention to the involvement of isoflavone hydroxylases during the constitutive and elicitor-induced accumulation of isoflavonoids and their conjugates in alfalfa cell cultures.

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Section: Structural Elucidation Of Isoflavonoid Conjugatescontrasting

confidence: 66%

mentioning

confidence: 99%

Stress Responses in Alfalfa (Medicago sativa L.)

Keßmann

Edwards²,

Geno³

et al. 1990

Plant Physiol.

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“…1), a pterocarpanoid phytoalexin synthesized by pea (Pisum sativum L), was the first phytoalexin whose chemical structure was identified (Cruickshank and Perrin, 1960;Perrin and Bottomley, 1962). Significant progress towards elucidating the pathway for its biosynthesis has been made through biochemical studies in pea and related legumes (Dewick, 1988(Dewick, ,1994Dixon, 1999). The basic pterocarpan carbon skeleton contains four rings ABCD as shown for (+)-pisatin 8 in Fig.…”

Section: Introductionmentioning

confidence: 97%

“…1), the garden pea is somewhat unusual in that it synthesizes a (+)-pterocarpan, (+)-pisatin 8 ( Fig. 1) (Banks and Dewick, 1982b;Dewick, 1988).…”

Section: Introductionmentioning

confidence: 98%

Inactivation of pea genes by RNAi supports the involvement of two similar O-methyltransferases in the biosynthesis of (+)-pisatin and of chiral intermediates with a configuration opposite that found in (+)-pisatin

Kaimoyo

VanEtten

2008

Phytochemistry

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“…Phytoalexins are low molecular weight antimicrobial compounds synthesized by plants in response to attempted infection by fungal pathogens, exposure to elicitor macromolecules, or other biotic and abiotic stresses [14]- [17]. Isoflavonoid phytoalexins are characteristic of Leguminosae and are very rarely found in other plant families [18]. The pterocarpan medicarpin is the major phytoalexin in the alfalfa forage legume.…”

Section: Introductionmentioning

confidence: 99%

Gene Expression Modulation of Two Biosynthesis Pathways via Signal Transduction in <i>Cochliobolus heterostrophus</i>

Degani

2014

ABB

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G-protein-linked pathways have evolved to allow responses to extracellular agonists (hormones, neurotransmitters, odors, chemoattractants, light and nutrients) in eukaryotic cells, ranging from simpler systems, including yeasts, filamentous fungi and slime molds, to more complex organisms, such as mammals. Although the role of G-protein and mitogen-activated protein kinase (MAPK) in filamentous fungi has been studied for over a decade, downstream elements are less known, and the study of target genes has evolved mainly in recent years. Here, we examined the involvement of G-protein subunits and MAPK in controlling the expression of two distinct target genes. These genes were selected from an array database according to their unique expression profile and the role of closely related genes found in other Ascomycetes. One of these genes is BPH, which encodes the enzyme responsible for cytochrome P450-dependent benzoate hydroxylation in microsomes. The other gene is CIPA, which encodes isoflavone reductase (IfR), an enzyme involved in the synthesis of phytoalexin, which catalyzes an intermediate step in pisatin biosynthesis. The expression profile of these two genes was determined in a series of signaling deficiency mutants that were grown on different media using a DNA microarray. Comparison of the expression profile in the two wild type strains and mutants deficient in the G-protein α or β subunits or in MAPK, revealed a unique control mechanism for the BPH and CIPA genes. The two genes are highly expressed during the infection of the host plant leaves and may associate with the fungal response to the host. Signaling via G-protein or MAPK was shown to be related to cascades that altered the expression of these genes in response to the growth condition. This work demonstrates that signal transduction pathways are controlling genes that, although sharing an environmental dependent response, participate in distinct biosynthesis pathways. Moreover, the transcriptional profile may point to distinct and shared roles of the signaling components.O. Degani 341

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Isoflavonoids

Cited by 36 publications

References 273 publications

Stress Responses in Alfalfa (Medicago sativa L.)

Stress Responses in Alfalfa (Medicago sativa L.)

Inactivation of pea genes by RNAi supports the involvement of two similar O-methyltransferases in the biosynthesis of (+)-pisatin and of chiral intermediates with a configuration opposite that found in (+)-pisatin

Gene Expression Modulation of Two Biosynthesis Pathways via Signal Transduction in <i>Cochliobolus heterostrophus</i>

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Isoflavonoids

Cited by 36 publications

References 273 publications

Stress Responses in Alfalfa (Medicago sativa L.)

Stress Responses in Alfalfa (Medicago sativa L.)

Inactivation of pea genes by RNAi supports the involvement of two similar O-methyltransferases in the biosynthesis of (+)-pisatin and of chiral intermediates with a configuration opposite that found in (+)-pisatin

Gene Expression Modulation of Two Biosynthesis Pathways via Signal Transduction in &lt;i&gt;Cochliobolus heterostrophus&lt;/i&gt;

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Gene Expression Modulation of Two Biosynthesis Pathways via Signal Transduction in <i>Cochliobolus heterostrophus</i>