Phytoalexin
Mostrando 13-24 de 122 artigos, teses e dissertações.
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13. Potentiation of the Oxidative Burst and Isoflavonoid Phytoalexin Accumulation by Serine Protease Inhibitors1
Treatment of soybean (Glycine max L. cv Williams 82) cell-suspension cultures with Pseudomonas syringae pv glycinea (Psg) harboring an avirulence gene (avrA) or with yeast elicitor resulted in an oxidative burst characterized by the accumulation of H2O2. This burst, and the resultant induction of glutathione S-transferase transcripts, occurred more ra
American Society of Plant Physiologists.
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14. Host-Pathogen Interactions 1: XVIII. ISOLATION AND BIOLOGICAL ACTIVITY OF GLYCINOL, A PTEROCARPAN PHYTOALEXIN SYNTHESIZED BY SOYBEANS
A previously unrecognized phytoalexin has been isolated from soybean cotyledons that had been infected with bacteria or exposed to ultraviolet light. The phytoalexin has been purified to homogeneity by silica gel flash chromatography and high pressure liquid chromatography. It has been structurally characterized by its ultraviolet, circular dichroism and nuc
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15. Differential induction of chalcone synthase mRNA activity at the onset of phytoalexin accumulation in compatible and incompatible plant-pathogen interactions
Changes in the mRNA activity of chalcone synthase, the first enzyme of phenylpropanoid metabolism specific to flavonoid/isoflavonoid biosynthesis, have been investigated in relation to expression of the phytoalexin defense response in race-cultivar specific interactions between hypocotyls of Phaseolus vulgaris and the partially biotrophic fungus Colletotrich
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16. Differences in the Recognition of Glucan Elicitor Signals between Rice and Soybean: β-Glucan Fragments from the Rice Blast Disease Fungus Pyricularia oryzae That Elicit Phytoalexin Biosynthesis in Suspension-Cultured Rice Cells
Partial acid/enzymatic hydrolysis of the β-(1→3, 1→6)-glucan from the cell walls of the rice blast disease fungus Pyricularia oryzae (Magnaporthe grisea) released elicitor-active fragments that induced phytoalexin biosynthesis in suspension-cultured rice cells. From the digestion of the glucan by an endo-β-(1→3)-glucanase, one highly elicitor-active
American Society of Plant Physiologists.
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17. Involvement of Jasmonic Acid in Elicitor-Induced Phytoalexin Production in Suspension-Cultured Rice Cells.
It has been suggested that jasmonic acid (JA) could be an integral part of a general signal transduction system regulating inducible defense genes in plants. It was reported that treatment with an elicitor (N-acetylchitoheptaose) induced production of phytoalexin in suspension-cultured rice (Oryza sativa L.) cells. In this study, the role of JA in the induct
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18. Elicitor-Induced Association of Isoflavone O-Methyltransferase with Endomembranes Prevents the Formation and 7-O-Methylation of Daidzein during Isoflavonoid Phytoalexin Biosynthesis
The bioactive isoflavonoids of the Leguminosae often are methylated on the 4′-position of their B-rings. Paradoxically, reverse genetic evidence implicates alfalfa isoflavone O-methyltransferase (IOMT) in the biosynthesis of 4′-O-methylated isoflavonoids such as the phytoalexin medicarpin in vivo, whereas biochemical studies indicate that IOMT has strict
American Society of Plant Biologists.
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19. Relationship between Active Oxygen Species, Lipid Peroxidation, Necrosis, and Phytoalexin Production Induced by Elicitins in Nicotiana.
Excised leaves of Nicotiana tabacum var Xanthi and Nicotiana rustica were treated with cryptogein and capsicein, basic and acidic elicitins, respectively. Both compounds induced leaf necrosis, the intensity of which depended on concentration and duration of treatment. N. tabacum var Xanthi was the most sensitive species and cryptogein was the most active eli
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20. Three Genes for Metabolism of the Phytoalexin Maackiain in the Plant Pathogen Nectria haematococca: Meiotic Instability and Relationship to a New Gene for Pisatin Demethylase
Some isolates of the plant-pathogenic fungus Nectria haematococca mating population (MP) VI metabolize maackiain and medicarpin, two antimicrobial compounds (phytoalexins) synthesized by chickpea (Cicer arietinum L.). The enzymatic modifications by the fungus convert the phytoalexins to less toxic derivatives, and this detoxification has been proposed to be
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21. Inhibition of Elicitor-Induced Phytoalexin Formation in Cotton and Soybean Cells by Citrate 1
Addition of an elicitor preparation from Verticillium dahliae to soybean or cotton cell suspension cultures induces the formation of the phytoalexins, glycelollin or sesquiterpene aldehydes, respectively. Recent work (PS Low, PF Heinstein 1986 Arch Biochem Biophys 249: 472-479) has shown that the induction of phytoalexin biosynthesis in these cells is preced
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22. Breakdown of Phosphatidylinositol during the Elicitation of Phytoalexin Production in Cultured Carrot Cells
Elicitor-induced production of the phytoalexin, 6-methoxymellein, in cultured carrot cells was appreciably depressed by the calmodulin inhibitors N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide and trifluoperazine. An inhibitor of Ca2+-phospholipid dependent protein kinase (protein kinase C), 1-(5-isoquinolinesulfonyl)-2-methylpiperazine, also inhibited t
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23. Involvement of de Novo Protein Synthesis, Protein Kinase, Extracellular Ca2+, and Lipoxygenase in Arachidonic Acid Induction of 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Genes and Isoprenoid Accumulation in Potato (Solanum tuberosum L.).
A series of inhibitors were tested to determine the participation of de novo protein synthesis, protein kinase activity, extracellular Ca2+, and lipoxygenase activity in arachidonic acid elicitation of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) gene expression and sesquiterpene phytoalexin biosynthesis in potato (Solanum tuberosum L. cv Kennebec)
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24. Evidence for Sulfhydryl Involvement in Regulation of Phytoalexin Accumulation in Trifolium repens Callus Tissue Cultures 1
White clover (Trifolium repens L.) callus tissue cultures accumulated the phytoalexin medicarpin after treatment with sulfhydryl reagents. After 24-hour exposures to sulfhydryl reagents, maximum obtainable levels of medicarpin, determined by high performance liquid chromatography analysis, were found with 50 millimolar N-ethyl maleimide, 25 millimolar HgCl2,