Protein phosphatase inhibitors activate anti-fungal defence responses of soybean cotyledons and cell cultures

Carol MacKintosh, Gary D. Lyon, Robert W. MacKintosh

    Research output: Contribution to journalArticle

    84 Citations (Scopus)

    Abstract

    The application of a variety of structurally different protein phosphatase inhibitors (okadaic acid, acanthifolicin, microcystins, nodularin, tautomycin, calyculin A, cantharidin and endothall) to cut surfaces of soybean cotyledons (Glycine max L.) resulted in the production of isoflavonoid phytoalexins (plant defence compounds). Daidzein was the predominant isoflavonoid produced by soybean cotyledons in response to protein phosphatase inhibitors. In contrast, several isoflavonoid phytoalexins were seen after application of either an elicitor beta-glucan fraction isolated from yeast extract or hepta-(1-->3, 1-->6)-beta-glucoside which is the most potent elicitor-active component isolated from the soybean pathogen Phytophthora megasperma f. sp. glycinea. Isoflavonoid production in response to either protein phosphatase inhibitors or elicitors reached a maximum after 2G-24 h. The addition of protein phosphatase inhibitors to a soybean cell suspension culture induced the expression of phenylalanine ammonia-lyase (PAL), the first enzyme in the isoflavonoid blosynthetic pathway. Induction of PAL activity was blocked by protein synthesis inhibitors, cycloheximide or anisomysin, and largely prevented by a protein kinase inhibitor, K252a. Another common response of plant cells to fungal elicitation, alkalinization of the soybean cell culture media, was induced within minutes in response to protein phosphatase inhibitors and was largely prevented by K252a.

    These studies suggest a direct role for phosphorylation in activation of plasma membrane ion flux(es), whereas the longer-term effects of protein phosphatase inhibitors on isoflavonoid production and PAL expression could be due to either direct effects of increased protein phosphorylation, or the secondary consequences of other phosphorylation-induced cellular changes. They aiso indicate that protein phosphatase inhibitors are likely to be of general use in investigating mechanisms of plant responses to environmental stimull.

    Original languageEnglish
    Pages (from-to)137-147
    Number of pages11
    JournalPlant Journal
    Volume5
    Issue number1
    DOIs
    Publication statusPublished - 1994

    Cite this

    @article{4a74aba061cc4eaa93728d64111712b9,
    title = "Protein phosphatase inhibitors activate anti-fungal defence responses of soybean cotyledons and cell cultures",
    abstract = "The application of a variety of structurally different protein phosphatase inhibitors (okadaic acid, acanthifolicin, microcystins, nodularin, tautomycin, calyculin A, cantharidin and endothall) to cut surfaces of soybean cotyledons (Glycine max L.) resulted in the production of isoflavonoid phytoalexins (plant defence compounds). Daidzein was the predominant isoflavonoid produced by soybean cotyledons in response to protein phosphatase inhibitors. In contrast, several isoflavonoid phytoalexins were seen after application of either an elicitor beta-glucan fraction isolated from yeast extract or hepta-(1-->3, 1-->6)-beta-glucoside which is the most potent elicitor-active component isolated from the soybean pathogen Phytophthora megasperma f. sp. glycinea. Isoflavonoid production in response to either protein phosphatase inhibitors or elicitors reached a maximum after 2G-24 h. The addition of protein phosphatase inhibitors to a soybean cell suspension culture induced the expression of phenylalanine ammonia-lyase (PAL), the first enzyme in the isoflavonoid blosynthetic pathway. Induction of PAL activity was blocked by protein synthesis inhibitors, cycloheximide or anisomysin, and largely prevented by a protein kinase inhibitor, K252a. Another common response of plant cells to fungal elicitation, alkalinization of the soybean cell culture media, was induced within minutes in response to protein phosphatase inhibitors and was largely prevented by K252a.These studies suggest a direct role for phosphorylation in activation of plasma membrane ion flux(es), whereas the longer-term effects of protein phosphatase inhibitors on isoflavonoid production and PAL expression could be due to either direct effects of increased protein phosphorylation, or the secondary consequences of other phosphorylation-induced cellular changes. They aiso indicate that protein phosphatase inhibitors are likely to be of general use in investigating mechanisms of plant responses to environmental stimull.",
    author = "Carol MacKintosh and Lyon, {Gary D.} and MacKintosh, {Robert W.}",
    year = "1994",
    doi = "10.1046/j.1365-313X.1994.5010137.x",
    language = "English",
    volume = "5",
    pages = "137--147",
    journal = "Plant Journal",
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    Protein phosphatase inhibitors activate anti-fungal defence responses of soybean cotyledons and cell cultures. / MacKintosh, Carol; Lyon, Gary D.; MacKintosh, Robert W.

    In: Plant Journal, Vol. 5, No. 1, 1994, p. 137-147.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Protein phosphatase inhibitors activate anti-fungal defence responses of soybean cotyledons and cell cultures

    AU - MacKintosh, Carol

    AU - Lyon, Gary D.

    AU - MacKintosh, Robert W.

    PY - 1994

    Y1 - 1994

    N2 - The application of a variety of structurally different protein phosphatase inhibitors (okadaic acid, acanthifolicin, microcystins, nodularin, tautomycin, calyculin A, cantharidin and endothall) to cut surfaces of soybean cotyledons (Glycine max L.) resulted in the production of isoflavonoid phytoalexins (plant defence compounds). Daidzein was the predominant isoflavonoid produced by soybean cotyledons in response to protein phosphatase inhibitors. In contrast, several isoflavonoid phytoalexins were seen after application of either an elicitor beta-glucan fraction isolated from yeast extract or hepta-(1-->3, 1-->6)-beta-glucoside which is the most potent elicitor-active component isolated from the soybean pathogen Phytophthora megasperma f. sp. glycinea. Isoflavonoid production in response to either protein phosphatase inhibitors or elicitors reached a maximum after 2G-24 h. The addition of protein phosphatase inhibitors to a soybean cell suspension culture induced the expression of phenylalanine ammonia-lyase (PAL), the first enzyme in the isoflavonoid blosynthetic pathway. Induction of PAL activity was blocked by protein synthesis inhibitors, cycloheximide or anisomysin, and largely prevented by a protein kinase inhibitor, K252a. Another common response of plant cells to fungal elicitation, alkalinization of the soybean cell culture media, was induced within minutes in response to protein phosphatase inhibitors and was largely prevented by K252a.These studies suggest a direct role for phosphorylation in activation of plasma membrane ion flux(es), whereas the longer-term effects of protein phosphatase inhibitors on isoflavonoid production and PAL expression could be due to either direct effects of increased protein phosphorylation, or the secondary consequences of other phosphorylation-induced cellular changes. They aiso indicate that protein phosphatase inhibitors are likely to be of general use in investigating mechanisms of plant responses to environmental stimull.

    AB - The application of a variety of structurally different protein phosphatase inhibitors (okadaic acid, acanthifolicin, microcystins, nodularin, tautomycin, calyculin A, cantharidin and endothall) to cut surfaces of soybean cotyledons (Glycine max L.) resulted in the production of isoflavonoid phytoalexins (plant defence compounds). Daidzein was the predominant isoflavonoid produced by soybean cotyledons in response to protein phosphatase inhibitors. In contrast, several isoflavonoid phytoalexins were seen after application of either an elicitor beta-glucan fraction isolated from yeast extract or hepta-(1-->3, 1-->6)-beta-glucoside which is the most potent elicitor-active component isolated from the soybean pathogen Phytophthora megasperma f. sp. glycinea. Isoflavonoid production in response to either protein phosphatase inhibitors or elicitors reached a maximum after 2G-24 h. The addition of protein phosphatase inhibitors to a soybean cell suspension culture induced the expression of phenylalanine ammonia-lyase (PAL), the first enzyme in the isoflavonoid blosynthetic pathway. Induction of PAL activity was blocked by protein synthesis inhibitors, cycloheximide or anisomysin, and largely prevented by a protein kinase inhibitor, K252a. Another common response of plant cells to fungal elicitation, alkalinization of the soybean cell culture media, was induced within minutes in response to protein phosphatase inhibitors and was largely prevented by K252a.These studies suggest a direct role for phosphorylation in activation of plasma membrane ion flux(es), whereas the longer-term effects of protein phosphatase inhibitors on isoflavonoid production and PAL expression could be due to either direct effects of increased protein phosphorylation, or the secondary consequences of other phosphorylation-induced cellular changes. They aiso indicate that protein phosphatase inhibitors are likely to be of general use in investigating mechanisms of plant responses to environmental stimull.

    U2 - 10.1046/j.1365-313X.1994.5010137.x

    DO - 10.1046/j.1365-313X.1994.5010137.x

    M3 - Article

    VL - 5

    SP - 137

    EP - 147

    JO - Plant Journal

    JF - Plant Journal

    SN - 0960-7412

    IS - 1

    ER -