Hypaphorine from the Ectomycorrhizal Fungus Pisolithus tinctorius Counteracts Activities of Indole-3-Acetic Acid and Ethylene but Not Synthetic Auxins in Eucalypt Seedlings
Very little is known about the molecules regulating the interaction between plants and ectomycorrhizal fungi during root colonization. The role of fungal auxin in ectomycorrhiza has repeatedly been suggested and questioned, suggesting that, if fungal auxin controls some steps of colonized root devel...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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The American Phytopathological Society
2000-02-01
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| Series: | Molecular Plant-Microbe Interactions |
| Online Access: | https://apsjournals.apsnet.org/doi/10.1094/MPMI.2000.13.2.151 |
| _version_ | 1818915183442001920 |
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| author | Franck Anicet Ditengou Frédéric Lapeyrie |
| author_facet | Franck Anicet Ditengou Frédéric Lapeyrie |
| author_sort | Franck Anicet Ditengou |
| collection | DOAJ |
| description | Very little is known about the molecules regulating the interaction between plants and ectomycorrhizal fungi during root colonization. The role of fungal auxin in ectomycorrhiza has repeatedly been suggested and questioned, suggesting that, if fungal auxin controls some steps of colonized root development, its activity might be tightly controlled in time and in space by plant and/or fungal regulatory mechanisms. We demonstrate that fungal hypaphorine, the betaine of tryptophan, counteracts the activity of indole-3-acetic acid (IAA) on eucalypt tap root elongation but does not affect the activity of the IAA analogs 2,4-D ((2,4-dichlorophenoxy)acetic acid) or NAA (1-naphthaleneacetic acid). These data suggest that IAA and hypaphorine interact during the very early steps of the IAA perception or signal transduction pathway. Furthermore, while seedling treatment with 1-amincocyclopro-pane-1-carboxylic acid (ACC), the precursor of ethylene, results in formation of a hypocotyl apical hook, hypaphorine application as well as root colonization by Pisolithus tinctorius, a hypaphorine-accumulating ectomycorrhizal fungus, stimulated hook opening. Hypaphorine counteraction with ACC is likely a consequence of hypaphorine interaction with IAA. In most plant-microbe interactions studied, the interactions result in increased auxin synthesis or auxin accumulation in plant tissues. The P. tinctorius / eucalypt interaction is intriguing because in this interaction the microbe down-regulates the auxin activity in the host plant. Hypaphorine might be the first specific IAA antagonist identified. |
| first_indexed | 2024-12-19T23:58:14Z |
| format | Article |
| id | doaj.art-a0ee2c74cf724539905a7fabd175d193 |
| institution | Directory Open Access Journal |
| issn | 0894-0282 1943-7706 |
| language | English |
| last_indexed | 2024-12-19T23:58:14Z |
| publishDate | 2000-02-01 |
| publisher | The American Phytopathological Society |
| record_format | Article |
| series | Molecular Plant-Microbe Interactions |
| spelling | doaj.art-a0ee2c74cf724539905a7fabd175d1932022-12-21T20:00:56ZengThe American Phytopathological SocietyMolecular Plant-Microbe Interactions0894-02821943-77062000-02-0113215115810.1094/MPMI.2000.13.2.151Hypaphorine from the Ectomycorrhizal Fungus Pisolithus tinctorius Counteracts Activities of Indole-3-Acetic Acid and Ethylene but Not Synthetic Auxins in Eucalypt SeedlingsFranck Anicet DitengouFrédéric LapeyrieVery little is known about the molecules regulating the interaction between plants and ectomycorrhizal fungi during root colonization. The role of fungal auxin in ectomycorrhiza has repeatedly been suggested and questioned, suggesting that, if fungal auxin controls some steps of colonized root development, its activity might be tightly controlled in time and in space by plant and/or fungal regulatory mechanisms. We demonstrate that fungal hypaphorine, the betaine of tryptophan, counteracts the activity of indole-3-acetic acid (IAA) on eucalypt tap root elongation but does not affect the activity of the IAA analogs 2,4-D ((2,4-dichlorophenoxy)acetic acid) or NAA (1-naphthaleneacetic acid). These data suggest that IAA and hypaphorine interact during the very early steps of the IAA perception or signal transduction pathway. Furthermore, while seedling treatment with 1-amincocyclopro-pane-1-carboxylic acid (ACC), the precursor of ethylene, results in formation of a hypocotyl apical hook, hypaphorine application as well as root colonization by Pisolithus tinctorius, a hypaphorine-accumulating ectomycorrhizal fungus, stimulated hook opening. Hypaphorine counteraction with ACC is likely a consequence of hypaphorine interaction with IAA. In most plant-microbe interactions studied, the interactions result in increased auxin synthesis or auxin accumulation in plant tissues. The P. tinctorius / eucalypt interaction is intriguing because in this interaction the microbe down-regulates the auxin activity in the host plant. Hypaphorine might be the first specific IAA antagonist identified.https://apsjournals.apsnet.org/doi/10.1094/MPMI.2000.13.2.151 |
| spellingShingle | Franck Anicet Ditengou Frédéric Lapeyrie Hypaphorine from the Ectomycorrhizal Fungus Pisolithus tinctorius Counteracts Activities of Indole-3-Acetic Acid and Ethylene but Not Synthetic Auxins in Eucalypt Seedlings Molecular Plant-Microbe Interactions |
| title | Hypaphorine from the Ectomycorrhizal Fungus Pisolithus tinctorius Counteracts Activities of Indole-3-Acetic Acid and Ethylene but Not Synthetic Auxins in Eucalypt Seedlings |
| title_full | Hypaphorine from the Ectomycorrhizal Fungus Pisolithus tinctorius Counteracts Activities of Indole-3-Acetic Acid and Ethylene but Not Synthetic Auxins in Eucalypt Seedlings |
| title_fullStr | Hypaphorine from the Ectomycorrhizal Fungus Pisolithus tinctorius Counteracts Activities of Indole-3-Acetic Acid and Ethylene but Not Synthetic Auxins in Eucalypt Seedlings |
| title_full_unstemmed | Hypaphorine from the Ectomycorrhizal Fungus Pisolithus tinctorius Counteracts Activities of Indole-3-Acetic Acid and Ethylene but Not Synthetic Auxins in Eucalypt Seedlings |
| title_short | Hypaphorine from the Ectomycorrhizal Fungus Pisolithus tinctorius Counteracts Activities of Indole-3-Acetic Acid and Ethylene but Not Synthetic Auxins in Eucalypt Seedlings |
| title_sort | hypaphorine from the ectomycorrhizal fungus pisolithus tinctorius counteracts activities of indole 3 acetic acid and ethylene but not synthetic auxins in eucalypt seedlings |
| url | https://apsjournals.apsnet.org/doi/10.1094/MPMI.2000.13.2.151 |
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