Pseudonodule Formation by Wild-Type and Symbiotic Mutant Medicago truncatula in Response to Auxin Transport Inhibitors
Rhizobium and allied bacteria form symbiotic nitrogen-fixing nodules on legume roots. Plant hormones play key roles in nodule formation. We treated Medicago truncatula roots with auxin transport inhibitors (ATI) N-(1-naphthyl)phthalamic acid (NPA) and 2,3,5-triiodobenzoic acid (TIBA) to induce the f...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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The American Phytopathological Society
2011-11-01
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| Series: | Molecular Plant-Microbe Interactions |
| Online Access: | https://apsjournals.apsnet.org/doi/10.1094/MPMI-04-11-0103 |
| _version_ | 1811291333800755200 |
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| author | Adriana P. Rightmyer Sharon R. Long |
| author_facet | Adriana P. Rightmyer Sharon R. Long |
| author_sort | Adriana P. Rightmyer |
| collection | DOAJ |
| description | Rhizobium and allied bacteria form symbiotic nitrogen-fixing nodules on legume roots. Plant hormones play key roles in nodule formation. We treated Medicago truncatula roots with auxin transport inhibitors (ATI) N-(1-naphthyl)phthalamic acid (NPA) and 2,3,5-triiodobenzoic acid (TIBA) to induce the formation of pseudonodules. M. truncatula mutants defective for rhizobial Nod factor signal transduction still formed pseudonodules in response to ATI. However, a M. truncatula ethylene-insensitive supernodulator, sickle 1-1, did not form pseudonodules in response to TIBA, suggesting that the ethylene response pathway is involved in ATI-induced pseudonodule formation. We compared the transcriptional responses of M. truncatula roots treated with ATI to roots inoculated with Sinorhizobium meliloti. Some genes showed consistently parallel expression in ATI-induced and Rhizobium-induced nodules. For other genes, the transcriptional response of M. truncatula roots 1 and 7 days after ATI treatment was in the opposite direction to roots treated with S. meliloti; then, by 21 days, the transcriptional patterns for the two conditions became similar. We silenced 17 genes that were upregulated in both ATI and S. meliloti treatments to determine their effect on nodule formation. Some gene-silenced roots showed a decrease in nodulation efficiency, suggesting a role in nodule formation but not in later nodule functions. |
| first_indexed | 2024-04-13T04:27:40Z |
| format | Article |
| id | doaj.art-704d812a54c44e7c9e7b0b42ecf296aa |
| institution | Directory Open Access Journal |
| issn | 0894-0282 1943-7706 |
| language | English |
| last_indexed | 2024-04-13T04:27:40Z |
| publishDate | 2011-11-01 |
| publisher | The American Phytopathological Society |
| record_format | Article |
| series | Molecular Plant-Microbe Interactions |
| spelling | doaj.art-704d812a54c44e7c9e7b0b42ecf296aa2022-12-22T03:02:26ZengThe American Phytopathological SocietyMolecular Plant-Microbe Interactions0894-02821943-77062011-11-0124111372138410.1094/MPMI-04-11-0103Pseudonodule Formation by Wild-Type and Symbiotic Mutant Medicago truncatula in Response to Auxin Transport InhibitorsAdriana P. RightmyerSharon R. LongRhizobium and allied bacteria form symbiotic nitrogen-fixing nodules on legume roots. Plant hormones play key roles in nodule formation. We treated Medicago truncatula roots with auxin transport inhibitors (ATI) N-(1-naphthyl)phthalamic acid (NPA) and 2,3,5-triiodobenzoic acid (TIBA) to induce the formation of pseudonodules. M. truncatula mutants defective for rhizobial Nod factor signal transduction still formed pseudonodules in response to ATI. However, a M. truncatula ethylene-insensitive supernodulator, sickle 1-1, did not form pseudonodules in response to TIBA, suggesting that the ethylene response pathway is involved in ATI-induced pseudonodule formation. We compared the transcriptional responses of M. truncatula roots treated with ATI to roots inoculated with Sinorhizobium meliloti. Some genes showed consistently parallel expression in ATI-induced and Rhizobium-induced nodules. For other genes, the transcriptional response of M. truncatula roots 1 and 7 days after ATI treatment was in the opposite direction to roots treated with S. meliloti; then, by 21 days, the transcriptional patterns for the two conditions became similar. We silenced 17 genes that were upregulated in both ATI and S. meliloti treatments to determine their effect on nodule formation. Some gene-silenced roots showed a decrease in nodulation efficiency, suggesting a role in nodule formation but not in later nodule functions.https://apsjournals.apsnet.org/doi/10.1094/MPMI-04-11-0103 |
| spellingShingle | Adriana P. Rightmyer Sharon R. Long Pseudonodule Formation by Wild-Type and Symbiotic Mutant Medicago truncatula in Response to Auxin Transport Inhibitors Molecular Plant-Microbe Interactions |
| title | Pseudonodule Formation by Wild-Type and Symbiotic Mutant Medicago truncatula in Response to Auxin Transport Inhibitors |
| title_full | Pseudonodule Formation by Wild-Type and Symbiotic Mutant Medicago truncatula in Response to Auxin Transport Inhibitors |
| title_fullStr | Pseudonodule Formation by Wild-Type and Symbiotic Mutant Medicago truncatula in Response to Auxin Transport Inhibitors |
| title_full_unstemmed | Pseudonodule Formation by Wild-Type and Symbiotic Mutant Medicago truncatula in Response to Auxin Transport Inhibitors |
| title_short | Pseudonodule Formation by Wild-Type and Symbiotic Mutant Medicago truncatula in Response to Auxin Transport Inhibitors |
| title_sort | pseudonodule formation by wild type and symbiotic mutant medicago truncatula in response to auxin transport inhibitors |
| url | https://apsjournals.apsnet.org/doi/10.1094/MPMI-04-11-0103 |
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