Phytohormone Profile of <i>Medicago</i> in Response to Mycorrhizal Fungi, Aphids, and Gibberellic Acid
Although gibberellic acid (GA) is widely used in agriculture, it is unclear whether exogenous GA makes aphid-infested, mycorrhizal plants more susceptible to herbivory. This study investigates the role of GA in modulating defenses in barrel medic plants (<i>Medicago truncatula</i>) that...
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| Format: | Article |
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MDPI AG
2022-03-01
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| Series: | Plants |
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| Online Access: | https://www.mdpi.com/2223-7747/11/6/720 |
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| author | Drew Olson Hannah M. Berry Jamie D. Riggs Cristiana T. Argueso Susana Karen Gomez |
| author_facet | Drew Olson Hannah M. Berry Jamie D. Riggs Cristiana T. Argueso Susana Karen Gomez |
| author_sort | Drew Olson |
| collection | DOAJ |
| description | Although gibberellic acid (GA) is widely used in agriculture, it is unclear whether exogenous GA makes aphid-infested, mycorrhizal plants more susceptible to herbivory. This study investigates the role of GA in modulating defenses in barrel medic plants (<i>Medicago truncatula</i>) that are infested with pea aphids (<i>Acyrthosiphon pisum</i>) and colonized by the beneficial symbiont <i>Rhizophagus intraradices</i>. Mock- and <i>R. intraradices</i>-inoculated potted plants were grown in a topsoil: sand mix for 42 days and were treated with GA or solvent. Subsequently, plants were exposed to herbivory or no aphid herbivory for 36 h and 7 days. Afterwards, plant growth parameters, aphid fitness, and foliar phytohormone concentrations were measured. The results revealed that GA regulates plant defenses during arbuscular mycorrhizal (AM) fungus–plant–aphid interactions as aphids that fed for 7 days on mycorrhizal, GA-untreated plants weighed more than those that fed on mycorrhizal, GA-treated plants. No major differences were detected in phytohormone levels at 36 h. Overall, mycorrhizal plants showed more shoot biomass compared to non-mycorrhizal controls. The arbuscule density and fungal biomass of <i>R. intraradices</i> were not altered by exogenous GA and aphid herbivory based on molecular markers. This study indicates that exogenous GA may help reduce aphid fitness when feeding on mycorrhizal plants. |
| first_indexed | 2024-03-09T12:56:25Z |
| format | Article |
| id | doaj.art-f2b1f6f5f5b0432694398f3a8505aac4 |
| institution | Directory Open Access Journal |
| issn | 2223-7747 |
| language | English |
| last_indexed | 2024-03-09T12:56:25Z |
| publishDate | 2022-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Plants |
| spelling | doaj.art-f2b1f6f5f5b0432694398f3a8505aac42023-11-30T22:00:08ZengMDPI AGPlants2223-77472022-03-0111672010.3390/plants11060720Phytohormone Profile of <i>Medicago</i> in Response to Mycorrhizal Fungi, Aphids, and Gibberellic AcidDrew Olson0Hannah M. Berry1Jamie D. Riggs2Cristiana T. Argueso3Susana Karen Gomez4School of Biological Sciences, University of Northern Colorado, Greeley, CO 80639, USADepartment of Agricultural Biology, Colorado State University, Fort Collins, CO 80523, USASchool of Professional Studies, Northwestern University, Evanston, IL 60208, USADepartment of Agricultural Biology, Colorado State University, Fort Collins, CO 80523, USASchool of Biological Sciences, University of Northern Colorado, Greeley, CO 80639, USAAlthough gibberellic acid (GA) is widely used in agriculture, it is unclear whether exogenous GA makes aphid-infested, mycorrhizal plants more susceptible to herbivory. This study investigates the role of GA in modulating defenses in barrel medic plants (<i>Medicago truncatula</i>) that are infested with pea aphids (<i>Acyrthosiphon pisum</i>) and colonized by the beneficial symbiont <i>Rhizophagus intraradices</i>. Mock- and <i>R. intraradices</i>-inoculated potted plants were grown in a topsoil: sand mix for 42 days and were treated with GA or solvent. Subsequently, plants were exposed to herbivory or no aphid herbivory for 36 h and 7 days. Afterwards, plant growth parameters, aphid fitness, and foliar phytohormone concentrations were measured. The results revealed that GA regulates plant defenses during arbuscular mycorrhizal (AM) fungus–plant–aphid interactions as aphids that fed for 7 days on mycorrhizal, GA-untreated plants weighed more than those that fed on mycorrhizal, GA-treated plants. No major differences were detected in phytohormone levels at 36 h. Overall, mycorrhizal plants showed more shoot biomass compared to non-mycorrhizal controls. The arbuscule density and fungal biomass of <i>R. intraradices</i> were not altered by exogenous GA and aphid herbivory based on molecular markers. This study indicates that exogenous GA may help reduce aphid fitness when feeding on mycorrhizal plants.https://www.mdpi.com/2223-7747/11/6/720mycorrhizal symbiosispea aphidsphytohormonesplant susceptibility |
| spellingShingle | Drew Olson Hannah M. Berry Jamie D. Riggs Cristiana T. Argueso Susana Karen Gomez Phytohormone Profile of <i>Medicago</i> in Response to Mycorrhizal Fungi, Aphids, and Gibberellic Acid Plants mycorrhizal symbiosis pea aphids phytohormones plant susceptibility |
| title | Phytohormone Profile of <i>Medicago</i> in Response to Mycorrhizal Fungi, Aphids, and Gibberellic Acid |
| title_full | Phytohormone Profile of <i>Medicago</i> in Response to Mycorrhizal Fungi, Aphids, and Gibberellic Acid |
| title_fullStr | Phytohormone Profile of <i>Medicago</i> in Response to Mycorrhizal Fungi, Aphids, and Gibberellic Acid |
| title_full_unstemmed | Phytohormone Profile of <i>Medicago</i> in Response to Mycorrhizal Fungi, Aphids, and Gibberellic Acid |
| title_short | Phytohormone Profile of <i>Medicago</i> in Response to Mycorrhizal Fungi, Aphids, and Gibberellic Acid |
| title_sort | phytohormone profile of i medicago i in response to mycorrhizal fungi aphids and gibberellic acid |
| topic | mycorrhizal symbiosis pea aphids phytohormones plant susceptibility |
| url | https://www.mdpi.com/2223-7747/11/6/720 |
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