Nutrition vs association: plant defenses are altered by arbuscular mycorrhizal fungi association not by nutritional provisioning alone
Abstract Background While it is known that arbuscular mycorrhizal fungi (AMF) can improve nutrient acquisition and herbivore resistance in crops, the mechanisms by which AMF influence plant defense remain unknown. Plants respond to herbivory with a cascade of gene expression and phytochemical biosyn...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2022-08-01
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| Series: | BMC Plant Biology |
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| Online Access: | https://doi.org/10.1186/s12870-022-03795-3 |
| _version_ | 1811340189069475840 |
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| author | Chase A. Stratton Swayamjit Ray Brosi A. Bradley Jason P. Kaye Jared G. Ali Ebony G. Murrell |
| author_facet | Chase A. Stratton Swayamjit Ray Brosi A. Bradley Jason P. Kaye Jared G. Ali Ebony G. Murrell |
| author_sort | Chase A. Stratton |
| collection | DOAJ |
| description | Abstract Background While it is known that arbuscular mycorrhizal fungi (AMF) can improve nutrient acquisition and herbivore resistance in crops, the mechanisms by which AMF influence plant defense remain unknown. Plants respond to herbivory with a cascade of gene expression and phytochemical biosynthesis. Given that the production of defensive phytochemicals requires nutrients, a commonly invoked hypothesis is that the improvement to plant defense when grown with AMF is simply due to an increased availability of nutrients. An alternative hypothesis is that the AMF effect on herbivory is due to changes in plant defense gene expression that are not simply due to nutrient availability. In this study, we tested whether changes in plant defenses are regulated by nutritional provisioning alone or the response of plant to AMF associations. Maize plants grown with or without AMF and with one of three fertilizer treatments (standard, 2 × nitrogen, or 2 × phosphorous) were infested with fall armyworm (Spodoptera frugiperda; FAW) for 72 h. We measured general plant characteristics (e.g. height, number of leaves), relative gene expression (rtPCR) of three defensive genes (lox3, mpi, and pr5), total plant N and P nutrient content, and change in FAW mass per plant. Results We found that AMF drove the defense response of maize by increasing the expression of mpi and pr5. Furthermore, while AMF increased the total phosphorous content of maize it had no impact on maize nitrogen. Fertilization alone did not alter upregulation of any of the 3 induced defense genes tested, suggesting the mechanism through which AMF upregulate defenses is not solely via increased N or P plant nutrition. Conclusion This work supports that maize defense may be optimized by AMF associations alone, reducing the need for artificial inputs when managing FAW. |
| first_indexed | 2024-04-13T18:38:13Z |
| format | Article |
| id | doaj.art-b73e515858fd4748a61b899bbec90293 |
| institution | Directory Open Access Journal |
| issn | 1471-2229 |
| language | English |
| last_indexed | 2024-04-13T18:38:13Z |
| publishDate | 2022-08-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Plant Biology |
| spelling | doaj.art-b73e515858fd4748a61b899bbec902932022-12-22T02:34:49ZengBMCBMC Plant Biology1471-22292022-08-0122111010.1186/s12870-022-03795-3Nutrition vs association: plant defenses are altered by arbuscular mycorrhizal fungi association not by nutritional provisioning aloneChase A. Stratton0Swayamjit Ray1Brosi A. Bradley2Jason P. Kaye3Jared G. Ali4Ebony G. Murrell5The Land InstituteDepartment of Entomology, Pennsylvania State UniversityDepartment of Ecosystem Science and Management, Pennsylvania State UniversityDepartment of Ecosystem Science and Management, Pennsylvania State UniversityDepartment of Entomology, Pennsylvania State UniversityThe Land InstituteAbstract Background While it is known that arbuscular mycorrhizal fungi (AMF) can improve nutrient acquisition and herbivore resistance in crops, the mechanisms by which AMF influence plant defense remain unknown. Plants respond to herbivory with a cascade of gene expression and phytochemical biosynthesis. Given that the production of defensive phytochemicals requires nutrients, a commonly invoked hypothesis is that the improvement to plant defense when grown with AMF is simply due to an increased availability of nutrients. An alternative hypothesis is that the AMF effect on herbivory is due to changes in plant defense gene expression that are not simply due to nutrient availability. In this study, we tested whether changes in plant defenses are regulated by nutritional provisioning alone or the response of plant to AMF associations. Maize plants grown with or without AMF and with one of three fertilizer treatments (standard, 2 × nitrogen, or 2 × phosphorous) were infested with fall armyworm (Spodoptera frugiperda; FAW) for 72 h. We measured general plant characteristics (e.g. height, number of leaves), relative gene expression (rtPCR) of three defensive genes (lox3, mpi, and pr5), total plant N and P nutrient content, and change in FAW mass per plant. Results We found that AMF drove the defense response of maize by increasing the expression of mpi and pr5. Furthermore, while AMF increased the total phosphorous content of maize it had no impact on maize nitrogen. Fertilization alone did not alter upregulation of any of the 3 induced defense genes tested, suggesting the mechanism through which AMF upregulate defenses is not solely via increased N or P plant nutrition. Conclusion This work supports that maize defense may be optimized by AMF associations alone, reducing the need for artificial inputs when managing FAW.https://doi.org/10.1186/s12870-022-03795-3Arbuscular mycorrhizal fungiSpodoptera frugiperdaZea maysGene expressionInduced defenseNutrient digests |
| spellingShingle | Chase A. Stratton Swayamjit Ray Brosi A. Bradley Jason P. Kaye Jared G. Ali Ebony G. Murrell Nutrition vs association: plant defenses are altered by arbuscular mycorrhizal fungi association not by nutritional provisioning alone BMC Plant Biology Arbuscular mycorrhizal fungi Spodoptera frugiperda Zea mays Gene expression Induced defense Nutrient digests |
| title | Nutrition vs association: plant defenses are altered by arbuscular mycorrhizal fungi association not by nutritional provisioning alone |
| title_full | Nutrition vs association: plant defenses are altered by arbuscular mycorrhizal fungi association not by nutritional provisioning alone |
| title_fullStr | Nutrition vs association: plant defenses are altered by arbuscular mycorrhizal fungi association not by nutritional provisioning alone |
| title_full_unstemmed | Nutrition vs association: plant defenses are altered by arbuscular mycorrhizal fungi association not by nutritional provisioning alone |
| title_short | Nutrition vs association: plant defenses are altered by arbuscular mycorrhizal fungi association not by nutritional provisioning alone |
| title_sort | nutrition vs association plant defenses are altered by arbuscular mycorrhizal fungi association not by nutritional provisioning alone |
| topic | Arbuscular mycorrhizal fungi Spodoptera frugiperda Zea mays Gene expression Induced defense Nutrient digests |
| url | https://doi.org/10.1186/s12870-022-03795-3 |
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