A dual regulatory role for the arbuscular mycorrhizal master regulator RAM1 in tomato
The REQUIRED FOR ARBUSCULAR MYCORRHIZATION1 (RAM1) transcription factor from the GRAS family is well known for its role as a master regulator of the arbuscular mycorrhizal (AM) symbiosis in dicotyledonous and monocotyledonous species, being essential in transcriptional reprogramming for the developm...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/371695 |
| Acceso en línea: | http://hdl.handle.net/10261/371695 |
| Access Level: | acceso abierto |
| Palabra clave: | Micorriza arbuscular GRAS RAM1 Estrigolactonas Tomate Regulación transcripcional |
| Sumario: | The REQUIRED FOR ARBUSCULAR MYCORRHIZATION1 (RAM1) transcription factor from the GRAS family is well known for its role as a master regulator of the arbuscular mycorrhizal (AM) symbiosis in dicotyledonous and monocotyledonous species, being essential in transcriptional reprogramming for the development and functionality of the arbuscules. In tomato, SlGRAS27 is the putative orthologue of RAM1 (here named SlRAM1), but has not yet been characterized. A reduced colonization of the root and impaired arbuscule formation were observed in SlRAM1-silenced plants, confirming the functional conservation of the RAM1 orthologue in tomato. However, unexpectedly, SlRAM1overexpressing (UBIL:SlRAM1) plants also showed decreased mycorrhizal colonization. Analysis of non-mycorrhizal UBIL:SlRAM1 roots revealed an overall regulation of AM-related genes and a reduction of strigolactone biosynthesis. Moreover, external application of the strigolactone analogue GR24 almost completely reversed the negative effects of SlRAM1 overexpression on the frequency of mycorrhization. However, it only partially recovered the pattern of arbuscule distribution observed in control plants. Our results strongly suggest that SlRAM1 has a dual regulatory role during mycorrhization and, in addition to its recognized action as a positive regulator of arbuscule development, it is also involved in different mechanisms for the negative regulation of mycorrhization, including the repression of strigolactone biosynthesis. |
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