Nicotianamine synthase 2 is required for symbiotic nitrogen fixation in Medicago truncatula nodules
Nicotianamine synthase 2 is required for symbiotic nitrogen fixation in Medicago truncatula nodules
SUMMARY Symbiotic nitrogen fixation carried out by the interaction between legumes and diazotrophic bacteria known as rhizobia requires of relatively large levels of transition metals. These elements act as cofactors of many key enzymes involved in this process. Metallic micronutrients are obtained from soil by the roots and directed to sink organs by the vasculature, in a process participated by a number of metal transporters and small organic molecules that mediate metal delivery in the plant fluids. Among the later, nicotianamine is one of the most important. Synthesized by nicotianamine synthases (NAS), this non-proteinogenic amino acid forms metal complexes participating in intracellular metal homeostasis and long-distance metal trafficking. Here we characterized the NAS2 gene from model legume Medicago truncatula. MtNAS2 is located in the root vasculature and in all nodule tissues in the infection and fixation zones. Symbiotic nitrogen fixation requires of MtNAS2 function, as indicated by the loss of nitrogenase activity in the insertional mutant nas2-1, a phenotype reverted by reintroduction of a wild-type copy of MtNAS2. This would be the result of the altered iron distribution in nas2-1 nodules, as indicated by X-ray fluorescence studies. Moreover, iron speciation is also affected in these nodules. These data suggest a role of nicotianamine in iron delivery for symbiotic nitrogen fixation. Significance StatementNicotianamine synthesis mediated by MtNAS2 is important for iron allocation for symbiotic nitrogen fixation by rhizobia in Medicago truncatula root nodules.
Escudero Viviana、Tejada-Jim¨|nez Manuel、Arg¨1ello Jos¨| M.、Castillo-Michel Hiram、Imperial Juan、Larue Camile、Gonz¨￠lez-Guerrero Manuel、Abad¨aa Javier、Wen Jiangqi、Mysore Kirankumar S.、¨￠lvarez-Fern¨￠ndez Ana、del Sastre Eric、Novoa-Aponte Lorena、Abreu Isidro
Centro de Biotecnolog¨aa y Gen¨?mica de Plantas (UPM-INIA), Universidad Polit¨|cnica de MadridCentro de Biotecnolog¨aa y Gen¨?mica de Plantas (UPM-INIA), Universidad Polit¨|cnica de MadridWorcester Polytechnic InstituteID21 Beamline. European Synchrotron Radiation FacilityInstituto de Ciencias Agrarias, Consejo Superior de Investigaciones Cient¨aficasEcoLab, Universit¨| de ToulouseCentro de Biotecnolog¨aa y Gen¨?mica de Plantas (UPM-INIA), Universidad Polit¨|cnica de Madrid||Escuela T¨|cnica Superior de Ingenier¨aa Agron¨?mica, Alimentaria y de Biosistemas, Universidad Polit¨|cnica de MadridEstaci¨?n Experimental de Aula Dei, Consejo Superior de Investigaciones Cient¨aficasNoble Research InstituteNoble Research InstituteEstaci¨?n Experimental de Aula Dei, Consejo Superior de Investigaciones Cient¨aficasCentro de Biotecnolog¨aa y Gen¨?mica de Plantas (UPM-INIA), Universidad Polit¨|cnica de MadridWorcester Polytechnic InstituteCentro de Biotecnolog¨aa y Gen¨?mica de Plantas (UPM-INIA), Universidad Polit¨|cnica de Madrid
分子生物学植物学生物化学
ironmetal homeostasislegumeNAS
Escudero Viviana,Tejada-Jim¨|nez Manuel,Arg¨1ello Jos¨| M.,Castillo-Michel Hiram,Imperial Juan,Larue Camile,Gonz¨￠lez-Guerrero Manuel,Abad¨aa Javier,Wen Jiangqi,Mysore Kirankumar S.,¨￠lvarez-Fern¨￠ndez Ana,del Sastre Eric,Novoa-Aponte Lorena,Abreu Isidro.Nicotianamine synthase 2 is required for symbiotic nitrogen fixation in Medicago truncatula nodules[EB/OL].(2025-03-28)[2025-04-28].https://www.biorxiv.org/content/10.1101/717983.点此复制
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