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Abstract
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| In legume plants, Symbiotic Nitrogen Fixation (conversion of N2 to NH4+) requires a steady supply of molybdenum to synthesize the Iron-Molybdenum cofactor of nitrogenase. Once molybdenum is incorporated from the soil it has to reach bacteroids inside the root nodules cells. The transport of molybdenum from the host plant to the endosymbiotic rhizobia occurs via molybdate transporters. MOT1 family members (1) are likely candidates to mediate molybdate delivery to the nodules, as indicates the role of MtMOT1.3 in molybdate uptake by nitrogen fixing cells (2). Here we have identified MtMOT1.2, a putative molybdate transporter which is located in endodermal cells in roots and nodules. Inmunolocalization studies revealed that MtMOT1.2 was associated with plasma membrane and intracellular membrane systems. There, it would transport molybdate towards the cytosol, as indicated by yeast transport assays. A MtMOT1.2 knockout mutant showed reduced nitrogenase activity and impaired growth compared to wild type plants under symbiotic conditions. Also, the molybdate content in mot1.2 nodules was found to be lower than wild type, indicating that molybdate is not properly reaching nodules. Nitrogenase activity and growth were restored by reintroducing a functional copyof MtMOT1.2 or by molybdate-fortification of nutrient solution. These results support a model in which MtMOT1.2 would mediate molybdate delivery by the vasculature to the nodules. | |
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International
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No |
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Congress
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CBGP Workshop |
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970 |
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Place
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Pozuelo de Alarcón, Madrid |
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Reviewers
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Si |
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ISBN/ISSN
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0000-0000 |
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Start Date
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30/05/2018 |
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End Date
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01/06/2018 |
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From page
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0 |
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To page
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0 |
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CBGP Workshop |