MtMOT1.2 is responsible for molybdate supply to Medicago truncatula nodules

MtMOT1.2 is responsible for molybdate supply to Medicago truncatula nodules

ABSTRACT 27 Symbiotic nitrogen fixation in legume root nodules requires a steady supply of 28 molybdenum for synthesis of the iron-molybdenum cofactor of nitrogenase. This nutrient 29 has to be provided by the host plant from the soil, crossing several symplastically 30 disconnected compartments through molybdate transporters, including members of the 31 MOT1 family. MtMOT1.2 is a Medicago truncatula MOT1 family member located in 32 the endodermal cells in roots and nodules. Immunolocalization of a tagged MtMOT1.2 33 indicates that it is associated to the plasma membrane and to intracellular membrane 34 systems, where it would be transporting molybdate towards the cytosol, as indicated in 35 yeast transport assays. Loss-of-function mot1.2-1 mutant showed reduced growth 36 compared to wild-type plants when nitrogen fixation was required, but not when nitrogen 37 was provided as nitrate. While no effect on molybdenum-dependent nitrate reductase 38 activity was observed, nitrogenase activity was severely affected, explaining the observed 39 difference of growth depending on nitrogen source. This phenotype was the result of 40 molybdate not reaching the nitrogen-fixing nodules, since genetic complementation with 41 a wild-type MtMOT1.2 gene or molybdate-fortification of the nutrient solution, both 42 restored wild-type levels of growth and nitrogenase activity. These results support a 43 model in which MtMOT1.2 would mediate molybdate delivery by the vasculature into 44 the nodules. 45 46

Saved in:
Bibliographic Details
Main Author: Patricia Gil-Díez1, Manuel Tejada-Jiménez1,2, Javier León-Mediavilla1, Jiangqi Wen, 7 Kirankumar S. Mysore3, Juan Imperial1,4, Manuel González-Guerrero1,5
Format: artículo biblioteca
Published: 2019-01
Subjects:symbiotic nitrogen fixation, rhizobia, plant nutrition, legume,
Online Access:http://hdl.handle.net/10261/205331
Tags: Add Tag
No Tags, Be the first to tag this record!
id dig-ica-es-10261-205331
record_format koha
institution ICA ES
collection DSpace
country España
countrycode ES
component Bibliográfico
access En linea
databasecode dig-ica-es
tag biblioteca
region Europa del Sur
libraryname Biblioteca del ICA España
topic symbiotic nitrogen fixation, rhizobia, plant nutrition, legume
symbiotic nitrogen fixation, rhizobia, plant nutrition, legume
spellingShingle symbiotic nitrogen fixation, rhizobia, plant nutrition, legume
symbiotic nitrogen fixation, rhizobia, plant nutrition, legume
Patricia Gil-Díez1, Manuel Tejada-Jiménez1,2, Javier León-Mediavilla1, Jiangqi Wen, 7 Kirankumar S. Mysore3, Juan Imperial1,4, Manuel González-Guerrero1,5
MtMOT1.2 is responsible for molybdate supply to Medicago truncatula nodules
description ABSTRACT 27 Symbiotic nitrogen fixation in legume root nodules requires a steady supply of 28 molybdenum for synthesis of the iron-molybdenum cofactor of nitrogenase. This nutrient 29 has to be provided by the host plant from the soil, crossing several symplastically 30 disconnected compartments through molybdate transporters, including members of the 31 MOT1 family. MtMOT1.2 is a Medicago truncatula MOT1 family member located in 32 the endodermal cells in roots and nodules. Immunolocalization of a tagged MtMOT1.2 33 indicates that it is associated to the plasma membrane and to intracellular membrane 34 systems, where it would be transporting molybdate towards the cytosol, as indicated in 35 yeast transport assays. Loss-of-function mot1.2-1 mutant showed reduced growth 36 compared to wild-type plants when nitrogen fixation was required, but not when nitrogen 37 was provided as nitrate. While no effect on molybdenum-dependent nitrate reductase 38 activity was observed, nitrogenase activity was severely affected, explaining the observed 39 difference of growth depending on nitrogen source. This phenotype was the result of 40 molybdate not reaching the nitrogen-fixing nodules, since genetic complementation with 41 a wild-type MtMOT1.2 gene or molybdate-fortification of the nutrient solution, both 42 restored wild-type levels of growth and nitrogenase activity. These results support a 43 model in which MtMOT1.2 would mediate molybdate delivery by the vasculature into 44 the nodules. 45 46
format artículo
topic_facet symbiotic nitrogen fixation, rhizobia, plant nutrition, legume
author Patricia Gil-Díez1, Manuel Tejada-Jiménez1,2, Javier León-Mediavilla1, Jiangqi Wen, 7 Kirankumar S. Mysore3, Juan Imperial1,4, Manuel González-Guerrero1,5
author_facet Patricia Gil-Díez1, Manuel Tejada-Jiménez1,2, Javier León-Mediavilla1, Jiangqi Wen, 7 Kirankumar S. Mysore3, Juan Imperial1,4, Manuel González-Guerrero1,5
author_sort Patricia Gil-Díez1, Manuel Tejada-Jiménez1,2, Javier León-Mediavilla1, Jiangqi Wen, 7 Kirankumar S. Mysore3, Juan Imperial1,4, Manuel González-Guerrero1,5
title MtMOT1.2 is responsible for molybdate supply to Medicago truncatula nodules
title_short MtMOT1.2 is responsible for molybdate supply to Medicago truncatula nodules
title_full MtMOT1.2 is responsible for molybdate supply to Medicago truncatula nodules
title_fullStr MtMOT1.2 is responsible for molybdate supply to Medicago truncatula nodules
title_full_unstemmed MtMOT1.2 is responsible for molybdate supply to Medicago truncatula nodules
title_sort mtmot1.2 is responsible for molybdate supply to medicago truncatula nodules
publishDate 2019-01
url http://hdl.handle.net/10261/205331
work_keys_str_mv AT patriciagildiez1manueltejadajimenez12javierleonmediavilla1jiangqiwen7kirankumarsmysore3juanimperial14manuelgonzalezguerrero15 mtmot12isresponsibleformolybdatesupplytomedicagotruncatulanodules
_version_ 1777663725722927104
spelling dig-ica-es-10261-2053312020-05-06T10:03:05Z MtMOT1.2 is responsible for molybdate supply to Medicago truncatula nodules Patricia Gil-Díez1, Manuel Tejada-Jiménez1,2, Javier León-Mediavilla1, Jiangqi Wen, 7 Kirankumar S. Mysore3, Juan Imperial1,4, Manuel González-Guerrero1,5 symbiotic nitrogen fixation, rhizobia, plant nutrition, legume ABSTRACT 27 Symbiotic nitrogen fixation in legume root nodules requires a steady supply of 28 molybdenum for synthesis of the iron-molybdenum cofactor of nitrogenase. This nutrient 29 has to be provided by the host plant from the soil, crossing several symplastically 30 disconnected compartments through molybdate transporters, including members of the 31 MOT1 family. MtMOT1.2 is a Medicago truncatula MOT1 family member located in 32 the endodermal cells in roots and nodules. Immunolocalization of a tagged MtMOT1.2 33 indicates that it is associated to the plasma membrane and to intracellular membrane 34 systems, where it would be transporting molybdate towards the cytosol, as indicated in 35 yeast transport assays. Loss-of-function mot1.2-1 mutant showed reduced growth 36 compared to wild-type plants when nitrogen fixation was required, but not when nitrogen 37 was provided as nitrate. While no effect on molybdenum-dependent nitrate reductase 38 activity was observed, nitrogenase activity was severely affected, explaining the observed 39 difference of growth depending on nitrogen source. This phenotype was the result of 40 molybdate not reaching the nitrogen-fixing nodules, since genetic complementation with 41 a wild-type MtMOT1.2 gene or molybdate-fortification of the nutrient solution, both 42 restored wild-type levels of growth and nitrogenase activity. These results support a 43 model in which MtMOT1.2 would mediate molybdate delivery by the vasculature into 44 the nodules. 45 46 19 molybdate delivery for nitrogen fixation is occurring at the 450 level of nodule vessels and 451 not in loading the root vasculature with Mo. Otherwise, an accumulation of Mo in mot1.2 452 roots would be expected as well as a decrease in shoots, and none was detected in either 453 (in this case, even slightly higher levels were detected, which might correspond to surplus 454 Mo being delivered to the shoots). 455 In summary, MtMOT1.2 would position itself between molybdate root uptake 456 transporter, likely MtMOT1.1 as the closest LjMOT1 orthologue, and the nodule apoplast 457 molybdate uptake protein MtMOT1.3 (Fig. 6). MtMOT1.2 would facilitate the transfer 458 of this nutrient into endodermal cells mediating the sink-to-source molybdate trafficking, 459 which would be controlled by mass-effects to ensure that it reaches its destination. 460 However, a critical point remains to be solved, which is the identity of the proteins 461 mediating molybdate efflux from the cytosol to the symbiosome. Whether these are 462 sulfate transporters, or whether a novel family of Mo transporters with a direction of 463 transport opposite to MOT1 proteins, remains to be unveiled. 464 465 ACKNOWLEDGEMENTS 466 This research was funded by a European Research Council Starting Grant (ERC- 467 2013-StG-335284) and a Spanish Ministry of Economy and Competitiveness grant 468 (AGL2015-65866-P) to M.G-G. Development of the M. truncatula Tnt1 mutant 469 population was, in part, funded by the National Science Foundation, USA (DBI-0703285 470 & IOS-1127155) to K.S.M. Yeast transport assays were partially funded by the Plan 471 Propio de la Universidad de Córdoba (to M.T-J) and MINECO (BFU2015-70649-P). The 472 authors would like to thank Dr. Emilio Fernández and Dr. Aurora Galván (Universidad 473 de Córdoba) for their help with the yeast transport assays, as well as to members of 20 Laboratory 281 at Centro de Biotecnología y Genómica de 474 Plantas (UPM-INIA) for their 475 support and feed-back in preparing this manuscript, Peer reviewed 2020-03-26T12:36:36Z 2020-03-26T12:36:36Z 2019-01 artículo http://purl.org/coar/resource_type/c_6501 Plant Cell and Environment, 42(1) 310-320 http://hdl.handle.net/10261/205331 10.1111/pce.13388 Postprint Sí open

Similar Items