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Gavrin A, Loughlin PC, Brear E, Griffith OW, Bedon F, Suter Grotemeyer M, Escudero V, Reguera M, Qu Y, Mohd-Noor SN, Chen C, Osorio MB, Rentsch D, González-Guerrero M, Day DA, Smith PMC. Soybean Yellow Stripe-like 7 is a symbiosome membrane peptide transporter important for nitrogen fixation. PLANT PHYSIOLOGY 2021; 186:581-598. [PMID: 33619553 PMCID: PMC8154080 DOI: 10.1093/plphys/kiab044] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 01/21/2021] [Indexed: 05/05/2023]
Abstract
Legumes form a symbiosis with rhizobia that convert atmospheric nitrogen (N2) to ammonia and provide it to the plant in return for a carbon and nutrient supply. Nodules, developed as part of the symbiosis, harbor rhizobia that are enclosed in a plant-derived symbiosome membrane (SM) to form an organelle-like structure called the symbiosome. In mature nodules exchanges between the symbionts occur across the SM. Here we characterize Yellow Stripe-like 7 (GmYSL7), a Yellow stripe-like family member localized on the SM in soybean (Glycine max) nodules. It is expressed specifically in infected cells with expression peaking soon after nitrogenase becomes active. Unlike most YSL family members, GmYSL7 does not transport metals complexed with phytosiderophores. Rather, it transports oligopeptides of between four and 12 amino acids. Silencing GmYSL7 reduces nitrogenase activity and blocks infected cell development so that symbiosomes contain only a single bacteroid. This indicates the substrate of YSL7 is required for proper nodule development, either by promoting symbiosome development directly or by preventing inhibition of development by the plant. RNAseq of nodules where GmYSL7 was silenced suggests that the plant initiates a defense response against rhizobia with genes encoding proteins involved in amino acid export downregulated and some transcripts associated with metal homeostasis altered. These changes may result from the decrease in nitrogen fixation upon GmYSL7 silencing and suggest that the peptide(s) transported by GmYSL7 monitor the functional state of the bacteroids and regulate nodule metabolism and transport processes accordingly. Further work to identify the physiological substrate for GmYSL7 will allow clarification of this role.
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Affiliation(s)
- Aleksandr Gavrin
- Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, UK
| | - Patrick C Loughlin
- School of Life and Environmental Science, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Ella Brear
- School of Life and Environmental Science, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Oliver W Griffith
- Department of Biological Sciences, Macquarie University, Macquarie Park, NSW 2109, Australia
| | - Frank Bedon
- School of Life Sciences, La Trobe University, Bundoora, Victoria 3083, Australia
| | | | - Viviana Escudero
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA). Universidad Politécnica de Madrid, Campus de Montegancedo, Crta, 28223 Pozuelo de Alarcón (Madrid), Spain
| | - Maria Reguera
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA). Universidad Politécnica de Madrid, Campus de Montegancedo, Crta, 28223 Pozuelo de Alarcón (Madrid), Spain
| | - Yihan Qu
- School of Life and Environmental Science, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Siti N Mohd-Noor
- School of Life and Environmental Science, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Chi Chen
- School of Life and Environmental Science, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Marina Borges Osorio
- School of Life Sciences, La Trobe University, Bundoora, Victoria 3083, Australia
| | - Doris Rentsch
- IPS, Molecular Plant Physiology, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland
| | - Manuel González-Guerrero
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA). Universidad Politécnica de Madrid, Campus de Montegancedo, Crta, 28223 Pozuelo de Alarcón (Madrid), Spain
| | - David A Day
- College of Science and Engineering, Flinders University, Bedford Park, Adelaide, SA, Australia
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Day DA, Smith PMC. Iron Transport across Symbiotic Membranes of Nitrogen-Fixing Legumes. Int J Mol Sci 2021; 22:E432. [PMID: 33406726 PMCID: PMC7794740 DOI: 10.3390/ijms22010432] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 12/31/2020] [Accepted: 12/31/2020] [Indexed: 12/30/2022] Open
Abstract
Iron is an essential nutrient for the legume-rhizobia symbiosis and nitrogen-fixing bacteroids within root nodules of legumes have a very high demand for the metal. Within the infected cells of nodules, the bacteroids are surrounded by a plant membrane to form an organelle-like structure called the symbiosome. In this review, we focus on how iron is transported across the symbiosome membrane and accessed by the bacteroids.
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Affiliation(s)
- David A. Day
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
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