1
|
Li Y, Liu Q, Zhang DX, Zhang ZY, Xu A, Jiang YL, Chen ZC. Metal nutrition and transport in the process of symbiotic nitrogen fixation. PLANT COMMUNICATIONS 2024; 5:100829. [PMID: 38303509 PMCID: PMC11009365 DOI: 10.1016/j.xplc.2024.100829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 01/14/2024] [Accepted: 01/26/2024] [Indexed: 02/03/2024]
Abstract
Symbiotic nitrogen fixation (SNF) facilitated by the interaction between legumes and rhizobia is a well-documented and eco-friendly alternative to chemical nitrogen fertilizers. Host plants obtain fixed nitrogen from rhizobia by providing carbon and mineral nutrients. These mineral nutrients, which are mostly in the form of metal ions, are implicated in various stages of the SNF process. This review describes the functional roles played by metal ions in nodule formation and nitrogen fixation and specifically addresses their transport mechanisms and associated transporters within root nodules. Future research directions and potential strategies for enhancing SNF efficiency are also discussed.
Collapse
Affiliation(s)
- Yuan Li
- Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Qian Liu
- Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Dan-Xun Zhang
- Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhuo-Yan Zhang
- Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Ao Xu
- Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yuan-Long Jiang
- Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhi-Chang Chen
- Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| |
Collapse
|
2
|
González-Guerrero M, Navarro-Gómez C, Rosa-Núñez E, Echávarri-Erasun C, Imperial J, Escudero V. Forging a symbiosis: transition metal delivery in symbiotic nitrogen fixation. THE NEW PHYTOLOGIST 2023; 239:2113-2125. [PMID: 37340839 DOI: 10.1111/nph.19098] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Accepted: 06/08/2023] [Indexed: 06/22/2023]
Abstract
Symbiotic nitrogen fixation carried out by the interaction between legumes and rhizobia is the main source of nitrogen in natural ecosystems and in sustainable agriculture. For the symbiosis to be viable, nutrient exchange between the partners is essential. Transition metals are among the nutrients delivered to the nitrogen-fixing bacteria within the legume root nodule cells. These elements are used as cofactors for many of the enzymes controlling nodule development and function, including nitrogenase, the only known enzyme able to convert N2 into NH3 . In this review, we discuss the current knowledge on how iron, zinc, copper, and molybdenum reach the nodules, how they are delivered to nodule cells, and how they are transferred to nitrogen-fixing bacteria within.
Collapse
Affiliation(s)
- Manuel González-Guerrero
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA/CSIC), Campus de Montegancedo UPM, 28223, Pozuelo de Alarcón, Spain
- Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, 28040, Madrid, Spain
| | - Cristina Navarro-Gómez
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA/CSIC), Campus de Montegancedo UPM, 28223, Pozuelo de Alarcón, Spain
| | - Elena Rosa-Núñez
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA/CSIC), Campus de Montegancedo UPM, 28223, Pozuelo de Alarcón, Spain
| | - Carlos Echávarri-Erasun
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA/CSIC), Campus de Montegancedo UPM, 28223, Pozuelo de Alarcón, Spain
- Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, 28040, Madrid, Spain
| | - Juan Imperial
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA/CSIC), Campus de Montegancedo UPM, 28223, Pozuelo de Alarcón, Spain
| | - Viviana Escudero
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA/CSIC), Campus de Montegancedo UPM, 28223, Pozuelo de Alarcón, Spain
| |
Collapse
|
3
|
Liu Y, Xiong Z, Wu W, Ling HQ, Kong D. Iron in the Symbiosis of Plants and Microorganisms. PLANTS (BASEL, SWITZERLAND) 2023; 12:1958. [PMID: 37653875 PMCID: PMC10223382 DOI: 10.3390/plants12101958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/08/2023] [Accepted: 05/08/2023] [Indexed: 09/02/2023]
Abstract
Iron is an essential element for most organisms. Both plants and microorganisms have developed different mechanisms for iron uptake, transport and storage. In the symbiosis systems, such as rhizobia-legume symbiosis and arbuscular mycorrhizal (AM) symbiosis, maintaining iron homeostasis to meet the requirements for the interaction between the host plants and the symbiotic microbes is a new challenge. This intriguing topic has drawn the attention of many botanists and microbiologists, and many discoveries have been achieved so far. In this review, we discuss the current progress on iron uptake and transport in the nodules and iron homeostasis in rhizobia-legume symbiosis. The discoveries with regard to iron uptake in AM fungi, iron uptake regulation in AM plants and interactions between iron and other nutrient elements during AM symbiosis are also summarized. At the end of this review, we propose prospects for future studies in this fascinating research area.
Collapse
Affiliation(s)
- Yi Liu
- Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang 332900, China; (Y.L.)
| | - Zimo Xiong
- Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang 332900, China; (Y.L.)
| | - Weifeng Wu
- Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang 332900, China; (Y.L.)
| | - Hong-Qing Ling
- Hainan Yazhou Bay Seed Laboratory, Sanya 572024, China;
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Danyu Kong
- Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang 332900, China; (Y.L.)
| |
Collapse
|
4
|
Huertas R, Karpinska B, Ngala S, Mkandawire B, Maling'a J, Wajenkeche E, Kimani PM, Boesch C, Stewart D, Hancock RD, Foyer CH. Biofortification of common bean ( Phaseolus vulgaris L.) with iron and zinc: Achievements and challenges. Food Energy Secur 2023; 12:e406. [PMID: 38440694 PMCID: PMC10909572 DOI: 10.1002/fes3.406] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 06/01/2022] [Accepted: 06/08/2022] [Indexed: 03/06/2024] Open
Abstract
Micronutrient deficiencies (hidden hunger), particularly in iron (Fe) and zinc (Zn), remain one of the most serious public health challenges, affecting more than three billion people globally. A number of strategies are used to ameliorate the problem of micronutrient deficiencies and to improve the nutritional profile of food products. These include (i) dietary diversification, (ii) industrial food fortification and supplements, (iii) agronomic approaches including soil mineral fertilisation, bioinoculants and crop rotations, and (iv) biofortification through the implementation of biotechnology including gene editing and plant breeding. These efforts must consider the dietary patterns and culinary preferences of the consumer and stakeholder acceptance of new biofortified varieties. Deficiencies in Zn and Fe are often linked to the poor nutritional status of agricultural soils, resulting in low amounts and/or poor availability of these nutrients in staple food crops such as common bean. This review describes the genes and processes associated with Fe and Zn accumulation in common bean, a significant food source in Africa that plays an important role in nutritional security. We discuss the conventional plant breeding, transgenic and gene editing approaches that are being deployed to improve Fe and Zn accumulation in beans. We also consider the requirements of successful bean biofortification programmes, highlighting gaps in current knowledge, possible solutions and future perspectives.
Collapse
Affiliation(s)
- Raul Huertas
- Environmental and Biochemical SciencesThe James Hutton InstituteDundeeUK
| | - Barbara Karpinska
- School of Biosciences, College of Life and Environmental SciencesUniversity of BirminghamEdgbastonUK
| | - Sophia Ngala
- Department of Plant Science and Crop Protection, College of Agriculture and Veterinary SciencesUniversity of NairobiNairobiKenya
| | - Bertha Mkandawire
- The Food, Agriculture and Natural Resources Policy Analysis Network (FANRPAN)PretoriaSouth Africa
| | - Joyce Maling'a
- Kenya Agriculture and Livestock Research Organization (KALRO)Food Crops Research InstituteKitaleKenya
| | - Elizabeth Wajenkeche
- Kenya Agriculture and Livestock Research Organization (KALRO)Food Crops Research InstituteKitaleKenya
| | - Paul M. Kimani
- Department of Plant Science and Crop Protection, College of Agriculture and Veterinary SciencesUniversity of NairobiNairobiKenya
| | | | - Derek Stewart
- Environmental and Biochemical SciencesThe James Hutton InstituteDundeeUK
- School of Engineering and Physical SciencesHeriot‐Watt UniversityEdinburghUK
| | | | - Christine H. Foyer
- School of Biosciences, College of Life and Environmental SciencesUniversity of BirminghamEdgbastonUK
| |
Collapse
|
5
|
Helaoui S, Boughattas I, El Kribi-Boukhris S, Mkhinini M, Alphonse V, Livet A, Bousserrhine N, Banni M. Assessing the effects of nickel on, e.g., Medicago sativa L. nodules using multidisciplinary approach. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:77386-77400. [PMID: 35672641 DOI: 10.1007/s11356-022-21311-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 06/01/2022] [Indexed: 06/15/2023]
Abstract
Industrial wastes and fertilizers can introduce excessive levels of nickel (Ni) into the environment, potentially causing threats to plants, animals, as well as human beings. However, the number of studies on the effects of Ni toxicity on nodules is fairly limited. To address this issue, the effects of increasing Ni concentration on alfalfa nodules were assessed at chemical, biochemical, and transcriptomic levels. For this purpose, plants were grown in soils supplied with Ni (control, 0 mg/kg; C1, 50 mg/kg; C2, 150 mg/kg; C3, 250 mg/kg; and C4, 500 mg/kg) for 90 days. Ni loads in leaves, roots, and nodules were monitored after the exposure period. A set of biochemical biomarkers of oxidative stress was determined in nodules including antioxidants and metal homeostasis as well as lipid peroxidation. Gene expression levels of the main targets involved in oxidative stress and metal homeostasis were assessed. Our data indicated a high concentration of Ni in leaves, roots, and nodules where values reached 25.64 ± 3.04 mg/kg, 83.23 ± 5.16 mg/kg, and 125.71 ± 4.53 mg/kg in dry weight, respectively. Moreover, a significant increase in nodule biomass was observed in plants exposed to C4 in comparison to control treatment and percentage increased by 63%. Then, lipid peroxidation increased with a rate of 95% in nodules exposed to C4. Enzymatic activities were enhanced remarkably, suggesting the occurrence of oxidative stress, with increased superoxide dismutase (SOD), glutathione reductase (GR), and ascorbate peroxidase (APX). Our results showed also a significant upregulation of SOD, GR and APX genes in nodules. Nodule homoglutathione (HGSH) levels increased with the different Ni concentrations, with a remarkable decrease of glutathione S-transferase (GST) activity and glutathione (GSH) content for the highest Ni concentration with 43% and 52% reduction, respectively. The phytochelatin (PC) and metallothionein (MT) concentrations increased in nodules, which implied the triggering of a cellular protection mechanism for coping with Ni toxicity. The results suggested that Ni promotes a drastic oxidative stress in alfalfa nodules, yet the expression of MT and PC to reduce Ni toxicity could be used as Ni stress bioindicators. Our findings provide new insights into the central role of alfalfa nodules in limiting the harmful effects of soil pollution. Therefore, nodules co-expressing antioxidant enzymes may have high phytoremediation potential.
Collapse
Affiliation(s)
- Sondes Helaoui
- Laboratory of Biochemistry and Environmental Toxicology, Higher Institute of Agronomy, University of Sousse, Sousse, Tunisia
| | - Iteb Boughattas
- Laboratory of Biochemistry and Environmental Toxicology, Higher Institute of Agronomy, University of Sousse, Sousse, Tunisia.
| | - Sameh El Kribi-Boukhris
- Laboratory of Biochemistry and Environmental Toxicology, Higher Institute of Agronomy, University of Sousse, Sousse, Tunisia
| | - Marouane Mkhinini
- Laboratory of Biochemistry and Environmental Toxicology, Higher Institute of Agronomy, University of Sousse, Sousse, Tunisia
| | - Vanessa Alphonse
- Laboratory Water, Environment and Urban Systems, Faculty of Science and Technology, University Paris-Est Créteil, Créteil Cedex, France
| | - Alexandre Livet
- Laboratory Water, Environment and Urban Systems, Faculty of Science and Technology, University Paris-Est Créteil, Créteil Cedex, France
| | - Noureddine Bousserrhine
- Laboratory Water, Environment and Urban Systems, Faculty of Science and Technology, University Paris-Est Créteil, Créteil Cedex, France
| | - Mohamed Banni
- Laboratory of Biochemistry and Environmental Toxicology, Higher Institute of Agronomy, University of Sousse, Sousse, Tunisia
- Higher Institute of Biotechnologie of Monastir, University of Monastir, Monastir, Tunisia
| |
Collapse
|
6
|
Kallala N, M'sehli W, Jelali K, Kais Z, Mhadhbi H. Inoculation with Efficient Nitrogen Fixing and Indoleacetic Acid Producing Bacterial Microsymbiont Enhance Tolerance of the Model Legume Medicago truncatula to Iron Deficiency. BIOMED RESEARCH INTERNATIONAL 2018; 2018:9134716. [PMID: 30406145 PMCID: PMC6201330 DOI: 10.1155/2018/9134716] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 09/25/2018] [Indexed: 12/23/2022]
Abstract
The aim of this study was to assess the effect of symbiotic bacteria inoculation on the response of Medicago truncatula genotypes to iron deficiency. The present work was conducted on three Medicago truncatula genotypes: A17, TN8.20, and TN1.11. Three treatments were performed: control (C), direct Fe deficiency (DD), and induced Fe deficiency by bicarbonate (ID). Plants were nitrogen-fertilized (T) or inoculated with two bacterial strains: Sinorhizobium meliloti TII7 and Sinorhizobium medicae SII4. Biometric, physiological, and biochemical parameters were analyzed. Iron deficiency had a significant lowering effect on plant biomass and chlorophyll content in all Medicago truncatula genotypes. TN1.11 showed the highest lipid peroxidation and leakage of electrolyte under iron deficiency conditions, which suggest that TN1.11 was more affected than A17 and TN8.20 by Fe starvation. Iron deficiency affected symbiotic performance indices of all Medicago truncatula genotypes inoculated with both Sinorhizobium strains, mainly nodules number and biomass as well as nitrogen-fixing capacity. Nevertheless, inoculation with Sinorhizobium strains mitigates the negative effect of Fe deficiency on plant growth and oxidative stress compared to nitrogen-fertilized plants. The highest auxin producing strain, TII7, preserves relatively high growth and root biomass and length when inoculated to TN8.20 and A17. On the other hand, both TII7 and SII4 strains improve the performance of sensitive genotype TN1.11 through reduction of the negative effect of iron deficiency on chlorophyll and plant Fe content. The bacterial inoculation improved Fe-deficient plant response to oxidative stress via the induction of the activities of antioxidant enzymes.
Collapse
Affiliation(s)
- Nadia Kallala
- Laboratory of Legumes, Center of Biotechnology of Borj-Cedria (CBBC), Hammam-Lif, Tunisia
- Faculty of Science, University of Tunis El Manar, 2092 Tunis, Tunisia
| | - Wissal M'sehli
- Laboratory of Legumes, Center of Biotechnology of Borj-Cedria (CBBC), Hammam-Lif, Tunisia
| | - Karima Jelali
- Laboratory of Legumes, Center of Biotechnology of Borj-Cedria (CBBC), Hammam-Lif, Tunisia
- Faculty of Science, University of Tunis El Manar, 2092 Tunis, Tunisia
| | - Zribi Kais
- Laboratory of Legumes, Center of Biotechnology of Borj-Cedria (CBBC), Hammam-Lif, Tunisia
| | - Haythem Mhadhbi
- Laboratory of Legumes, Center of Biotechnology of Borj-Cedria (CBBC), Hammam-Lif, Tunisia
| |
Collapse
|
7
|
Adnane B, Mainassara ZA, Mohamed F, Mohamed L, Jean-Jacques D, Rim MT, Georg C. Physiological and Molecular Aspects of Tolerance to Environmental Constraints in Grain and Forage Legumes. Int J Mol Sci 2015; 16:18976-9008. [PMID: 26287163 PMCID: PMC4581282 DOI: 10.3390/ijms160818976] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Revised: 07/09/2015] [Accepted: 08/05/2015] [Indexed: 12/04/2022] Open
Abstract
Despite the agronomical and environmental advantages of the cultivation of legumes, their production is limited by various environmental constraints such as water or nutrient limitation, frost or heat stress and soil salinity, which may be the result of pedoclimatic conditions, intensive use of agricultural lands, decline in soil fertility and environmental degradation. The development of more sustainable agroecosystems that are resilient to environmental constraints will therefore require better understanding of the key mechanisms underlying plant tolerance to abiotic constraints. This review provides highlights of legume tolerance to abiotic constraints with a focus on soil nutrient deficiencies, drought, and salinity. More specifically, recent advances in the physiological and molecular levels of the adaptation of grain and forage legumes to abiotic constraints are discussed. Such adaptation involves complex multigene controlled-traits which also involve multiple sub-traits that are likely regulated under the control of a number of candidate genes. This multi-genetic control of tolerance traits might also be multifunctional, with extended action in response to a number of abiotic constraints. Thus, concrete efforts are required to breed for multifunctional candidate genes in order to boost plant stability under various abiotic constraints.
Collapse
Affiliation(s)
- Bargaz Adnane
- Department of Biosystems and Technology, Swedish University of Agricultural Sciences, Box 103, SE-23053 Alnarp, Sweden.
| | - Zaman-Allah Mainassara
- International Maize and Wheat Improvement Center (CIMMYT), Southern Africa Regional Office, MP163 Harare, Zimbabwe.
| | - Farissi Mohamed
- Polyvalent Laboratory for Research & Development, Polydisciplinary Faculty, Sultan Moulay Sliman University, 23000 Beni-Mellal, Morocco.
| | - Lazali Mohamed
- Faculté des Sciences de la Nature et de la Vie & des Sciences de la Terre, Université de Khemis Miliana, 44225 Ain Defla, Algeria.
| | - Drevon Jean-Jacques
- Unité mixte de recherche, Écologie Fonctionnelle & Biogéochimie des Sols et Agroécosystèmes, Institut National de la Recherche Agronomique, 34060 Montpellier, France.
| | - Maougal T Rim
- Laboratoire de génétique Biochimie et biotechnologies végétales Faculté des Sciences de la Nature et de la Vie, Université des frères Mentouri, 25017 Constantine, Algeria.
| | - Carlsson Georg
- Department of Biosystems and Technology, Swedish University of Agricultural Sciences, Box 103, SE-23053 Alnarp, Sweden.
| |
Collapse
|
8
|
Slatni T, Ben Salah I, Kouas S, Abdelly C. The role of nodules in the tolerance of common bean to iron deficiency. JOURNAL OF PLANT RESEARCH 2014; 127:455-465. [PMID: 24718900 DOI: 10.1007/s10265-014-0632-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 02/11/2014] [Indexed: 06/03/2023]
Abstract
Iron is vital for the establishment and function of symbiotic root nodules of legumes. Although abundant in the environment, Fe is often a limiting nutrient for plant growth due to its low solubility and availability in some soils. We have studied the mechanism of iron uptake in the root nodules of common bean to evaluate the role of nodules in physiological responses to iron deficiency. Based on experiments using full or partial submergence of nodulated roots in the nutrient solution, our results show that the nodules were affected only slightly under iron deficiency, especially when the nodules were submerged in nutrient solution in the tolerant cultivar. In addition, fully submerged root nodules showed enhanced acidification of the nutrient solution and showed higher ferric chelate reductase activity than that of partially submerged roots in plants cultivated under Fe deficiency. The main results obtained in this work suggest that in addition to preferential Fe allocation from the root system to the nodules, this symbiotic organ probably develops some mechanisms to respond to iron deficiency. These mechanisms were implied especially in nodule Fe absorption efficiency and in the ability of this organ to take up Fe directly from the medium.
Collapse
Affiliation(s)
- Tarek Slatni
- Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie, Technopole de Borj Cedria, BP 901, 2050, Hammam Lif, Tunisia,
| | | | | | | |
Collapse
|
9
|
González-Guerrero M, Matthiadis A, Sáez Á, Long TA. Fixating on metals: new insights into the role of metals in nodulation and symbiotic nitrogen fixation. FRONTIERS IN PLANT SCIENCE 2014; 5:45. [PMID: 24592271 PMCID: PMC3923141 DOI: 10.3389/fpls.2014.00045] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Accepted: 01/29/2014] [Indexed: 05/05/2023]
Abstract
Symbiotic nitrogen fixation is one of the most promising and immediate alternatives to the overuse of polluting nitrogen fertilizers for improving plant nutrition. At the core of this process are a number of metalloproteins that catalyze and provide energy for the conversion of atmospheric nitrogen to ammonia, eliminate free radicals produced by this process, and create the microaerobic conditions required by these reactions. In legumes, metal cofactors are provided to endosymbiotic rhizobia within root nodule cortical cells. However, low metal bioavailability is prevalent in most soils types, resulting in widespread plant metal deficiency and decreased nitrogen fixation capabilities. As a result, renewed efforts have been undertaken to identify the mechanisms governing metal delivery from soil to the rhizobia, and to determine how metals are used in the nodule and how they are recycled once the nodule is no longer functional. This effort is being aided by improved legume molecular biology tools (genome projects, mutant collections, and transformation methods), in addition to state-of-the-art metal visualization systems.
Collapse
Affiliation(s)
| | - Anna Matthiadis
- Department of Plant and Microbial Biology, North Carolina State UniversityRaleigh, NC, USA
| | - Áez;ngela Sáez
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de MadridMadrid, Spain
| | - Terri A. Long
- Department of Plant and Microbial Biology, North Carolina State UniversityRaleigh, NC, USA
| |
Collapse
|
10
|
Jin CW, Ye YQ, Zheng SJ. An underground tale: contribution of microbial activity to plant iron acquisition via ecological processes. ANNALS OF BOTANY 2014; 113:7-18. [PMID: 24265348 PMCID: PMC3864720 DOI: 10.1093/aob/mct249] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 09/06/2013] [Indexed: 05/19/2023]
Abstract
BACKGROUND Iron (Fe) deficiency in crops is a worldwide agricultural problem. Plants have evolved several strategies to enhance Fe acquisition, but increasing evidence has shown that the intrinsic plant-based strategies alone are insufficient to avoid Fe deficiency in Fe-limited soils. Soil micro-organisms also play a critical role in plant Fe acquisition; however, the mechanisms behind their promotion of Fe acquisition remain largely unknown. SCOPE This review focuses on the possible mechanisms underlying the promotion of plant Fe acquisition by soil micro-organisms. CONCLUSIONS Fe-deficiency-induced root exudates alter the microbial community in the rhizosphere by modifying the physicochemical properties of soil, and/or by their antimicrobial and/or growth-promoting effects. The altered microbial community may in turn benefit plant Fe acquisition via production of siderophores and protons, both of which improve Fe bioavailability in soil, and via hormone generation that triggers the enhancement of Fe uptake capacity in plants. In addition, symbiotic interactions between micro-organisms and host plants could also enhance plant Fe acquisition, possibly including: rhizobium nodulation enhancing plant Fe uptake capacity and mycorrhizal fungal infection enhancing root length and the nutrient acquisition area of the root system, as well as increasing the production of Fe(3+) chelators and protons.
Collapse
Affiliation(s)
- Chong Wei Jin
- College of Natural Resources and Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Yi Quan Ye
- College of Natural Resources and Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Shao Jian Zheng
- State Key Laboratory of Plant Biochemistry and Physiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| |
Collapse
|
11
|
Brear EM, Day DA, Smith PMC. Iron: an essential micronutrient for the legume-rhizobium symbiosis. FRONTIERS IN PLANT SCIENCE 2013; 4:359. [PMID: 24062758 PMCID: PMC3772312 DOI: 10.3389/fpls.2013.00359] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 08/26/2013] [Indexed: 05/19/2023]
Abstract
Legumes, which develop a symbiosis with nitrogen-fixing bacteria, have an increased demand for iron. Iron is required for the synthesis of iron-containing proteins in the host, including the highly abundant leghemoglobin, and in bacteroids for nitrogenase and cytochromes of the electron transport chain. Deficiencies in iron can affect initiation and development of the nodule. Within root cells, iron is chelated with organic acids such as citrate and nicotianamine and distributed to other parts of the plant. Transport to the nitrogen-fixing bacteroids in infected cells of nodules is more complicated. Formation of the symbiosis results in bacteroids internalized within root cortical cells of the legume where they are surrounded by a plant-derived membrane termed the symbiosome membrane (SM). This membrane forms an interface that regulates nutrient supply to the bacteroid. Consequently, iron must cross this membrane before being supplied to the bacteroid. Iron is transported across the SM as both ferric and ferrous iron. However, uptake of Fe(II) by both the symbiosome and bacteroid is faster than Fe(III) uptake. Members of more than one protein family may be responsible for Fe(II) transport across the SM. The only Fe(II) transporter in nodules characterized to date is GmDMT1 (Glycine max divalent metal transporter 1), which is located on the SM in soybean. Like the root plasma membrane, the SM has ferric iron reductase activity. The protein responsible has not been identified but is predicted to reduce ferric iron accumulated in the symbiosome space prior to uptake by the bacteroid. With the recent publication of a number of legume genomes including Medicago truncatula and G. max, a large number of additional candidate transport proteins have been identified. Members of the NRAMP (natural resistance-associated macrophage protein), YSL (yellow stripe-like), VIT (vacuolar iron transporter), and ZIP (Zrt-, Irt-like protein) transport families show enhanced expression in nodules and are expected to play a role in the transport of iron and other metals across symbiotic membranes.
Collapse
Affiliation(s)
- Ella M. Brear
- School of Biological Sciences, The University of SydneySydney, NSW, Australia
| | - David A. Day
- School of Biological Sciences, Flinders UniversityBedford Park, Adelaide, SA, Australia
| | | |
Collapse
|