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Escudero V, Fuenzalida M, Rezende EL, González-Guerrero M, Roschzttardtz H. Perspectives on embryo maturation and seed quality in a global climate change scenario. J Exp Bot 2024:erae154. [PMID: 38597771 DOI: 10.1093/jxb/erae154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Indexed: 04/11/2024]
Abstract
Global climate change has already brought noticeable alterations to multiple regions of our planet. Several important steps of plant growth and development, such as embryogenesis, can be affected by environmental changes. For instance, these changes would affect how stored nutrients are used during early stages of seed germination as it transitions from a heterotrophic to autotrophic metabolism, a critical period for the seedling's survival. In this perspective, we provide a brief description of relevant processes that occur during embryo maturation and account for nutrient accumulation, which are sensitive to environmental change. As examples of the effects associated with climate change are increased CO2 levels and changes in temperature. During seed development, most of the nutrients stored in the seed are accumulated during the seed maturation stage. These nutrients include, depending on the plant species, carbohydrates, lipids and proteins. Regarding micronutrients, it has also been established that iron, a key micronutrient for various electron transfer processes in plant cells, accumulates during embryo maturation. Several articles have been published indicating that climate change can affect the quality of the seed, in terms of total nutritional content, but also, it may affect seed production. Here we discuss the potential effects of temperature and CO2 increase from an embryo autonomous point of view, in an attempt to separate the maternal effects from embryonic effects.
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Affiliation(s)
- Viviana Escudero
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Universidad Politécnica de Madrid, Spain
| | - Marlene Fuenzalida
- Pontificia Universidad Católica de Chile, Facultad de Ciencias Biológicas, Santiago, Chile
| | - Enrico L Rezende
- Pontificia Universidad Católica de Chile, Facultad de Ciencias Biológicas, Santiago, Chile
- Center for Applied Ecology and Sustainability (CAPES), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Manuel González-Guerrero
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Universidad Politécnica de Madrid, Spain
- Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas. Universidad Politécnica de Madrid, Spain
| | - Hannetz Roschzttardtz
- Pontificia Universidad Católica de Chile, Facultad de Ciencias Biológicas, Santiago, Chile
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2
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Fuenzalida M, Gómez MI, Ferrada E, Díaz C, Escudero V, González-Guerrero M, Jordana X, Roschzttardtz H. Using an embryo specific promoter to modify iron distribution pattern in Arabidopsis. Plant Sci 2024; 339:111931. [PMID: 38030036 DOI: 10.1016/j.plantsci.2023.111931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 12/01/2023]
Abstract
Iron is an essential micronutrient for life. During the development of the seed, iron accumulates during embryo maturation. In Arabidopsis thaliana, iron mainly accumulates in the vacuoles of only one cell type, the cell layer that surrounds provasculature in hypocotyl and cotyledons. Iron accumulation pattern in Arabidopsis is an exception in plant phylogeny, most part of the dicot embryos accumulate iron in several cell layers including cortex and, in some cases, even in protodermis. It remains unknown how does iron reach the internal cell layers of the embryo, and in particular, the molecular mechanisms responsible of this process. Here, we use transgenic approaches to modify the iron accumulation pattern in an Arabidopsis model. Using the SDH2-3 embryo-specific promoter, we were able to express VIT1 ectopically in both a wild type background and a mutant vit1 background lacking expression of this vacuolar iron transporter. These manipulations modify the iron distribution pattern in Arabidopsis from one cell layer to several cell layers, including protodermis, cortex cells, and the endodermis. Interestingly, total seed iron content was not modified compared with the wild type, suggesting that iron distribution in embryos is not involved in the control of the total iron amount accumulated in seeds. This experimental model can be used to study the processes involved in iron distribution patterning during embryo maturation and its evolution in dicot plants.
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Affiliation(s)
- Marlene Fuenzalida
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Chile
| | - María Isabel Gómez
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Chile
| | - Evandro Ferrada
- CeMM-Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Cristóbal Díaz
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Chile
| | - Viviana Escudero
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Universidad Politécnica de Madrid, Spain
| | - Manuel González-Guerrero
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Universidad Politécnica de Madrid, Spain; Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Spain
| | - Xavier Jordana
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Chile
| | - Hannetz Roschzttardtz
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Chile.
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3
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Roschzttardtz H, Gomez-Casati D, Dubos C, Quintana J. Editorial: Metallic micronutrient homeostasis in plants, volume II. Front Plant Sci 2023; 14:1329190. [PMID: 38107009 PMCID: PMC10722403 DOI: 10.3389/fpls.2023.1329190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Accepted: 11/24/2023] [Indexed: 12/19/2023]
Affiliation(s)
- Hannetz Roschzttardtz
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Diego Gomez-Casati
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Rosario, Argentina
| | - Christian Dubos
- Institut des Sciences des Plantes de Montpellier (IPSiM), University Montpellier, CNRS, INRAE, Montpellier, France
| | - Julia Quintana
- Center for Plant Biotechnology and Genomics, Universidad Politécnica de Madrid, Madrid, Spain
- Department of Biology and Geology, Physics and Inorganic Chemistry, Universidad Rey Juan Carlos, Madrid, Spain
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4
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Vargas J, Gómez I, Vidal EA, Lee CP, Millar AH, Jordana X, Roschzttardtz H. Growth Developmental Defects of Mitochondrial Iron Transporter 1 and 2 Mutants in Arabidopsis in Iron Sufficient Conditions. Plants (Basel) 2023; 12:1176. [PMID: 36904036 PMCID: PMC10007191 DOI: 10.3390/plants12051176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 01/25/2023] [Accepted: 02/22/2023] [Indexed: 06/18/2023]
Abstract
Iron is the most abundant micronutrient in plant mitochondria, and it has a crucial role in biochemical reactions involving electron transfer. It has been described in Oryza sativa that Mitochondrial Iron Transporter (MIT) is an essential gene and that knockdown mutant rice plants have a decreased amount of iron in their mitochondria, strongly suggesting that OsMIT is involved in mitochondrial iron uptake. In Arabidopsis thaliana, two genes encode MIT homologues. In this study, we analyzed different AtMIT1 and AtMIT2 mutant alleles, and no phenotypic defects were observed in individual mutant plants grown in normal conditions, confirming that neither AtMIT1 nor AtMIT2 are individually essential. When we generated crosses between the Atmit1 and Atmit2 alleles, we were able to isolate homozygous double mutant plants. Interestingly, homozygous double mutant plants were obtained only when mutant alleles of Atmit2 with the T-DNA insertion in the intron region were used for crossings, and in these cases, a correctly spliced AtMIT2 mRNA was generated, although at a low level. Atmit1 Atmit2 double homozygous mutant plants, knockout for AtMIT1 and knockdown for AtMIT2, were grown and characterized in iron-sufficient conditions. Pleiotropic developmental defects were observed, including abnormal seeds, an increased number of cotyledons, a slow growth rate, pinoid stems, defects in flower structures, and reduced seed set. A RNA-Seq study was performed, and we could identify more than 760 genes differentially expressed in Atmit1 Atmit2. Our results show that Atmit1 Atmit2 double homozygous mutant plants misregulate genes involved in iron transport, coumarin metabolism, hormone metabolism, root development, and stress-related response. The phenotypes observed, such as pinoid stems and fused cotyledons, in Atmit1 Atmit2 double homozygous mutant plants may suggest defects in auxin homeostasis. Unexpectedly, we observed a possible phenomenon of T-DNA suppression in the next generation of Atmit1 Atmit2 double homozygous mutant plants, correlating with increased splicing of the AtMIT2 intron containing the T-DNA and the suppression of the phenotypes observed in the first generation of the double mutant plants. In these plants with a suppressed phenotype, no differences were observed in the oxygen consumption rate of isolated mitochondria; however, the molecular analysis of gene expression markers, AOX1a, UPOX, and MSM1, for mitochondrial and oxidative stress showed that these plants express a degree of mitochondrial perturbation. Finally, we could establish by a targeted proteomic analysis that a protein level of 30% of MIT2, in the absence of MIT1, is enough for normal plant growth under iron-sufficient conditions.
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Affiliation(s)
- Joaquín Vargas
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Isabel Gómez
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Elena A. Vidal
- ANID-Millennium Science Initiative Program-Millennium Institute for Integrative Biology (iBio), Santiago 8331150, Chile
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Ingeniería y Tecnología, Universidad Mayor, Santiago 8580745, Chile
- Escuela de Biotecnología, Facultad de Ciencias, Ingeniería y Tecnología, Universidad Mayor, Santiago 8580745, Chile
| | - Chun Pong Lee
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Bayliss Building M316, Crawley, WA 6009, Australia
| | - A. Harvey Millar
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Bayliss Building M316, Crawley, WA 6009, Australia
| | - Xavier Jordana
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Hannetz Roschzttardtz
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
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5
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Vargas J, Roschzttardtz H. Perls/DAB Staining to Examine Iron Distribution in Arabidopsis Embryos. Methods Mol Biol 2023; 2665:173-176. [PMID: 37166600 DOI: 10.1007/978-1-0716-3183-6_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Iron is accumulated in Arabidopsis embryos during seed maturation. Where iron localizes in seed and embryo is important information for seed research. Iron detection can be performed in an inexpensive manner using Perls staining, based on the Prussian blue complex formation. After this first step, DAB intensification can be performed in order to visualize easily where iron pools are located in isolated embryos.
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Affiliation(s)
- Joaquín Vargas
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Hannetz Roschzttardtz
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
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Grant-Grant S, Schaffhauser M, Baeza-Gonzalez P, Gao F, Conéjéro G, Vidal EA, Gaymard F, Dubos C, Curie C, Roschzttardtz H. B3 Transcription Factors Determine Iron Distribution and FERRITIN Gene Expression in Embryo but Do Not Control Total Seed Iron Content. Front Plant Sci 2022; 13:870078. [PMID: 35599858 PMCID: PMC9120844 DOI: 10.3389/fpls.2022.870078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Accepted: 03/21/2022] [Indexed: 05/26/2023]
Abstract
Iron is an essential micronutrient for humans and other organisms. Its deficiency is one of the leading causes of anemia worldwide. The world health organization has proposed that an alternative to increasing iron content in food is through crop biofortification. One of the most consumed part of crops is the seed, however, little is known about how iron accumulation in seed occurs and how it is regulated. B3 transcription factors play a critical role in the accumulation of storage compounds such as proteins and lipids. Their role in seed maturation has been well characterized. However, their relevance in accumulation and distribution of micronutrients like iron remains unknown. In Arabidopsis thaliana and other plant models, three master regulators belonging to the B3 transcription factors family have been identified: FUSCA3 (FUS3), LEAFY COTYLEDON2 (LEC2), and ABSCISIC ACID INSENSITIVE 3 (ABI3). In this work, we studied how seed iron homeostasis is affected in B3 transcription factors mutants using histological and molecular approaches. We determined that iron distribution is modified in abi3, lec2, and fus3 embryo mutants. For abi3-6 and fus3-3 mutant embryos, iron was less accumulated in vacuoles of cells surrounding provasculature compared with wild type embryos. lec2-1 embryos showed no difference in the pattern of iron distribution in hypocotyl, but a dramatic decrease of iron was observed in cotyledons. Interestingly, for the three mutant genotypes, total iron content in dry mutant seeds showed no difference compared to wild type. At the molecular level, we showed that genes encoding the iron storage ferritins proteins are misregulated in mutant seeds. Altogether our results support a role of the B3 transcription factors ABI3, LEC2, and FUS3 in maintaining iron homeostasis in Arabidopsis embryos.
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Affiliation(s)
- Susana Grant-Grant
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Macarena Schaffhauser
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pablo Baeza-Gonzalez
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Fei Gao
- IPSiM, Univ. Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France
| | - Geneviève Conéjéro
- IPSiM, Univ. Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France
| | - Elena A. Vidal
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Ingeniería y Tecnología, Universidad Mayor, Santiago, Chile
- Escuela de Biotecnología, Facultad de Ciencias, Ingeniería y Tecnología, Universidad Mayor, Santiago, Chile
- Agencia Nacional de Investigación y Desarrollo ANID-Millennium Science Initiative Program, Millennium Institute for Integrative Biology (iBio), Santiago, Chile
| | - Frederic Gaymard
- IPSiM, Univ. Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France
| | - Christian Dubos
- IPSiM, Univ. Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France
| | - Catherine Curie
- IPSiM, Univ. Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France
| | - Hannetz Roschzttardtz
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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7
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Bozinovic F, Cavieres G, Martel SI, Alruiz JM, Molina AN, Roschzttardtz H, Rezende EL. Thermal effects vary predictably across levels of organization: empirical results and theoretical basis. Proc Biol Sci 2020; 287:20202508. [PMID: 33143579 PMCID: PMC7735269 DOI: 10.1098/rspb.2020.2508] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 10/15/2020] [Indexed: 12/19/2022] Open
Abstract
Thermal performance curves have provided a common framework to study the impact of temperature in biological systems. However, few generalities have emerged to date. Here, we combine an experimental approach with theoretical analyses to demonstrate that performance curves are expected to vary predictably with the levels of biological organization. We measured rates of enzymatic reactions, organismal performance and population viability in Drosophila acclimated to different thermal conditions and show that performance curves become narrower with thermal optima shifting towards lower temperatures at higher levels or organization. We then explain these results on theoretical grounds, showing that this pattern reflects the cumulative impact of asymmetric thermal effects that piles up with complexity. These results and the proposed framework are important to understand how organisms, populations and ecological communities might respond to changing thermal conditions.
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Affiliation(s)
- Francisco Bozinovic
- Departamento de Ecología, Center of Applied Ecology and Sustainability (CAPES), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 6513677, Chile
| | - Grisel Cavieres
- Departamento de Ecología, Center of Applied Ecology and Sustainability (CAPES), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 6513677, Chile
| | - Sebastián I. Martel
- Departamento de Ecología, Center of Applied Ecology and Sustainability (CAPES), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 6513677, Chile
| | - José M. Alruiz
- Departamento de Ecología, Center of Applied Ecology and Sustainability (CAPES), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 6513677, Chile
| | - Andrés N. Molina
- Departamento de Ecología, Center of Applied Ecology and Sustainability (CAPES), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 6513677, Chile
| | - Hannetz Roschzttardtz
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 6513677, Chile
| | - Enrico L. Rezende
- Departamento de Ecología, Center of Applied Ecology and Sustainability (CAPES), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 6513677, Chile
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8
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Roschzttardtz H, Gaymard F, Dubos C. Transcriptional Regulation of Iron Distribution in Seeds: A Perspective. Front Plant Sci 2020; 11:725. [PMID: 32547590 PMCID: PMC7273024 DOI: 10.3389/fpls.2020.00725] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 05/06/2020] [Indexed: 05/28/2023]
Abstract
Several transcription factors have been involved in the regulation of gene expression during seed development. Nutritional reserves, including iron, are principally accumulated during seed maturation stages. Using the model plant Arabidopsis thaliana, it has been shown that iron is stored during seed development in vacuoles of the endodermis cell layer. During seed germination, these iron reserves are remobilized and used by the seedling during the heterotrophic to autotrophic metabolism switch. To date, no information about how iron distribution is genetically regulated has been reported.
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Affiliation(s)
- Hannetz Roschzttardtz
- Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Frederic Gaymard
- BPMP, University of Montpellier, CNRS, INRAE, SupAgro, Montpellier, France
| | - Christian Dubos
- BPMP, University of Montpellier, CNRS, INRAE, SupAgro, Montpellier, France
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9
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Balparda M, Armas AM, Estavillo GM, Roschzttardtz H, Pagani MA, Gomez-Casati DF. The PAP/SAL1 retrograde signaling pathway is involved in iron homeostasis. Plant Mol Biol 2020; 102:323-337. [PMID: 31900819 DOI: 10.1007/s11103-019-00950-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 12/16/2019] [Indexed: 05/24/2023]
Abstract
There is a link between PAP/SAL retrograde pathway, ethylene signaling and Fe metabolism in Arabidopsis. Nuclear gene expression is regulated by a diversity of retrograde signals that travel from organelles to the nucleus in a lineal or classical model. One such signal molecule is 3'-phosphoadenisine-5'-phosphate (PAP) and it's in vivo levels are regulated by SAL1/FRY1, a phosphatase enzyme located in chloroplast and mitochondria. This metabolite inhibits the action of a group of exorribonucleases which participate in post-transcriptional gene expression regulation. Transcriptome analysis of Arabidopsis thaliana mutant plants in PAP-SAL1 pathway revealed that the ferritin genes AtFER1, AtFER3, and AtFER4 are up-regulated. In this work we studied Fe metabolism in three different mutants of the PAP/SAL1 retrograde pathway. Mutant plants showed increased Fe accumulation in roots, shoots and seeds when grown in Fe-sufficient condition, and a constitutive activation of the Strategy I Fe uptake genes. As a consequence, they grew more vigorously than wild type plants in Fe-deficient medium. However, when mutant plants grown in Fe-deficient conditions were sprayed with Fe in their leaves, they were unable to deactivate root Fe uptake. Ethylene synthesis inhibition revert the constitutive Fe uptake phenotype. We propose that there is a link between PAP/SAL pathway, ethylene signaling and Fe metabolism.
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Affiliation(s)
- Manuel Balparda
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI), CONICET-Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Alejandro M Armas
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI), CONICET-Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | | | - Hannetz Roschzttardtz
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - María A Pagani
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI), CONICET-Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina.
| | - Diego F Gomez-Casati
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI), CONICET-Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina.
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10
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Gao F, Robe K, Bettembourg M, Navarro N, Rofidal V, Santoni V, Gaymard F, Vignols F, Roschzttardtz H, Izquierdo E, Dubos C. The Transcription Factor bHLH121 Interacts with bHLH105 (ILR3) and Its Closest Homologs to Regulate Iron Homeostasis in Arabidopsis. Plant Cell 2020; 32:508-524. [PMID: 31776233 PMCID: PMC7008485 DOI: 10.1105/tpc.19.00541] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 11/04/2019] [Accepted: 11/21/2019] [Indexed: 05/20/2023]
Abstract
Iron (Fe) is an essential micronutrient for plant growth and development. Any defects in the maintenance of Fe homeostasis will alter plant productivity and the quality of their derived products. In Arabidopsis (Arabidopsis thaliana), the transcription factor ILR3 plays a central role in controlling Fe homeostasis. In this study, we identified bHLH121 as an ILR3-interacting transcription factor. Interaction studies showed that bHLH121 also interacts with the three closest homologs of ILR3 (i.e., basic-helix-loop-helix 34 [bHLH34], bHLH104, and bHLH115). bhlh121 loss-of-function mutants displayed severe defects in Fe homeostasis that could be reverted by exogenous Fe supply. bHLH121 acts as a direct transcriptional activator of key genes involved in the Fe regulatory network, including bHLH38, bHLH39, bHLH100, bHLH101, POPEYE, BRUTUS, and BRUTUS LIKE1, as well as IRONMAN1 and IRONMAN2 In addition, bHLH121 is necessary for activating the expression of transcription factor gene FIT in response to Fe deficiency via an indirect mechanism. bHLH121 is expressed throughout the plant body, and its expression is not affected by Fe availability. By contrast, Fe availability affects the cellular localization of bHLH121 protein in roots. Altogether, these data show that bHLH121 is a regulator of Fe homeostasis that acts upstream of FIT in concert with ILR3 and its closest homologs.
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Affiliation(s)
- Fei Gao
- Biochimie et Physiologie Moléculaire des Plantes, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, SupAgro, 34060 Montpellier, France
| | - Kevin Robe
- Biochimie et Physiologie Moléculaire des Plantes, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, SupAgro, 34060 Montpellier, France
| | - Mathilde Bettembourg
- Biochimie et Physiologie Moléculaire des Plantes, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, SupAgro, 34060 Montpellier, France
| | - Nathalia Navarro
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, 8331150, Santiago, Chile
| | - Valérie Rofidal
- Biochimie et Physiologie Moléculaire des Plantes, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, SupAgro, 34060 Montpellier, France
| | - Véronique Santoni
- Biochimie et Physiologie Moléculaire des Plantes, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, SupAgro, 34060 Montpellier, France
| | - Frédéric Gaymard
- Biochimie et Physiologie Moléculaire des Plantes, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, SupAgro, 34060 Montpellier, France
| | - Florence Vignols
- Biochimie et Physiologie Moléculaire des Plantes, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, SupAgro, 34060 Montpellier, France
| | - Hannetz Roschzttardtz
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, 8331150, Santiago, Chile
| | - Esther Izquierdo
- Biochimie et Physiologie Moléculaire des Plantes, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, SupAgro, 34060 Montpellier, France
| | - Christian Dubos
- Biochimie et Physiologie Moléculaire des Plantes, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, SupAgro, 34060 Montpellier, France
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Tissot N, Robe K, Gao F, Grant-Grant S, Boucherez J, Bellegarde F, Maghiaoui A, Marcelin R, Izquierdo E, Benhamed M, Martin A, Vignols F, Roschzttardtz H, Gaymard F, Briat JF, Dubos C. Transcriptional integration of the responses to iron availability in Arabidopsis by the bHLH factor ILR3. New Phytol 2019; 223:1433-1446. [PMID: 30773647 DOI: 10.1111/nph.15753] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 02/12/2019] [Indexed: 05/21/2023]
Abstract
Iron (Fe) homeostasis is crucial for all living organisms. In mammals, an integrated posttranscriptional mechanism couples the regulation of both Fe deficiency and Fe excess responses. Whether in plants an integrated control mechanism involving common players regulates responses both to deficiency and to excess is still to be determined. In this study, molecular, genetic and biochemical approaches were used to investigate transcriptional responses to both Fe deficiency and excess. A transcriptional activator of responses to Fe shortage in Arabidopsis, called bHLH105/ILR3, was found to also negatively regulate the expression of ferritin genes, which are markers of the plant's response to Fe excess. Further investigations revealed that ILR3 repressed the expression of several structural genes that function in the control of Fe homeostasis. ILR3 interacts directly with the promoter of its target genes, and repressive activity was conferred by its dimerisation with bHLH47/PYE. Last, this study highlighted that important facets of plant growth in response to Fe deficiency or excess rely on ILR3 activity. Altogether, the data presented herein support that ILR3 is at the centre of the transcriptional regulatory network that controls Fe homeostasis in Arabidopsis, in which it acts as both transcriptional activator and repressor.
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Affiliation(s)
- Nicolas Tissot
- BPMP, Univ Montpellier, CNRS, INRA, SupAgro, 34060, Montpellier, France
| | - Kevin Robe
- BPMP, Univ Montpellier, CNRS, INRA, SupAgro, 34060, Montpellier, France
| | - Fei Gao
- BPMP, Univ Montpellier, CNRS, INRA, SupAgro, 34060, Montpellier, France
| | - Susana Grant-Grant
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, 8331150, Santiago, Chile
| | - Jossia Boucherez
- BPMP, Univ Montpellier, CNRS, INRA, SupAgro, 34060, Montpellier, France
| | - Fanny Bellegarde
- BPMP, Univ Montpellier, CNRS, INRA, SupAgro, 34060, Montpellier, France
| | - Amel Maghiaoui
- BPMP, Univ Montpellier, CNRS, INRA, SupAgro, 34060, Montpellier, France
| | - Romain Marcelin
- BPMP, Univ Montpellier, CNRS, INRA, SupAgro, 34060, Montpellier, France
| | - Esther Izquierdo
- BPMP, Univ Montpellier, CNRS, INRA, SupAgro, 34060, Montpellier, France
| | - Moussa Benhamed
- Institut of Plant Sciences Paris-Saclay (IPS2), UMR 9213/UMR1403, CNRS, INRA, Université Paris-Sud, Université d'Evry, Université Paris-Diderot, Sorbonne Paris-Cité, Bâtiment 630, 91405, Orsay, France
| | - Antoine Martin
- BPMP, Univ Montpellier, CNRS, INRA, SupAgro, 34060, Montpellier, France
| | - Florence Vignols
- BPMP, Univ Montpellier, CNRS, INRA, SupAgro, 34060, Montpellier, France
| | - Hannetz Roschzttardtz
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, 8331150, Santiago, Chile
| | - Frédéric Gaymard
- BPMP, Univ Montpellier, CNRS, INRA, SupAgro, 34060, Montpellier, France
| | | | - Christian Dubos
- BPMP, Univ Montpellier, CNRS, INRA, SupAgro, 34060, Montpellier, France
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Roschzttardtz H, González-Guerrero M, Gomez-Casati DF. Editorial: Metallic Micronutrient Homeostasis in Plants. Front Plant Sci 2019; 10:927. [PMID: 31379906 PMCID: PMC6652723 DOI: 10.3389/fpls.2019.00927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 07/02/2019] [Indexed: 06/10/2023]
Affiliation(s)
- Hannetz Roschzttardtz
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Manuel González-Guerrero
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA), Universidad Politécnica de Madrid, Madrid, Spain
| | - Diego F. Gomez-Casati
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Rosario, Argentina
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13
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Ibeas MA, Grant-Grant S, Coronas MF, Vargas-Pérez JI, Navarro N, Abreu I, Castillo-Michel H, Avalos-Cembrano N, Paez Valencia J, Perez F, González-Guerrero M, Roschzttardtz H. The Diverse Iron Distribution in Eudicotyledoneae Seeds: From Arabidopsis to Quinoa. Front Plant Sci 2018; 9:1985. [PMID: 30697224 PMCID: PMC6341002 DOI: 10.3389/fpls.2018.01985] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 12/20/2018] [Indexed: 05/08/2023]
Abstract
Seeds accumulate iron during embryo maturation stages of embryogenesis. Using Arabidopsis thaliana as model plant, it has been described that mature embryos accumulate iron within a specific cell layer, the endodermis. This distribution pattern was conserved in most of the analyzed members from Brassicales, with the exception of the basal Vasconcellea pubescens that also showed elevated amounts of iron in cortex cells. To determine whether the V. pubescens iron distribution was indicative of a wider pattern in non-Brassicales Eudicotyledoneae, we studied iron distribution pattern in different embryos belonging to plant species from different Orders from Eudicotyledoneae and one basal from Magnoliidae. The results obtained indicate that iron distribution in A. thaliana embryo is an extreme case of apomorphic character found in Brassicales, not-extensive to the rest of Eudicotyledoneae.
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Affiliation(s)
- Miguel Angel Ibeas
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Susana Grant-Grant
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Maria Fernanda Coronas
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Nathalia Navarro
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Isidro Abreu
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA), Universidad Politécnica de Madrid, Madrid, Spain
| | | | | | - Julio Paez Valencia
- Department of Botany, University of Wisconsin–Madison, Madison, WI, United States
| | - Fernanda Perez
- Departamento de Ecología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Manuel González-Guerrero
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA), Universidad Politécnica de Madrid, Madrid, Spain
| | - Hannetz Roschzttardtz
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- *Correspondence: Hannetz Roschzttardtz,
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Ibeas MA, Grant-Grant S, Navarro N, Perez MF, Roschzttardtz H. Dynamic Subcellular Localization of Iron during Embryo Development in Brassicaceae Seeds. Front Plant Sci 2017; 8:2186. [PMID: 29312417 PMCID: PMC5744184 DOI: 10.3389/fpls.2017.02186] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 12/12/2017] [Indexed: 05/08/2023]
Abstract
Iron is an essential micronutrient for plants. Little is know about how iron is loaded in embryo during seed development. In this article we used Perls/DAB staining in order to reveal iron localization at the cellular and subcellular levels in different Brassicaceae seed species. In dry seeds of Brassica napus, Nasturtium officinale, Lepidium sativum, Camelina sativa, and Brassica oleracea iron localizes in vacuoles of cells surrounding provasculature in cotyledons and hypocotyl. Using B. napus and N. officinale as model plants we determined where iron localizes during seed development. Our results indicate that iron is not detectable by Perls/DAB staining in heart stage embryo cells. Interestingly, at torpedo development stage iron localizes in nuclei of different cells type, including integument, free cell endosperm and almost all embryo cells. Later, iron is detected in cytoplasmic structures in different embryo cell types. Our results indicate that iron accumulates in nuclei in specific stages of embryo maturation before to be localized in vacuoles of cells surrounding provasculature in mature seeds.
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Affiliation(s)
- Miguel A. Ibeas
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Susana Grant-Grant
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Nathalia Navarro
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - M. F. Perez
- Departamento de Ecología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Hannetz Roschzttardtz
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Santiago, Chile
- *Correspondence: Hannetz Roschzttardtz,
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15
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Roschzttardtz H, Bustos S, Coronas MF, Ibeas MA, Grant-Grant S, Vargas-Pérez J. Increasing Provasculature Complexity in the Arabidopsis Embryo May Increase Total Iron Content in Seeds: A Hypothesis. Front Plant Sci 2017. [PMID: 28642774 PMCID: PMC5463184 DOI: 10.3389/fpls.2017.00960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Anemia due to iron deficiency is a worldwide issue, affecting mainly children and women. Seed iron is a major source of this micronutrient for feeding, however, in most crops these levels are too low to meet daily needs. Thus, increasing iron allocation and its storage in seeds can represent an important step to enhance iron provision for humans and animals. Our knowledge on seed iron homeostasis is mainly based on studies performed in the model plant Arabidopsis thaliana, where iron accumulates in endodermis cells surrounding the embryo provasculature. It has been reported that cotyledon provasculature pattern complexity can be modified, thus we hypothesize that changes in the complexity of embryo vein patterns may affect total iron content in Arabidopsis seeds. This approach could be used as basis to develop strategies aimed to biofortify seeds.
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Spitzer C, Li F, Buono R, Roschzttardtz H, Chung T, Zhang M, Osteryoung KW, Vierstra RD, Otegui MS. The endosomal protein CHARGED MULTIVESICULAR BODY PROTEIN1 regulates the autophagic turnover of plastids in Arabidopsis. Plant Cell 2015; 27:391-402. [PMID: 25649438 PMCID: PMC4456926 DOI: 10.1105/tpc.114.135939] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Revised: 12/25/2014] [Accepted: 01/17/2015] [Indexed: 05/18/2023]
Abstract
Endosomal Sorting Complex Required for Transport (ESCRT)-III proteins mediate membrane remodeling and the release of endosomal intraluminal vesicles into multivesicular bodies. Here, we show that the ESCRT-III subunit paralogs CHARGED MULTIVESICULAR BODY PROTEIN1 (CHMP1A) and CHMP1B are required for autophagic degradation of plastid proteins in Arabidopsis thaliana. Similar to autophagy mutants, chmp1a chmp1b (chmp1) plants hyperaccumulated plastid components, including proteins involved in plastid division. The autophagy machinery directed the release of bodies containing plastid material into the cytoplasm, whereas CHMP1A and B were required for delivery of these bodies to the vacuole. Autophagy was upregulated in chmp1 as indicated by an increase in vacuolar green fluorescent protein (GFP) cleavage from the autophagic reporter GFP-ATG8. However, autophagic degradation of the stromal cargo RECA-GFP was drastically reduced in the chmp1 plants upon starvation, suggesting that CHMP1 mediates the efficient delivery of autophagic plastid cargo to the vacuole. Consistent with the compromised degradation of plastid proteins, chmp1 plastids show severe morphological defects and aberrant division. We propose that CHMP1 plays a direct role in the autophagic turnover of plastid constituents.
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Affiliation(s)
- Christoph Spitzer
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Faqiang Li
- Department of Genetics, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Rafael Buono
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | | | - Taijoon Chung
- Department of Genetics, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Min Zhang
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | | | - Richard D Vierstra
- Department of Genetics, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Marisa S Otegui
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin 53706 Department of Genetics, University of Wisconsin-Madison, Madison, Wisconsin 53706
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17
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Roschzttardtz H, Paez-Valencia J, Dittakavi T, Jali S, Reyes FC, Baisa G, Anne P, Gissot L, Palauqui JC, Masson PH, Bednarek SY, Otegui MS. The VASCULATURE COMPLEXITY AND CONNECTIVITY gene encodes a plant-specific protein required for embryo provasculature development. Plant Physiol 2014; 166:889-902. [PMID: 25149602 PMCID: PMC4213116 DOI: 10.1104/pp.114.246314] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 08/21/2014] [Indexed: 05/23/2023]
Abstract
The molecular mechanisms by which vascular tissues acquire their identities are largely unknown. Here, we report on the identification and characterization of VASCULATURE COMPLEXITY AND CONNECTIVITY (VCC), a member of a 15-member, plant-specific gene family in Arabidopsis (Arabidopsis thaliana) that encodes proteins of unknown function with four predicted transmembrane domains. Homozygous vcc mutants displayed cotyledon vein networks of reduced complexity and disconnected veins. Similar disconnections or gaps were observed in the provasculature of vcc embryos, indicating that defects in vein connectivity appear early in mutant embryo development. Consistently, the overexpression of VCC leads to an unusually high proportion of cotyledons with high-complexity vein networks. Neither auxin distribution nor the polar localization of the auxin efflux carrier were affected in vcc mutant embryos. Expression of VCC was detected in developing embryos and procambial, cambial, and vascular cells of cotyledons, leaves, roots, hypocotyls, and anthers. To evaluate possible genetic interactions with other genes that control vasculature patterning in embryos, we generated a double mutant for VCC and OCTOPUS (OPS). The vcc ops double mutant embryos showed a complete loss of high-complexity vascular networks in cotyledons and a drastic increase in both provascular and vascular disconnections. In addition, VCC and OPS interact physically, suggesting that VCC and OPS are part of a complex that controls cotyledon vascular complexity.
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Affiliation(s)
- Hannetz Roschzttardtz
- Department of Botany (H.R., J.P.-V., T.D., F.C.R., M.S.O.), Department of Genetics (S.J., P.H.M., M.S.O.), and Department of Biochemistry (G.B., S.Y.B.), University of Wisconsin, Madison, Wisconsin 53706;Great Lakes Bioenergy Research Center, Madison, Wisconsin 53706 (H.R., S.J., G.B.); andInstitut National de la Recherche Agronomique and AgroParisTech, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Saclay Plant Science, 78000 Versailles, France (P.A., L.G., J.-C.P.)
| | - Julio Paez-Valencia
- Department of Botany (H.R., J.P.-V., T.D., F.C.R., M.S.O.), Department of Genetics (S.J., P.H.M., M.S.O.), and Department of Biochemistry (G.B., S.Y.B.), University of Wisconsin, Madison, Wisconsin 53706;Great Lakes Bioenergy Research Center, Madison, Wisconsin 53706 (H.R., S.J., G.B.); andInstitut National de la Recherche Agronomique and AgroParisTech, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Saclay Plant Science, 78000 Versailles, France (P.A., L.G., J.-C.P.)
| | - Tejaswi Dittakavi
- Department of Botany (H.R., J.P.-V., T.D., F.C.R., M.S.O.), Department of Genetics (S.J., P.H.M., M.S.O.), and Department of Biochemistry (G.B., S.Y.B.), University of Wisconsin, Madison, Wisconsin 53706;Great Lakes Bioenergy Research Center, Madison, Wisconsin 53706 (H.R., S.J., G.B.); andInstitut National de la Recherche Agronomique and AgroParisTech, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Saclay Plant Science, 78000 Versailles, France (P.A., L.G., J.-C.P.)
| | - Sathya Jali
- Department of Botany (H.R., J.P.-V., T.D., F.C.R., M.S.O.), Department of Genetics (S.J., P.H.M., M.S.O.), and Department of Biochemistry (G.B., S.Y.B.), University of Wisconsin, Madison, Wisconsin 53706;Great Lakes Bioenergy Research Center, Madison, Wisconsin 53706 (H.R., S.J., G.B.); andInstitut National de la Recherche Agronomique and AgroParisTech, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Saclay Plant Science, 78000 Versailles, France (P.A., L.G., J.-C.P.)
| | - Francisca C Reyes
- Department of Botany (H.R., J.P.-V., T.D., F.C.R., M.S.O.), Department of Genetics (S.J., P.H.M., M.S.O.), and Department of Biochemistry (G.B., S.Y.B.), University of Wisconsin, Madison, Wisconsin 53706;Great Lakes Bioenergy Research Center, Madison, Wisconsin 53706 (H.R., S.J., G.B.); andInstitut National de la Recherche Agronomique and AgroParisTech, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Saclay Plant Science, 78000 Versailles, France (P.A., L.G., J.-C.P.)
| | - Gary Baisa
- Department of Botany (H.R., J.P.-V., T.D., F.C.R., M.S.O.), Department of Genetics (S.J., P.H.M., M.S.O.), and Department of Biochemistry (G.B., S.Y.B.), University of Wisconsin, Madison, Wisconsin 53706;Great Lakes Bioenergy Research Center, Madison, Wisconsin 53706 (H.R., S.J., G.B.); andInstitut National de la Recherche Agronomique and AgroParisTech, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Saclay Plant Science, 78000 Versailles, France (P.A., L.G., J.-C.P.)
| | - Pauline Anne
- Department of Botany (H.R., J.P.-V., T.D., F.C.R., M.S.O.), Department of Genetics (S.J., P.H.M., M.S.O.), and Department of Biochemistry (G.B., S.Y.B.), University of Wisconsin, Madison, Wisconsin 53706;Great Lakes Bioenergy Research Center, Madison, Wisconsin 53706 (H.R., S.J., G.B.); andInstitut National de la Recherche Agronomique and AgroParisTech, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Saclay Plant Science, 78000 Versailles, France (P.A., L.G., J.-C.P.)
| | - Lionel Gissot
- Department of Botany (H.R., J.P.-V., T.D., F.C.R., M.S.O.), Department of Genetics (S.J., P.H.M., M.S.O.), and Department of Biochemistry (G.B., S.Y.B.), University of Wisconsin, Madison, Wisconsin 53706;Great Lakes Bioenergy Research Center, Madison, Wisconsin 53706 (H.R., S.J., G.B.); andInstitut National de la Recherche Agronomique and AgroParisTech, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Saclay Plant Science, 78000 Versailles, France (P.A., L.G., J.-C.P.)
| | - Jean-Christophe Palauqui
- Department of Botany (H.R., J.P.-V., T.D., F.C.R., M.S.O.), Department of Genetics (S.J., P.H.M., M.S.O.), and Department of Biochemistry (G.B., S.Y.B.), University of Wisconsin, Madison, Wisconsin 53706;Great Lakes Bioenergy Research Center, Madison, Wisconsin 53706 (H.R., S.J., G.B.); andInstitut National de la Recherche Agronomique and AgroParisTech, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Saclay Plant Science, 78000 Versailles, France (P.A., L.G., J.-C.P.)
| | - Patrick H Masson
- Department of Botany (H.R., J.P.-V., T.D., F.C.R., M.S.O.), Department of Genetics (S.J., P.H.M., M.S.O.), and Department of Biochemistry (G.B., S.Y.B.), University of Wisconsin, Madison, Wisconsin 53706;Great Lakes Bioenergy Research Center, Madison, Wisconsin 53706 (H.R., S.J., G.B.); andInstitut National de la Recherche Agronomique and AgroParisTech, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Saclay Plant Science, 78000 Versailles, France (P.A., L.G., J.-C.P.)
| | - Sebastian Y Bednarek
- Department of Botany (H.R., J.P.-V., T.D., F.C.R., M.S.O.), Department of Genetics (S.J., P.H.M., M.S.O.), and Department of Biochemistry (G.B., S.Y.B.), University of Wisconsin, Madison, Wisconsin 53706;Great Lakes Bioenergy Research Center, Madison, Wisconsin 53706 (H.R., S.J., G.B.); andInstitut National de la Recherche Agronomique and AgroParisTech, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Saclay Plant Science, 78000 Versailles, France (P.A., L.G., J.-C.P.)
| | - Marisa S Otegui
- Department of Botany (H.R., J.P.-V., T.D., F.C.R., M.S.O.), Department of Genetics (S.J., P.H.M., M.S.O.), and Department of Biochemistry (G.B., S.Y.B.), University of Wisconsin, Madison, Wisconsin 53706;Great Lakes Bioenergy Research Center, Madison, Wisconsin 53706 (H.R., S.J., G.B.); andInstitut National de la Recherche Agronomique and AgroParisTech, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Saclay Plant Science, 78000 Versailles, France (P.A., L.G., J.-C.P.)
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18
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Reyes FC, Buono RA, Roschzttardtz H, Di Rubbo S, Yeun LH, Russinova E, Otegui MS. A novel endosomal sorting complex required for transport (ESCRT) component in Arabidopsis thaliana controls cell expansion and development. J Biol Chem 2014; 289:4980-8. [PMID: 24385429 DOI: 10.1074/jbc.m113.529685] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
ESCRT proteins mediate membrane remodeling and scission events and are essential for endosomal sorting of plasma membrane proteins for degradation. We have identified a novel, plant-specific ESCRT component called PROS (POSITIVE REGULATOR OF SKD1) in Arabidopsis thaliana. PROS has a strong positive effect on the in vitro ATPase activity of SKD1 (also known as Vacuolar Protein Sorting 4 or VPS4), a critical component required for ESCRT-III disassembly and endosomal vesiculation. PROS interacts with both SKD1 and the SKD1-positive regulator LIP5/VTA1. We have identified a putative MIM domain within PROS that mediate the interaction with the MIT domain of SKD1. Interestingly, whereas MIM domains are commonly found at the C terminus of ESCRT-III subunits, the PROS MIM domain is internal. The heterologous expression of PROS in yeast mutant cells lacking Vta1p partially rescues endosomal sorting defects. PROS is expressed in most tissues and cells types in Arabidopsis thaliana. Silencing of PROS leads to reduced cell expansion and abnormal organ growth.
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Affiliation(s)
- Francisca C Reyes
- From the Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin 53706
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19
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Divol F, Couch D, Conéjéro G, Roschzttardtz H, Mari S, Curie C. The Arabidopsis YELLOW STRIPE LIKE4 and 6 transporters control iron release from the chloroplast. Plant Cell 2013; 25:1040-1055. [PMID: 23512854 DOI: 10.1105/tpc112107672] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In most plant cell types, the chloroplast represents the largest sink for iron, which is both essential for chloroplast metabolism and prone to cause oxidative damage. Here, we show that to buffer the potentially harmful effects of iron, besides ferritins for storage, the chloroplast is equipped with specific iron transporters that respond to iron toxicity by removing iron from the chloroplast. We describe two transporters of the YELLOW STRIPE1-LIKE family from Arabidopsis thaliana, YSL4 and YSL6, which are likely to fulfill this function. Knocking out both YSL4 and YSL6 greatly reduces the plant's ability to cope with excess iron. Biochemical and immunolocalization analyses showed that YSL6 resides in the chloroplast envelope. Elemental analysis and histochemical staining indicate that iron is trapped in the chloroplasts of the ysl4 ysl6 double mutants, which also accumulate ferritins. Also, vacuolar iron remobilization and NRAMP3/4 expression are inhibited. Furthermore, ubiquitous expression of YSL4 or YSL6 dramatically reduces plant tolerance to iron deficiency and decreases chloroplastic iron content. These data demonstrate a fundamental role for YSL4 and YSL6 in managing chloroplastic iron. YSL4 and YSL6 expression patterns support their physiological role in detoxifying iron during plastid dedifferentiation occurring in embryogenesis and senescence.
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Affiliation(s)
- Fanchon Divol
- Biochimie et Physiologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5004/Institut National de la Recherche Agronomique/SupAgro/Université Montpellier 1, F-34060 Montpellier cedex 2, France
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Divol F, Couch D, Conéjéro G, Roschzttardtz H, Mari S, Curie C. The Arabidopsis YELLOW STRIPE LIKE4 and 6 transporters control iron release from the chloroplast. Plant Cell 2013; 25:1040-55. [PMID: 23512854 PMCID: PMC3634676 DOI: 10.1105/tpc.112.107672] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 02/20/2013] [Accepted: 02/26/2013] [Indexed: 05/18/2023]
Abstract
In most plant cell types, the chloroplast represents the largest sink for iron, which is both essential for chloroplast metabolism and prone to cause oxidative damage. Here, we show that to buffer the potentially harmful effects of iron, besides ferritins for storage, the chloroplast is equipped with specific iron transporters that respond to iron toxicity by removing iron from the chloroplast. We describe two transporters of the YELLOW STRIPE1-LIKE family from Arabidopsis thaliana, YSL4 and YSL6, which are likely to fulfill this function. Knocking out both YSL4 and YSL6 greatly reduces the plant's ability to cope with excess iron. Biochemical and immunolocalization analyses showed that YSL6 resides in the chloroplast envelope. Elemental analysis and histochemical staining indicate that iron is trapped in the chloroplasts of the ysl4 ysl6 double mutants, which also accumulate ferritins. Also, vacuolar iron remobilization and NRAMP3/4 expression are inhibited. Furthermore, ubiquitous expression of YSL4 or YSL6 dramatically reduces plant tolerance to iron deficiency and decreases chloroplastic iron content. These data demonstrate a fundamental role for YSL4 and YSL6 in managing chloroplastic iron. YSL4 and YSL6 expression patterns support their physiological role in detoxifying iron during plastid dedifferentiation occurring in embryogenesis and senescence.
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Roschzttardtz H, Conéjéro G, Divol F, Alcon C, Verdeil JL, Curie C, Mari S. New insights into Fe localization in plant tissues. Front Plant Sci 2013; 4:350. [PMID: 24046774 PMCID: PMC3764369 DOI: 10.3389/fpls.2013.00350] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 08/20/2013] [Indexed: 05/02/2023]
Abstract
Deciphering cellular iron (Fe) homeostasis requires having access to both quantitative and qualitative information on the subcellular pools of Fe in tissues and their dynamics within the cells. We have taken advantage of the Perls/DAB Fe staining procedure to perform a systematic analysis of Fe distribution in roots, leaves and reproductive organs of the model plant Arabidopsis thaliana, using wild-type and mutant genotypes affected in iron transport and storage. Roots of soil-grown plants accumulate iron in the apoplast of the central cylinder, a pattern that is strongly intensified when the citrate effluxer FRD3 is not functional, thus stressing the importance of citrate in the apoplastic movement of Fe. In leaves, Fe level is low and only detected in and around vascular tissues. In contrast, Fe staining in leaves of iron-treated plants extends in the surrounding mesophyll cells where Fe deposits, likely corresponding to Fe-ferritin complexes, accumulate in the chloroplasts. The loss of ferritins in the fer1,3,4 triple mutant provoked a massive accumulation of Fe in the apoplastic space, suggesting that in the absence of iron buffering in the chloroplast, cells activate iron efflux and/or repress iron influx to limit the amount of iron in the cell. In flowers, Perls/DAB staining has revealed a major sink for Fe in the anthers. In particular, developing pollen grains accumulate detectable amounts of Fe in small-size intracellular bodies that aggregate around the vegetative nucleus at the binuclear stage and that were identified as amyloplasts. In conclusion, using the Perls/DAB procedure combined to selected mutant genotypes, this study has established a reliable atlas of Fe distribution in the main Arabidopsis organs, proving and refining long-assumed intracellular locations and uncovering new ones. This "iron map" of Arabidopsis will serve as a basis for future studies of possible actors of iron movement in plant tissues and cell compartments.
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Affiliation(s)
| | | | | | | | | | | | - Stéphane Mari
- *Correspondence: Stéphane Mari, Institut National pour le Recherche Agronomique, Laboratoire de Biochimie et Physiologie Moléculaire des Plantes, INRA/SupAgro, place Viala, bâtiment 7, Montpellier, F-34060, France e-mail:
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Roschzttardtz H, Conéjéro G, Divol F, Alcon C, Verdeil JL, Curie C, Mari S. New insights into Fe localization in plant tissues. Front Plant Sci 2013; 4:350. [PMID: 24046774 DOI: 10.3389/fpls201300350] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 08/20/2013] [Indexed: 05/22/2023]
Abstract
Deciphering cellular iron (Fe) homeostasis requires having access to both quantitative and qualitative information on the subcellular pools of Fe in tissues and their dynamics within the cells. We have taken advantage of the Perls/DAB Fe staining procedure to perform a systematic analysis of Fe distribution in roots, leaves and reproductive organs of the model plant Arabidopsis thaliana, using wild-type and mutant genotypes affected in iron transport and storage. Roots of soil-grown plants accumulate iron in the apoplast of the central cylinder, a pattern that is strongly intensified when the citrate effluxer FRD3 is not functional, thus stressing the importance of citrate in the apoplastic movement of Fe. In leaves, Fe level is low and only detected in and around vascular tissues. In contrast, Fe staining in leaves of iron-treated plants extends in the surrounding mesophyll cells where Fe deposits, likely corresponding to Fe-ferritin complexes, accumulate in the chloroplasts. The loss of ferritins in the fer1,3,4 triple mutant provoked a massive accumulation of Fe in the apoplastic space, suggesting that in the absence of iron buffering in the chloroplast, cells activate iron efflux and/or repress iron influx to limit the amount of iron in the cell. In flowers, Perls/DAB staining has revealed a major sink for Fe in the anthers. In particular, developing pollen grains accumulate detectable amounts of Fe in small-size intracellular bodies that aggregate around the vegetative nucleus at the binuclear stage and that were identified as amyloplasts. In conclusion, using the Perls/DAB procedure combined to selected mutant genotypes, this study has established a reliable atlas of Fe distribution in the main Arabidopsis organs, proving and refining long-assumed intracellular locations and uncovering new ones. This "iron map" of Arabidopsis will serve as a basis for future studies of possible actors of iron movement in plant tissues and cell compartments.
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Affiliation(s)
- Hannetz Roschzttardtz
- Biochimie et Physiologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Institut National pour la Recherche Agronomique, Laboratoire de Biochimie et Physiologie Moléculaire des Plantes, INRA/SupAgro,Université Montpellier 2 Montpellier, France
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Roschzttardtz H, Grillet L, Isaure MP, Conéjéro G, Ortega R, Curie C, Mari S. Plant cell nucleolus as a hot spot for iron. J Biol Chem 2011; 286:27863-6. [PMID: 21719700 PMCID: PMC3151030 DOI: 10.1074/jbc.c111.269720] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 06/29/2011] [Indexed: 11/06/2022] Open
Abstract
Many central metabolic processes require iron as a cofactor and take place in specific subcellular compartments such as the mitochondrion or the chloroplast. Proper iron allocation in the different organelles is thus critical to maintain cell function and integrity. To study the dynamics of iron distribution in plant cells, we have sought to identify the different intracellular iron pools by combining three complementary imaging approaches, histochemistry, micro particle-induced x-ray emission, and synchrotron radiation micro X-ray fluorescence. Pea (Pisum sativum) embryo was used as a model in this study because of its large cell size and high iron content. Histochemical staining with ferrocyanide and diaminobenzidine (Perls/diaminobenzidine) strongly labeled a unique structure in each cell, which co-labeled with the DNA fluorescent stain DAPI, thus corresponding to the nucleus. The unexpected presence of iron in the nucleus was confirmed by elemental imaging using micro particle-induced x-ray emission. X-ray fluorescence on cryo-sectioned embryos further established that, quantitatively, the iron concentration found in the nucleus was higher than in the expected iron-rich organelles such as plastids or vacuoles. Moreover, within the nucleus, iron was particularly accumulated in a subcompartment that was identified as the nucleolus as it was shown to transiently disassemble during cell division. Taken together, our data uncover an as yet unidentified although abundant iron pool in the cell, which is located in the nuclei of healthy, actively dividing plant tissues. This result paves the way for the discovery of a novel cellular function for iron related to nucleus/nucleolus-associated processes.
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Affiliation(s)
- Hannetz Roschzttardtz
- From the Laboratoire de Biochimie et Physiologie Moléculaire des Plantes, Institut de Biologie Intégrative des Plantes, Centre National de la Recherche Scientifique (UMR5004), Institut National de la Recherche Agronomique, Ecole Nationale Supérieure d'Agronomie, Université Montpellier II, F-34060 Montpellier Cedex 2
| | - Louis Grillet
- From the Laboratoire de Biochimie et Physiologie Moléculaire des Plantes, Institut de Biologie Intégrative des Plantes, Centre National de la Recherche Scientifique (UMR5004), Institut National de la Recherche Agronomique, Ecole Nationale Supérieure d'Agronomie, Université Montpellier II, F-34060 Montpellier Cedex 2
| | - Marie-Pierre Isaure
- the Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, Institut Pluridisciplinaire de Recherche sur l'Environnement et les Matériaux, Centre National de la Recherche Scientifique (UMR5254), Université de Pau et des Pays de l'Adour, F-64063 Pau Cedex 9, and
| | - Geneviève Conéjéro
- From the Laboratoire de Biochimie et Physiologie Moléculaire des Plantes, Institut de Biologie Intégrative des Plantes, Centre National de la Recherche Scientifique (UMR5004), Institut National de la Recherche Agronomique, Ecole Nationale Supérieure d'Agronomie, Université Montpellier II, F-34060 Montpellier Cedex 2
| | - Richard Ortega
- the Centre d'Etudes Nucléaires de Bordeaux Gradignan, Centre National de la Recherche Scientifique (UMR5797), Université de Bordeaux, F-33175 Gradignan Cedex, France
| | - Catherine Curie
- From the Laboratoire de Biochimie et Physiologie Moléculaire des Plantes, Institut de Biologie Intégrative des Plantes, Centre National de la Recherche Scientifique (UMR5004), Institut National de la Recherche Agronomique, Ecole Nationale Supérieure d'Agronomie, Université Montpellier II, F-34060 Montpellier Cedex 2
| | - Stéphane Mari
- From the Laboratoire de Biochimie et Physiologie Moléculaire des Plantes, Institut de Biologie Intégrative des Plantes, Centre National de la Recherche Scientifique (UMR5004), Institut National de la Recherche Agronomique, Ecole Nationale Supérieure d'Agronomie, Université Montpellier II, F-34060 Montpellier Cedex 2
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Roschzttardtz H, Séguéla-Arnaud M, Briat JF, Vert G, Curie C. The FRD3 citrate effluxer promotes iron nutrition between symplastically disconnected tissues throughout Arabidopsis development. Plant Cell 2011; 23:2725-37. [PMID: 21742986 PMCID: PMC3226209 DOI: 10.1105/tpc.111.088088] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We present data supporting a general role for FERRIC REDICTASE DEFECTIVE3 (FRD3), an efflux transporter of the efficient iron chelator citrate, in maintaining iron homeostasis throughout plant development. In addition to its well-known expression in root, we show that FRD3 is strongly expressed in Arabidopsis thaliana seed and flower. Consistently, frd3 loss-of-function mutants are defective in early germination and are almost completely sterile, both defects being rescued by iron and/or citrate supply. The frd3 fertility defect is caused by pollen abortion and is associated with the male gametophytic expression of FRD3. Iron imaging shows the presence of important deposits of iron on the surface of aborted pollen grains. This points to a role for FRD3 and citrate in proper iron nutrition of embryo and pollen. Based on the findings that iron acquisition in embryo, leaf, and pollen depends on FRD3, we propose that FRD3 mediated-citrate release in the apoplastic space represents an important process by which efficient iron nutrition is achieved between adjacent tissues lacking symplastic connections. These results reveal a physiological role for citrate in the apoplastic transport of iron throughout development, and provide a general model for multicellular organisms in the cell-to-cell transport of iron involving extracellular circulation.
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Roschzttardtz H, Conéjéro G, Curie C, Mari S. Straightforward histochemical staining of Fe by the adaptation of an old-school technique: identification of the endodermal vacuole as the site of Fe storage in Arabidopsis embryos. Plant Signal Behav 2010; 5:56-7. [PMID: 20592810 PMCID: PMC2835959 DOI: 10.4161/psb.5.1.10159] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Accepted: 09/22/2009] [Indexed: 05/20/2023]
Abstract
Iron (Fe) is an essential metal ion, required for basic cellular processes such as respiration, photosynthesis and cell division. Therefore, Fe has to be stored and distributed to several organelles to fulfill its roles. The molecular basis of Fe distribution is poorly understood. In this context, elemental imaging approaches are becoming essential for a better understanding of metal homeostasis in plants. Recently, several genes have been involved in Fe storage (VIT1) and remobilization (NRAMP3 and NRAMP4) in the seed of Arabidopsis, mostly with the help of sophisticated imaging techniques. We have adapted an histochemical procedure to detect Fe in plant tissues, based on Perls staining coupled to diaminobenzidine (DAB) intensification. The Perls/DAB technique, quick and inexpensive, was shown to be specific for Fe and highly sensitive. We have applied this procedure to Arabidopsis embryos and shown that Fe is stored in the vacuoles of a specific cell layer surrounding the pro-vascular system, the endodermis. Our results have revealed a new role for the endodermis in Fe storage in the embryo and established the Perls/DAB technique as a powerful tool to detect Fe in plant tissues and cells.
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Affiliation(s)
- Hannetz Roschzttardtz
- Institut de Biologie Intégrative des Plantes, Centre National de la Recherche Scientifique (UMR5004), Université Montpellier II, Ecole Nationale Supérieure d'Agronomie, Montpellier, France
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Roschzttardtz H, Conéjéro G, Curie C, Mari S. Identification of the endodermal vacuole as the iron storage compartment in the Arabidopsis embryo. Plant Physiol 2009; 151:1329-38. [PMID: 19726572 PMCID: PMC2773051 DOI: 10.1104/pp.109.144444] [Citation(s) in RCA: 155] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Accepted: 08/28/2009] [Indexed: 05/17/2023]
Abstract
Deciphering how cellular iron (Fe) pools are formed, where they are localized, and which ones are remobilized represents an important challenge to better understand Fe homeostasis. The recent development of imaging techniques, adapted to plants, has helped gain insight into these events. We have analyzed the localization of Fe during embryo development in Arabidopsis (Arabidopsis thaliana) with an improved histochemical staining based on Perls coloration intensified by a second reaction with diaminobenzidine and hydrogen peroxide. The procedure, quick to set up and specific for Fe, was applied directly on histological sections, which dramatically increased its subcellular resolution. We have thus unambiguously shown that in dry seeds Fe is primarily stored in the endodermis cell layer, within the vacuoles, from which it is remobilized during germination. In the vit1-1 mutant, in which the Fe pattern is disturbed, Fe is stored in vacuoles of cortex cells of the hypocotyl/radicle axis and in a single subepidermal cell layer in the cotyledons. During the early stages of embryo development, Fe is evenly distributed in the cells of both wild-type and vit1-1 mutants. Fe eventually accumulates in endodermal cells as the vascular system develops, a process that is impaired in vit1-1. Our results have uncovered a new role for the endodermis in Fe storage in the embryo and have established that the Perls/diaminobenzidine staining is a method of choice to detect Fe in plant tissues and cells.
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Roschzttardtz H, Fuentes I, Vásquez M, Corvalán C, León G, Gómez I, Araya A, Holuigue L, Vicente-Carbajosa J, Jordana X. A nuclear gene encoding the iron-sulfur subunit of mitochondrial complex II is regulated by B3 domain transcription factors during seed development in Arabidopsis. Plant Physiol 2009; 150:84-95. [PMID: 19261733 PMCID: PMC2675723 DOI: 10.1104/pp.109.136531] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Accepted: 02/17/2009] [Indexed: 05/20/2023]
Abstract
Mitochondrial complex II (succinate dehydrogenase) is part of the tricarboxylic acid cycle and the respiratory chain. Three nuclear genes encode its essential iron-sulfur subunit in Arabidopsis (Arabidopsis thaliana). One of them, SUCCINATE DEHYDROGENASE2-3 (SDH2-3), is specifically expressed in the embryo during seed maturation, suggesting that SDH2-3 may have a role as the complex II iron-sulfur subunit during embryo maturation and/or germination. Here, we present data demonstrating that three abscisic acid-responsive elements and one RY-like enhancer element, present in the SDH2-3 promoter, are involved in embryo-specific SDH2-3 transcriptional regulation. Furthermore, we show that ABSCISIC ACID INSENSITIVE3 (ABI3), FUSCA3 (FUS3), and LEAFY COTYLEDON2, three key B3 domain transcription factors involved in gene expression during seed maturation, control SDH2-3 expression. Whereas ABI3 and FUS3 interact with the RY element in the SDH2-3 promoter, the abscisic acid-responsive elements are shown to be a target for bZIP53, a member of the basic leucine zipper (bZIP) family of transcription factors. We show that group S1 bZIP53 protein binds the promoter as a heterodimer with group C bZIP10 or bZIP25. To the best of our knowledge, the SDH2-3 promoter is the first embryo-specific promoter characterized for a mitochondrial respiratory complex protein. Characterization of succinate dehydrogenase activity in embryos from two homozygous sdh2-3 mutant lines permits us to conclude that SDH2-3 is the major iron-sulfur subunit of mature embryo complex II. Finally, the absence of SDH2-3 in mutant seeds slows down their germination, pointing to a role of SDH2-3-containing complex II at an early step of germination.
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Affiliation(s)
- Hannetz Roschzttardtz
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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Elorza A, Roschzttardtz H, Gómez I, Mouras A, Holuigue L, Araya A, Jordana X. A nuclear gene for the iron-sulfur subunit of mitochondrial complex II is specifically expressed during Arabidopsis seed development and germination. Plant Cell Physiol 2006; 47:14-21. [PMID: 16249327 DOI: 10.1093/pcp/pci218] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Three nuclear genes, SDH2-1, SDH2-2 and SDH2-3, encode the essential iron-sulfur subunit of mitochondrial complex II in Arabidopsis thaliana. SDH2-1 and SDH2-2 probably arose via a recent duplication event and we reported that both are expressed in all organs from adult plants. In contrast, transcripts from SDH2-3 were not detected. Here we present data demonstrating that SDH2-3 is specifically expressed during seed development. SDH2-3 transcripts appear during seed maturation, persist through desiccation, are abundant in dry seeds and markedly decline during germination. Analysis of transgenic Arabidopsis plants carrying the SDH2-3 promoter fused to the beta-glucuronidase reporter gene shows that the SDH2-3 promoter is activated in the embryo during maturation, from the bent-cotyledon stage. beta-Glucuronidase expression correlates with the appearance of endogenous SDH2-3 transcripts, suggesting that control of this nuclear gene is achieved through transcriptional regulation. Furthermore, progressive deletions of this promoter identified a 159 bp region (-223 to -65) important for SDH2-3 transcriptional activation in seeds. Interestingly, the SDH2-3 promoter remains active in embryonic tissues during germination and post-germinative growth, and is turned off in vegetative tissues (true leaves). In contrast to SDH2-3 transcripts, SDH2-1 and SDH2-2 transcripts are barely detected in dry seeds and increase during germination and post-germinative growth. The opposite expression patterns of SDH2 nuclear genes strongly suggest that during germination the embryo-specific SDH2-3 is replaced by SDH2-1 or SDH2-2 in mitochondrial complex II.
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Affiliation(s)
- Alvaro Elorza
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Casilla 114-D, Santiago
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Krautwurst H, Roschzttardtz H, Bazaes S, González-Nilo FD, Nowak T, Cardemil E. Lysine 213 and histidine 233 participate in Mn(II) binding and catalysis in Saccharomyces cerevisiae phosphoenolpyruvate carboxykinase. Biochemistry 2002; 41:12763-70. [PMID: 12379119 DOI: 10.1021/bi026241w] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Saccharomyces cerevisiae phosphoenolpyruvate (PEP) carboxykinase catalyses the reversible metal-dependent formation of oxaloacetate and ATP from PEP, ADP, and CO2 and plays a key role in gluconeogenesis. This enzyme also has oxaloacetate decarboxylase and pyruvate kinase-like activities. Mutations of PEP carboxykinase have been constructed where the residues Lys213 and His233, two residues of the putative Mn2+ binding site of the enzyme, were altered. Replacement of these residues by Arg and by Gln, respectively, generated enzymes with 1.9 and 2.8 kcal/mol lower Mn2+ binding affinity. Lower PEP binding affinity was inferred for the mutated enzymes from the protection effect of PEP against urea denaturation. Kinetic studies of the altered enzymes show at least a 5000-fold reduction in V(max) for the primary reaction relative to that for the wild-type enzyme. V(max) values for the oxaloacetate decarboxylase and pyruvate kinase-like activities of PEP carboxykinase were affected to a much lesser extent in the mutated enzymes. The mutated enzymes show a decreased steady-state affinity for Mn2+ and PEP. The results are consistent with Lys213 and His233 being at the Mn2+ binding site of S. cerevisiae PEP carboxykinase and the Mn2+ affecting the PEP interaction. The different effects of mutations in V(max) for the main reaction and the secondary activities suggest different rate-limiting steps for these reactions.
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Affiliation(s)
- Hans Krautwurst
- Departamento de Ciencias Químicas, Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, Santiago 33, Chile
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