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Slocombe SP, Zúñiga-Burgos T, Chu L, Mehrshahi P, Davey MP, Smith AG, Camargo-Valero MA, Baker A. Overexpression of PSR1 in Chlamydomonas reinhardtii induces luxury phosphorus uptake. FRONTIERS IN PLANT SCIENCE 2023; 14:1208168. [PMID: 37575910 PMCID: PMC10413257 DOI: 10.3389/fpls.2023.1208168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 05/23/2023] [Indexed: 08/15/2023]
Abstract
Remediation using micro-algae offers an attractive solution to environmental phosphate (PO4 3-) pollution. However, for maximum efficiency, pre-conditioning of algae to induce 'luxury phosphorus (P) uptake' is needed. To replicate this process, we targeted the global regulator PSR1 (Myb transcription factor: Phosphate Starvation Response 1) for over-expression in algae. Manipulating a single gene (PSR1) drove uptake of both PO4 3- and a Mg2+ counter-ion leading to increased PolyP granule size, raising P levels 4-fold to 8% dry cell weight, and accelerated removal of PO4 3- from the medium. Examination of the gene expression profile showed that the P-starvation response was mimicked under P-replete conditions, switching on luxury uptake. Hyper-accumulation of P depended on a feed-forward mechanism, where a small set of 'Class I' P-transporter genes were activated despite abundant external PO4 3- levels. The transporters drove a reduction in external PO4 3- levels, permitting more genes to be expressed (Class II), leading to more P-uptake. Our data pointed toward a PSR1-independent mechanism for detection of external PO4 3- which suppressed Class II genes. This model provided a plausible mechanism for P-overplus where prior P-starvation elevates PSR1 and on P-resupply causes luxury P-uptake. This is because the Class I genes, which include P-transporter genes, are not suppressed by the excess PO4 3-. Taken together, these discoveries facilitate a bio-circular approach of recycling nutrients from wastewater back to agriculture.
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Affiliation(s)
- Stephen P. Slocombe
- School of Molecular and Cellular Biology, Centre for Plant Sciences and Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Tatiana Zúñiga-Burgos
- School of Molecular and Cellular Biology, Centre for Plant Sciences and Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
- BioResource Systems Research Group, School of Civil Engineering, University of Leeds, Leeds, United Kingdom
| | - Lili Chu
- School of Molecular and Cellular Biology, Centre for Plant Sciences and Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Payam Mehrshahi
- Department of Plant Sciences, Cambridge University, Cambridge, United Kingdom
| | - Matthew P. Davey
- Department of Plant Sciences, Cambridge University, Cambridge, United Kingdom
| | - Alison G. Smith
- Department of Plant Sciences, Cambridge University, Cambridge, United Kingdom
| | - Miller Alonso Camargo-Valero
- BioResource Systems Research Group, School of Civil Engineering, University of Leeds, Leeds, United Kingdom
- Departamento de Ingeniería Química, Universidad Nacional de Colombia, Manizales, Colombia
| | - Alison Baker
- School of Molecular and Cellular Biology, Centre for Plant Sciences and Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
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Grinko A, Alqoubaili R, Lapina T, Ermilova E. Truncated hemoglobin 2 modulates phosphorus deficiency response by controlling of gene expression in nitric oxide-dependent pathway in Chlamydomonas reinhardtii. PLANTA 2021; 254:39. [PMID: 34319485 DOI: 10.1007/s00425-021-03691-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 07/19/2021] [Indexed: 06/13/2023]
Abstract
Truncated hemoglobin 2 is involved in fine-tuning of PSR1-regulated gene expression during phosphorus deprivation. Truncated hemoglobins form a large family found in all domains of life. However, a majority of physiological functions of these proteins remain to be elucidated. In the model alga Chlamydomonas reinhardtii, macro-nutritional deprivation is known to elevate truncated hemoglobin 2 (THB2). This study investigated the role of THB2 in the regulation of a subset of phosphorus (P) limitation-responsive genes in cells suffering from P-deficiency. Underexpression of THB2 in amiTHB2 strains resulted in downregulation of a suite of P deprivation-induced genes encoding proteins with different subcellular location and functions (e.g., PHOX, LHCSR3.1, LHCSR3.2, PTB2, and PTB5). Moreover, our results provided primary evidence that the soluble guanylate cyclase 12 gene (CYG12) is a component of the P deprivation regulation. Furthermore, the transcription of PSR1 gene for the most critical regulator in the acclimation process under P restriction was repressed by nitric oxide (NO). Collectively, the results indicated a tight regulatory link between the THB2-controlled NO levels and PSR1-dependent induction of several P deprivation responsive genes with various roles in cells during P-limitation.
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Affiliation(s)
- Alexandra Grinko
- Biological Faculty, Saint-Petersburg State University, Saint-Petersburg, 199034, Russia
| | - Reem Alqoubaili
- Biological Faculty, Saint-Petersburg State University, Saint-Petersburg, 199034, Russia
| | - Tatiana Lapina
- Biological Faculty, Saint-Petersburg State University, Saint-Petersburg, 199034, Russia
| | - Elena Ermilova
- Biological Faculty, Saint-Petersburg State University, Saint-Petersburg, 199034, Russia.
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Control of distal lysine coordination in a monomeric hemoglobin: A role for heme peripheral interactions. J Inorg Biochem 2021; 219:111437. [PMID: 33892380 DOI: 10.1016/j.jinorgbio.2021.111437] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 03/20/2021] [Accepted: 03/20/2021] [Indexed: 12/25/2022]
Abstract
THB1 is a monomeric truncated hemoglobin (TrHb) found in the cytoplasm of the green alga Chlamydomonas reinhardtii. The canonical heme coordination scheme in hemoglobins is a proximal histidine ligand and an open distal site. In THB1, the latter site is occupied by Lys53, which is likely to facilitate Fe(II)/Fe(III) redox cycling but hinders dioxygen binding, two features inherent to the NO dioxygenase activity of the protein. TrHb surveys show that a lysine at a position aligning with Lys53 is an insufficient determinant of coordination, and in this study, we sought to identify factors controlling lysine affinity for the heme iron. We solved the "Lys-off" X-ray structure of THB1, represented by the cyanide adduct of the Fe(III) protein, and hypothesized that interactions that differ between the known "Lys-on" structure and the Lys-off structure participate in the control of Lys53 affinity for the heme iron. We applied an experimental approach (site-directed mutagenesis, heme modification, pH titrations in the Fe(III) and Fe(II) states) and a computational approach (MD simulations in the Fe(II) state) to assess the role of heme propionate-protein interactions, distal helix capping, and the composition of the distal pocket. All THB1 modifications resulted in a weakening of lysine affinity and affected the coupling between Lys53 proton binding and heme redox potential. The results supported the importance of specific heme peripheral interactions for the pH stability of iron coordination and the ability of the protein to undergo redox reactions.
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Astier J, Rossi J, Chatelain P, Klinguer A, Besson-Bard A, Rosnoblet C, Jeandroz S, Nicolas-Francès V, Wendehenne D. Nitric oxide production and signalling in algae. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:781-792. [PMID: 32910824 DOI: 10.1093/jxb/eraa421] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 09/07/2020] [Indexed: 05/27/2023]
Abstract
Nitric oxide (NO) was the first identified gaseous messenger and is now well established as a major ubiquitous signalling molecule. The rapid development of our understanding of NO biology in embryophytes came with the partial characterization of the pathways underlying its production and with the decrypting of signalling networks mediating its effects. Notably, the identification of proteins regulated by NO through nitrosation greatly enhanced our perception of NO functions. In comparison, the role of NO in algae has been less investigated. Yet, studies in Chlamydomonas reinhardtii have produced key insights into NO production through the identification of NO-forming nitrite reductase and of S-nitrosated proteins. More intriguingly, in contrast to embryophytes, a few algal species possess a conserved nitric oxide synthase, the main enzyme catalysing NO synthesis in metazoans. This latter finding paves the way for a deeper characterization of novel members of the NO synthase family. Nevertheless, the typical NO-cyclic GMP signalling module transducing NO effects in metazoans is not conserved in algae, nor in embryophytes, highlighting a divergent acquisition of NO signalling between the green and the animal lineages.
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Affiliation(s)
- Jeremy Astier
- Agroécologie, AgroSup Dijon, CNRS, INRAE, Univ. Bourgogne Franche-Comté, Dijon, France
| | - Jordan Rossi
- Agroécologie, AgroSup Dijon, CNRS, INRAE, Univ. Bourgogne Franche-Comté, Dijon, France
| | - Pauline Chatelain
- Agroécologie, AgroSup Dijon, CNRS, INRAE, Univ. Bourgogne Franche-Comté, Dijon, France
| | - Agnès Klinguer
- Agroécologie, AgroSup Dijon, CNRS, INRAE, Univ. Bourgogne Franche-Comté, Dijon, France
| | - Angélique Besson-Bard
- Agroécologie, AgroSup Dijon, CNRS, INRAE, Univ. Bourgogne Franche-Comté, Dijon, France
| | - Claire Rosnoblet
- Agroécologie, AgroSup Dijon, CNRS, INRAE, Univ. Bourgogne Franche-Comté, Dijon, France
| | - Sylvain Jeandroz
- Agroécologie, AgroSup Dijon, CNRS, INRAE, Univ. Bourgogne Franche-Comté, Dijon, France
| | | | - David Wendehenne
- Agroécologie, AgroSup Dijon, CNRS, INRAE, Univ. Bourgogne Franche-Comté, Dijon, France
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Burlacot A, Burlacot F, Li-Beisson Y, Peltier G. Membrane Inlet Mass Spectrometry: A Powerful Tool for Algal Research. FRONTIERS IN PLANT SCIENCE 2020; 11:1302. [PMID: 33013952 PMCID: PMC7500362 DOI: 10.3389/fpls.2020.01302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 08/11/2020] [Indexed: 05/15/2023]
Abstract
Since the first great oxygenation event, photosynthetic microorganisms have continuously shaped the Earth's atmosphere. Studying biological mechanisms involved in the interaction between microalgae and cyanobacteria with the Earth's atmosphere requires the monitoring of gas exchange. Membrane inlet mass spectrometry (MIMS) has been developed in the early 1960s to study gas exchange mechanisms of photosynthetic cells. It has since played an important role in investigating various cellular processes that involve gaseous compounds (O2, CO2, NO, or H2) and in characterizing enzymatic activities in vitro or in vivo. With the development of affordable mass spectrometers, MIMS is gaining wide popularity and is now used by an increasing number of laboratories. However, it still requires an important theory and practical considerations to be used. Here, we provide a practical guide describing the current technical basis of a MIMS setup and the general principles of data processing. We further review how MIMS can be used to study various aspects of algal research and discuss how MIMS will be useful in addressing future scientific challenges.
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Ermilova E. Cold Stress Response: An Overview in Chlamydomonas. FRONTIERS IN PLANT SCIENCE 2020; 11:569437. [PMID: 33013991 PMCID: PMC7494811 DOI: 10.3389/fpls.2020.569437] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 08/18/2020] [Indexed: 06/01/2023]
Abstract
Low temperature (or cold) is one of the major environmental factors that limit the growth and development of many plants. Various plant species have evolved complex mechanisms to adjust to decreased temperature. Mesophilic chlorophytes are a widely distributed group of eukaryotic photosynthetic organisms, but there is insufficient information about the key molecular processes of their cold acclimation. The best available model for studying how chlorophytes respond to and cope with variations in temperature is the unicellular green alga Chlamydomonas reinhardtii. Chlamydomonas has been widely used for decades as a model system for studying the fundamental mechanisms of the plant heat stress response. At present, unraveling novel cold-regulated events in Chlamydomonas has attracted increasing research attention. This mini-review summarizes recent progress on low-temperature-dependent processes in the model alga, while information on other photosynthetic organisms (cyanobacteria and land plants) was used to strengthen generalizations or specializations of cold-induced mechanisms in plant evolution. Here, we describe recent advances in our understanding of cold stress response in Chlamydomonas, discuss areas of controversy, and highlight potential future directions in cold acclimation research.
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Abstract
Nitrous oxide (N2O), the third most important greenhouse gas in the atmosphere, is produced in great quantities by microalgae, but molecular mechanisms remain elusive. Here we show that the green microalga Chlamydomonas reinhardtii produces N2O in the light by a reduction of NO driven by photosynthesis and catalyzed by flavodiiron proteins, the dark N2O production being catalyzed by a cytochrome p450. Both mechanisms of N2O production are present in chlorophytes, but absent from diatoms. Our study provides an unprecedented mechanistic understanding of N2O production by microalgae, allowing a better assessment of N2O-producing hot spots in aquatic environments. Nitrous oxide (N2O), a potent greenhouse gas in the atmosphere, is produced mostly from aquatic ecosystems, to which algae substantially contribute. However, mechanisms of N2O production by photosynthetic organisms are poorly described. Here we show that the green microalga Chlamydomonas reinhardtii reduces NO into N2O using the photosynthetic electron transport. Through the study of C. reinhardtii mutants deficient in flavodiiron proteins (FLVs) or in a cytochrome p450 (CYP55), we show that FLVs contribute to NO reduction in the light, while CYP55 operates in the dark. Both pathways are active when NO is produced in vivo during the reduction of nitrites and participate in NO homeostasis. Furthermore, NO reduction by both pathways is restricted to chlorophytes, organisms particularly abundant in ocean N2O-producing hot spots. Our results provide a mechanistic understanding of N2O production in eukaryotic phototrophs and represent an important step toward a comprehensive assessment of greenhouse gas emission by aquatic ecosystems.
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Thornburg TE, Liu J, Li Q, Xue H, Wang G, Li L, Fontana JE, Davis KE, Liu W, Zhang B, Zhang Z, Liu M, Pan X. Potassium Deficiency Significantly Affected Plant Growth and Development as Well as microRNA-Mediated Mechanism in Wheat ( Triticum aestivum L.). FRONTIERS IN PLANT SCIENCE 2020; 11:1219. [PMID: 32922417 PMCID: PMC7456879 DOI: 10.3389/fpls.2020.01219] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 07/27/2020] [Indexed: 05/08/2023]
Abstract
It is well studied that potassium (K+) deficiency induced aberrant growth and development of plant and altered the expression of protein-coding genes. However, there are not too many systematic investigations on root development affected by K+ deficiency, and there is no report on miRNA expression during K+ deficiency in wheat. In this study, we found that K+ deficiency significantly affected wheat seedling growth and development, evidenced by reduced plant biomass and small plant size. In wheat cultivar AK-58, up-ground shoots were more sensitive to K+ deficiency than roots. K+ deficiency did not significantly affect root vitality but affected root development, including root branching, root area, and root size. K+ deficiency delayed seminal root emergence but enhanced seminal root elongation, total root length, and correspondingly total root surface area. K+ deficiency also affected root and leaf respiration at the early exposure stage, but these effects were not observed at the later stage. One potential mechanism causing K+ deficiency impacts is microRNAs (miRNAs), one important class of small regulatory RNAs. K+ deficiency induced the aberrant expression of miRNAs and their targets, which further affected plant growth, development, and response to abiotic stresses, including K+ deficiency. Thereby, this positive root adaption to K+ deficiency is likely associated with the miRNA-involved regulation of root development.
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Affiliation(s)
- Thomas Elliott Thornburg
- Henan Collaborative Innovation Center of Modern Biological Breeding and Henan Key Laboratory for Molecular Ecology and Germplasm Innovation of Cotton and Wheat, Henan Institute of Science and Technology, Xinxiang, China
- Department of Biology, East Carolina University, Greenville, NC, United States
| | - Jia Liu
- Henan Collaborative Innovation Center of Modern Biological Breeding and Henan Key Laboratory for Molecular Ecology and Germplasm Innovation of Cotton and Wheat, Henan Institute of Science and Technology, Xinxiang, China
| | - Qian Li
- Henan Collaborative Innovation Center of Modern Biological Breeding and Henan Key Laboratory for Molecular Ecology and Germplasm Innovation of Cotton and Wheat, Henan Institute of Science and Technology, Xinxiang, China
| | - Huiyun Xue
- Henan Collaborative Innovation Center of Modern Biological Breeding and Henan Key Laboratory for Molecular Ecology and Germplasm Innovation of Cotton and Wheat, Henan Institute of Science and Technology, Xinxiang, China
| | - Guo Wang
- Henan Collaborative Innovation Center of Modern Biological Breeding and Henan Key Laboratory for Molecular Ecology and Germplasm Innovation of Cotton and Wheat, Henan Institute of Science and Technology, Xinxiang, China
| | - Lijie Li
- Henan Collaborative Innovation Center of Modern Biological Breeding and Henan Key Laboratory for Molecular Ecology and Germplasm Innovation of Cotton and Wheat, Henan Institute of Science and Technology, Xinxiang, China
| | - Julia Elise Fontana
- Henan Collaborative Innovation Center of Modern Biological Breeding and Henan Key Laboratory for Molecular Ecology and Germplasm Innovation of Cotton and Wheat, Henan Institute of Science and Technology, Xinxiang, China
- Department of Biology, East Carolina University, Greenville, NC, United States
| | - Kyle E. Davis
- Henan Collaborative Innovation Center of Modern Biological Breeding and Henan Key Laboratory for Molecular Ecology and Germplasm Innovation of Cotton and Wheat, Henan Institute of Science and Technology, Xinxiang, China
- Department of Biology, East Carolina University, Greenville, NC, United States
| | - Wanying Liu
- College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Baohong Zhang
- Department of Biology, East Carolina University, Greenville, NC, United States
| | - Zhiyong Zhang
- Henan Collaborative Innovation Center of Modern Biological Breeding and Henan Key Laboratory for Molecular Ecology and Germplasm Innovation of Cotton and Wheat, Henan Institute of Science and Technology, Xinxiang, China
- *Correspondence: Zhiyong Zhang, ; Mingjiu Liu, ; Xiaoping Pan,
| | - Mingjiu Liu
- Henan Collaborative Innovation Center of Modern Biological Breeding and Henan Key Laboratory for Molecular Ecology and Germplasm Innovation of Cotton and Wheat, Henan Institute of Science and Technology, Xinxiang, China
- *Correspondence: Zhiyong Zhang, ; Mingjiu Liu, ; Xiaoping Pan,
| | - Xiaoping Pan
- Department of Biology, East Carolina University, Greenville, NC, United States
- *Correspondence: Zhiyong Zhang, ; Mingjiu Liu, ; Xiaoping Pan,
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