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Hounslow E, Evans CA, Pandhal J, Sydney T, Couto N, Pham TK, Gilmour DJ, Wright PC. Quantitative proteomic comparison of salt stress in Chlamydomonas reinhardtii and the snow alga Chlamydomonas nivalis reveals mechanisms for salt-triggered fatty acid accumulation via reallocation of carbon resources. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:121. [PMID: 34022944 PMCID: PMC8141184 DOI: 10.1186/s13068-021-01970-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 05/13/2021] [Indexed: 06/01/2023]
Abstract
BACKGROUND Chlamydomonas reinhardtii is a model green alga strain for molecular studies; its fully sequenced genome has enabled omic-based analyses that have been applied to better understand its metabolic responses to stress. Here, we characterised physiological and proteomic changes between a low-starch C. reinhardtii strain and the snow alga Chlamydomonas nivalis, to reveal insights into their contrasting responses to salinity stress. RESULTS Each strain was grown in conditions tailored to their growth requirements to encourage maximal fatty acid (as a proxy measure of lipid) production, with internal controls to allow comparison points. In 0.2 M NaCl, C. nivalis accumulates carbohydrates up to 10.4% DCW at 80 h, and fatty acids up to 52.0% dry cell weight (DCW) over 12 days, however, C. reinhardtii does not show fatty acid accumulation over time, and shows limited carbohydrate accumulation up to 5.5% DCW. Analysis of the C. nivalis fatty acid profiles showed that salt stress improved the biofuel qualities over time. Photosynthesis and respiration rates are reduced in C. reinhardtii relative to C. nivalis in response to 0.2 M NaCl. De novo sequencing and homology matching was used in conjunction with iTRAQ-based quantitative analysis to identify and relatively quantify proteomic alterations in cells exposed to salt stress. There were abundance differences in proteins associated with stress, photosynthesis, carbohydrate and lipid metabolism proteins. In terms of lipid synthesis, salt stress induced an increase in dihydrolipoyl dehydrogenase in C. nivalis (1.1-fold change), whilst levels in C. reinhardtii remained unaffected; this enzyme is involved in acetyl CoA production and has been linked to TAG accumulation in microalgae. In salt-stressed C. nivalis there were decreases in the abundance of UDP-sulfoquinovose (- 1.77-fold change), which is involved in sulfoquinovosyl diacylglycerol metabolism, and in citrate synthase (- 2.7-fold change), also involved in the TCA cycle. Decreases in these enzymes have been shown to lead to increased TAG production as fatty acid biosynthesis is favoured. Data are available via ProteomeXchange with identifier PXD018148. CONCLUSIONS These differences in protein abundance have given greater understanding of the mechanism by which salt stress promotes fatty acid accumulation in the un-sequenced microalga C. nivalis as it switches to a non-growth state, whereas C. reinhardtii does not have this response.
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Affiliation(s)
- E Hounslow
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK
| | - C A Evans
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK.
| | - J Pandhal
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK
| | - T Sydney
- Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK
| | - N Couto
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK
| | - T K Pham
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK
| | - D James Gilmour
- Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - P C Wright
- University of Southampton, University Road, Southampton, SO17 1BJ, UK
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Jensen EL, Maberly SC, Gontero B. Insights on the Functions and Ecophysiological Relevance of the Diverse Carbonic Anhydrases in Microalgae. Int J Mol Sci 2020; 21:E2922. [PMID: 32331234 PMCID: PMC7215798 DOI: 10.3390/ijms21082922] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/19/2020] [Accepted: 04/20/2020] [Indexed: 01/07/2023] Open
Abstract
Carbonic anhydrases (CAs) exist in all kingdoms of life. They are metalloenzymes, often containing zinc, that catalyze the interconversion of bicarbonate and carbon dioxide-a ubiquitous reaction involved in a variety of cellular processes. So far, eight classes of apparently evolutionary unrelated CAs that are present in a large diversity of living organisms have been described. In this review, we focus on the diversity of CAs and their roles in photosynthetic microalgae. We describe their essential role in carbon dioxide-concentrating mechanisms and photosynthesis, their regulation, as well as their less studied roles in non-photosynthetic processes. We also discuss the presence in some microalgae, especially diatoms, of cambialistic CAs (i.e., CAs that can replace Zn by Co, Cd, or Fe) and, more recently, a CA that uses Mn as a metal cofactor, with potential ecological relevance in aquatic environments where trace metal concentrations are low. There has been a recent explosion of knowledge about this well-known enzyme with exciting future opportunities to answer outstanding questions using a range of different approaches.
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Affiliation(s)
- Erik L. Jensen
- Aix Marseille Univ, CNRS, BIP, UMR 7281, IMM, FR3479, 31 Chemin J. Aiguier, CEDEX 20, 13 402 Marseille, France;
| | - Stephen C. Maberly
- UK Centre for Ecology & Hydrology, Lake Ecosystems Group, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP, UK;
| | - Brigitte Gontero
- Aix Marseille Univ, CNRS, BIP, UMR 7281, IMM, FR3479, 31 Chemin J. Aiguier, CEDEX 20, 13 402 Marseille, France;
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Kugler A, Zorin B, Didi-Cohen S, Sibiryak M, Gorelova O, Ismagulova T, Kokabi K, Kumari P, Lukyanov A, Boussiba S, Solovchenko A, Khozin-Goldberg I. Long-Chain Polyunsaturated Fatty Acids in the Green Microalga Lobosphaera incisa Contribute to Tolerance to Abiotic Stresses. PLANT & CELL PHYSIOLOGY 2019; 60:1205-1223. [PMID: 30668793 DOI: 10.1093/pcp/pcz013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 01/15/2019] [Indexed: 05/16/2023]
Abstract
Lobosphaera incisa is a green microalga that accumulates high levels of the valuable omega-6 long-chain polyunsaturated fatty acids (LC-PUFA) arachidonic acid (ARA, 20:4n-6) in triacylglycerols (TAG) under nitrogen (N) starvation. LC-PUFA accumulation is a rare trait in photosynthetic microalgae with insufficiently understood physiological significance. In this study, RNAi was attempted, for the first time in L. incisa, to produce knockdown lines for the Δ5 desaturase gene. Two lines, termed modified lines, which were isolated during screening for transgenic events, demonstrated alterations in their LC-PUFA profile, ARA-biosynthesis gene expression and lipid class distribution. In line M5-78, which appeared to carry a mutation in the Δ6 elongase gene, LC-PUFA were substituted by 18:3n-6 in all glycerolipids. Line M2-35, for which the exact genetic background has not been established, displayed a dramatic reduction in 20:4n-6, concomitant with an augmented proportion of 18:1n-9, in particular in the extraplastidial membrane lipids and TAG. The physiological responses of the modified lines to stressful conditions were compared with the wild type and the Δ5 desaturase mutant. In the N-replete cells of modified lines, the frequency of lipid droplets was reduced, while a number of starch grains increased, suggesting altered partitioning of assimilated carbon into reserve products. Furthermore, both lines exhibited reduced ability to accumulate TAG under N deprivation and recover from N starvation. Both lines demonstrated lower photosynthetic pigment contents, impairments in photosynthesis under a range of stressful conditions, and less efficient functioning of photoprotection under optimal conditions. Possible implications of fatty acids modifications in the stress response of L. incisa are addressed.
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Affiliation(s)
- Amit Kugler
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Boris Zorin
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Shoshana Didi-Cohen
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Maria Sibiryak
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Olga Gorelova
- Faculty of Biology, Department of Bioengineering, Moscow State University, GSP-1, Moscow, Russia
| | - Tatiana Ismagulova
- Faculty of Biology, Department of Bioengineering, Moscow State University, GSP-1, Moscow, Russia
| | - Kamilya Kokabi
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Puja Kumari
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Alexander Lukyanov
- Faculty of Biology, Department of Bioengineering, Moscow State University, GSP-1, Moscow, Russia
| | - Sammy Boussiba
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Alexei Solovchenko
- Faculty of Biology, Department of Bioengineering, Moscow State University, GSP-1, Moscow, Russia
- Institute of Agriculture and Technology, Peoples Friendship University of Russia (RUDN University), Moscow, Russia
| | - Inna Khozin-Goldberg
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
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Spijkerman E, Lukas M, Wacker A. Ecophysiological strategies for growth under varying light and organic carbon supply in two species of green microalgae differing in their motility. PHYTOCHEMISTRY 2017; 144:43-51. [PMID: 28881198 DOI: 10.1016/j.phytochem.2017.08.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 08/26/2017] [Accepted: 08/29/2017] [Indexed: 06/07/2023]
Abstract
Mixing events in stratified lakes result in microalgae being exposed to varying conditions in light and organic carbon concentrations. Stratified lakes consist of an upper illuminated strata and a lower, darker strata where organic carbon accumulates. Therefore, in this contribution we explore the importance of dissolved organic carbon for growth under various light intensities by measuring some ecophysiological adaptations in two green microalgae. We compared the non-motile Chlorella vulgaris with the flagellated Chlamydomonas acidophila under auto-, mixo-, and heterotrophic growth conditions. In both algae the maximum photosynthetic and growth rates were highest under mixotrophy, and both algae appeared inhibited in their phosphorus acquisition under heterotrophy. Heterotrophic conditions provoked the largest differences as C. vulgaris produced chlorophyll a in darkness and grew as well as in autotrophic conditions, whereas Chl. acidophila bleached and could not grow heterotrophically. Although the fatty acid composition of both phytoplankton species differed, both species reacted in a similar way to changes in their growth conditions, mainly by a decrease of C18:3n-3 and an increase of C18:1n-9 from auto- to heterotrophic conditions. The two contrasting responses within the group of green microalgae suggest that dissolved organic carbon has a high deterministic potential to explain the survival and behaviour of green algae in the deeper strata of lakes.
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Affiliation(s)
- Elly Spijkerman
- University of Potsdam, Dept. of Ecology and Ecosystem Modelling, Maulbeerallee 2, 14469 Potsdam, Germany.
| | - Marcus Lukas
- University of Potsdam, Dept. of Ecology and Ecosystem Modelling, Maulbeerallee 2, 14469 Potsdam, Germany
| | - Alexander Wacker
- University of Potsdam, Dept. of Theoretical Aquatic Ecology and Ecophysiology, Maulbeerallee 2, 14469 Potsdam, Germany
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Cañavate JP, Armada I, Hachero-Cruzado I. Common and Species-Specific Effects of Phosphate on Marine Microalgae Fatty Acids Shape Their Function in Phytoplankton Trophic Ecology. MICROBIAL ECOLOGY 2017; 74:623-639. [PMID: 28411302 DOI: 10.1007/s00248-017-0983-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 04/10/2017] [Indexed: 05/08/2023]
Abstract
The use of fatty acids (FA) to infer structure of phytoplankton assemblages and as indicators of microalgae nutritional value is acquiring relevance in modern phytoplankton ecology and new advances concerning factors influencing FA variability among microalgae are demanded. In this regard, the relationship between phosphorus and FA remains particularly little studied in marine phytoplankton. In the present study, we focus on phosphate effects on FA from a diversified set of marine microalgae and provide new insights into the applicability of FA in phytoplankton trophic ecology. Phosphate deprivation mainly induced monounsaturated FA production in eight out of nine microalgae and their changes were species-specific, with palmitoleic acid exhibiting extreme variation and discriminating between haptophyte classes. The important phosphate-induced and interspecific variability found for oleic acid was perceived as a concern for the current application of this FA as a trophic position indicator in grazers. Chloroplast C-16 and C-18 polyunsaturated FA were more affected by phosphate than C-20 and C-22 highly unsaturated FA (HUFA). The relative stability of stearidonic acid to phosphate in cryptophytes and haptophytes pinpointed this FA as a suited marker for both microalgae groups. Taken all species together, phosphate deprivation and taxonomy accounted for 20.8 and 50.7% of total FA variation, respectively. HUFA were minimally affected by phosphate indicating their suitability as indicators of phytoplankton trophic value. The asymptotic relationship between HUFA and phosphorus cell content suggested mineral composition (phosphorus) could be more important than HUFA content as attribute of marine microalgae nutritional value at the species level.
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Affiliation(s)
- José Pedro Cañavate
- IFAPA Centro El Toruño. Andalusia Research and Training Institute for Fisheries and Agriculture, 11500-El Puerto de Santa María, Cádiz, Spain.
| | - Isabel Armada
- IFAPA Centro El Toruño. Andalusia Research and Training Institute for Fisheries and Agriculture, 11500-El Puerto de Santa María, Cádiz, Spain
| | - Ismael Hachero-Cruzado
- IFAPA Centro El Toruño. Andalusia Research and Training Institute for Fisheries and Agriculture, 11500-El Puerto de Santa María, Cádiz, Spain
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Interactions between P-limitation and different C conditions on the fatty acid composition of an extremophile microalga. Extremophiles 2011; 15:597-609. [DOI: 10.1007/s00792-011-0390-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 07/04/2011] [Indexed: 11/25/2022]
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Castruita M, Casero D, Karpowicz SJ, Kropat J, Vieler A, Hsieh SI, Yan W, Cokus S, Loo JA, Benning C, Pellegrini M, Merchant SS. Systems biology approach in Chlamydomonas reveals connections between copper nutrition and multiple metabolic steps. THE PLANT CELL 2011; 23:1273-92. [PMID: 21498682 PMCID: PMC3101551 DOI: 10.1105/tpc.111.084400] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 03/02/2011] [Accepted: 03/27/2011] [Indexed: 05/18/2023]
Abstract
In this work, we query the Chlamydomonas reinhardtii copper regulon at a whole-genome level. Our RNA-Seq data simulation and analysis pipeline validated a 2-fold cutoff and 10 RPKM (reads per kilobase of mappable length per million mapped reads) (~1 mRNA per cell) to reveal 63 CRR1 targets plus another 86 copper-responsive genes. Proteomic and immunoblot analyses captured 25% of the corresponding proteins, whose abundance was also dependent on copper nutrition, validating transcriptional regulation as a major control mechanism for copper signaling in Chlamydomonas. The impact of copper deficiency on the expression of several O₂-dependent enzymes included steps in lipid modification pathways. Quantitative lipid profiles indicated increased polyunsaturation of fatty acids on thylakoid membrane digalactosyldiglycerides, indicating a global impact of copper deficiency on the photosynthetic apparatus. Discovery of a putative plastid copper chaperone and a membrane protease in the thylakoid suggest a mechanism for blocking copper utilization in the chloroplast. We also found an example of copper sparing in the N assimilation pathway: the replacement of copper amine oxidase by a flavin-dependent backup enzyme. Forty percent of the targets are previously uncharacterized proteins, indicating considerable potential for new discovery in the biology of copper.
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Affiliation(s)
- Madeli Castruita
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095
| | - David Casero
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California 90095
- Institute of Genomics and Proteomics, University of California, Los Angeles, California 90095
| | - Steven J. Karpowicz
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095
| | - Janette Kropat
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095
| | - Astrid Vieler
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Scott I. Hsieh
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095
| | - Weihong Yan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095
| | - Shawn Cokus
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California 90095
| | - Joseph A. Loo
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095
- Institute of Genomics and Proteomics, University of California, Los Angeles, California 90095
- Department of Biological Chemistry, University of California, Los Angeles, California 90095
| | - Christoph Benning
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Matteo Pellegrini
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California 90095
- Institute of Genomics and Proteomics, University of California, Los Angeles, California 90095
| | - Sabeeha S. Merchant
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095
- Institute of Genomics and Proteomics, University of California, Los Angeles, California 90095
- Address correspondence to
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Tocher DR, Leaver MJ, Hodgson PA. Recent advances in the biochemistry and molecular biology of fatty acyl desaturases. Prog Lipid Res 1998; 37:73-117. [PMID: 9829122 DOI: 10.1016/s0163-7827(98)00005-8] [Citation(s) in RCA: 227] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Affiliation(s)
- D R Tocher
- NERC Unit of Aquatic Biochemistry, School of Natural Sciences, University of Stirling, Scotland, U.K
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Sato N, Sonoike K, Kawaguchi A, Tsuzuki M. Contribution of lowered unsaturation levels of chloroplast lipids to high temperature tolerance of photosynthesis in Chlamydomonas reinhardtii. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 1996. [DOI: 10.1016/s1011-1344(96)07389-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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