1
|
Pérez-Pérez ME, Mallén-Ponce MJ, Odriozola-Gil Y, Rubio A, Salas JJ, Martínez-Force E, Pérez-Pulido AJ, Crespo JL. Lipid turnover through lipophagy in the newly identified extremophilic green microalga Chlamydomonas urium. THE NEW PHYTOLOGIST 2024; 243:284-298. [PMID: 38730535 DOI: 10.1111/nph.19811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 04/19/2024] [Indexed: 05/13/2024]
Abstract
Autophagy is a central degradative pathway highly conserved among eukaryotes, including microalgae, which remains unexplored in extremophilic organisms. In this study, we described and characterized autophagy in the newly identified extremophilic green microalga Chlamydomonas urium, which was isolated from an acidic environment. The nuclear genome of C. urium was sequenced, assembled and annotated in order to identify autophagy-related genes. Transmission electron microscopy, immunoblotting, metabolomic and photosynthetic analyses were performed to investigate autophagy in this extremophilic microalga. The analysis of the C. urium genome revealed the conservation of core autophagy-related genes. We investigated the role of autophagy in C. urium by blocking autophagic flux with the vacuolar ATPase inhibitor concanamycin A. Our results indicated that inhibition of autophagic flux in this microalga resulted in a pronounced accumulation of triacylglycerols and lipid droplets (LDs). Metabolomic and photosynthetic analyses indicated that C. urium cells with impaired vacuolar function maintained an active metabolism. Such effects were not observed in the neutrophilic microalga Chlamydomonas reinhardtii. Inhibition of autophagic flux in C. urium uncovered an active recycling of LDs through lipophagy, a selective autophagy pathway for lipid turnover. This study provided the metabolic basis by which extremophilic algae are able to catabolize lipids in the vacuole.
Collapse
Affiliation(s)
- María Esther Pérez-Pérez
- Instituto de Bioquímica Vegetal y Fotosíntesis (CSIC-Universidad de Sevilla), 41092, Sevilla, Spain
| | - Manuel J Mallén-Ponce
- Instituto de Bioquímica Vegetal y Fotosíntesis (CSIC-Universidad de Sevilla), 41092, Sevilla, Spain
| | - Yosu Odriozola-Gil
- Instituto de Bioquímica Vegetal y Fotosíntesis (CSIC-Universidad de Sevilla), 41092, Sevilla, Spain
| | - Alejandro Rubio
- Centro Andaluz de Biología del Desarrollo (CABD, UPO-CSIC-JA), Faculty of Experimental Sciences (Genetics Department), University Pablo de Olavide, 41013, Sevilla, Spain
| | - Joaquín J Salas
- Instituto de la Grasa (CSIC), Ctra Utrera Km1, Ed. 46, 41013, Sevilla, Spain
| | | | - Antonio J Pérez-Pulido
- Centro Andaluz de Biología del Desarrollo (CABD, UPO-CSIC-JA), Faculty of Experimental Sciences (Genetics Department), University Pablo de Olavide, 41013, Sevilla, Spain
| | - José L Crespo
- Instituto de Bioquímica Vegetal y Fotosíntesis (CSIC-Universidad de Sevilla), 41092, Sevilla, Spain
| |
Collapse
|
2
|
Chauhan M, Arshi SA, Narayanan N, Arfin HU, Sharma A. A mechanistic insight on how Compromised Hydrolysis of Triacylglycerol 7 (CHT7) restrains the involvement of it's CXC domain from quiescence repression. Int J Biol Macromol 2024; 265:130844. [PMID: 38484809 DOI: 10.1016/j.ijbiomac.2024.130844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 03/03/2024] [Accepted: 03/11/2024] [Indexed: 03/18/2024]
Abstract
CHT7 is a regulator of quiescence repression in Chlamydomonas reinhardtii. Initially, CHT7's repression activity was thought to be managed by its DNA-binding CXC domain. Later, it was found that the CHT7-CXC domain is dispensable for CHT7's activities. Rather, CHT7's predicted protein domains were proposed to be involved in regulation activities by binding to other repressors in the cell. Yet, it remains unclear why and how CHT7 refrains its CXC domain from participating in any transcriptional activities. The question becomes more intriguing, since CXC binding regions are available in promoter regions of some of the misregulated genes in CHT7 mutant (cht7). Through biophysical experiments and molecular dynamics approaches, we studied the DNA recognition behavior of CHT7-CXC. The results indicate that this domain possesses sequence selectivity due to the differential binding abilities of its subdomains. Further, to understand if the case is that CXC loses its DNA binding capabilities in the vicinity of other repressors, we examined CHT7-CXC's DNA binding stability under the spatial constraint conditions created through fusing CHT7-CXC with AsLOV2. The results show limited ability of CHT7-CXC to withstand steric forces and provide insights to why and how algal cells may hold back CHT7-CXC's indulgence in quiescence repression. CLASSIFICATIONS: Biological Sciences, Biophysics and Computational Biology.
Collapse
Affiliation(s)
- Manisha Chauhan
- Multidisciplinary Centre for Advanced Research and Studies, Jamia Millia Islamia, New Delhi 110025, India
| | - Syeda Amna Arshi
- Multidisciplinary Centre for Advanced Research and Studies, Jamia Millia Islamia, New Delhi 110025, India
| | - Naveen Narayanan
- Regional Centre for Biotechnology, NCR-Cluster Faridabad, Haryana 121001, India
| | - Haseeb Ul Arfin
- Multidisciplinary Centre for Advanced Research and Studies, Jamia Millia Islamia, New Delhi 110025, India
| | - Amit Sharma
- Multidisciplinary Centre for Advanced Research and Studies, Jamia Millia Islamia, New Delhi 110025, India.
| |
Collapse
|
3
|
Miklaszewska M, Zienkiewicz K, Klugier-Borowska E, Rygielski M, Feussner I, Zienkiewicz A. CALEOSIN 1 interaction with AUTOPHAGY-RELATED PROTEIN 8 facilitates lipid droplet microautophagy in seedlings. PLANT PHYSIOLOGY 2023; 193:2361-2380. [PMID: 37619984 PMCID: PMC10663143 DOI: 10.1093/plphys/kiad471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 06/16/2023] [Accepted: 08/05/2023] [Indexed: 08/26/2023]
Abstract
Lipid droplets (LDs) of seed tissues are storage organelles for triacylglycerols (TAGs) that provide the energy and carbon for seedling establishment. In the major route of LD degradation (lipolysis), TAGs are mobilized by lipases. However, LDs may also be degraded via lipophagy, a type of selective autophagy, which mediates LD delivery to vacuoles or lysosomes. The exact mechanisms of LD degradation and the mobilization of their content in plants remain unresolved. Here, we provide evidence that LDs are degraded via a process morphologically resembling microlipophagy in Arabidopsis (Arabidopsis thaliana) seedlings. We observed the entry and presence of LDs in the central vacuole as well as their breakdown. Moreover, we show co-localization of AUTOPHAGY-RELATED PROTEIN 8b (ATG8b) and LDs during seed germination and localization of lipidated ATG8 (ATG8-PE) to the LD fraction. We further demonstrate that structural LD proteins from the caleosin family, CALEOSIN 1 (CLO1), CALEOSIN 2 (CLO2), and CALEOSIN 3 (CLO3), interact with ATG8 proteins and possess putative ATG8-interacting motifs (AIMs). Deletion of the AIM localized directly before the proline knot disrupts the interaction of CLO1 with ATG8b, suggesting a possible role of this region in the interaction between these proteins. Collectively, we provide insights into LD degradation by microlipophagy in germinating seeds with a particular focus on the role of structural LD proteins in this process.
Collapse
Affiliation(s)
- Magdalena Miklaszewska
- Department of Plant Physiology and Biotechnology, University of Gdańsk, Wita Stwosza 59, Gdańsk 80-308, Poland
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Justus-von-Liebig-Weg 11, Goettingen 37077, Germany
| | - Krzysztof Zienkiewicz
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Justus-von-Liebig-Weg 11, Goettingen 37077, Germany
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4, 87-100 Toruń, Poland
| | - Ewa Klugier-Borowska
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4, 87-100 Toruń, Poland
| | - Marcin Rygielski
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4, 87-100 Toruń, Poland
| | - Ivo Feussner
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Justus-von-Liebig-Weg 11, Goettingen 37077, Germany
- Service Unit for Metabolomics and Lipidomics, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Justus-von-Liebig-Weg 11, Goettingen 37077, Germany
- Department of Plant Biochemistry, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Justus-von-Liebig-Weg 11, Goettingen 37077, Germany
| | - Agnieszka Zienkiewicz
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Justus-von-Liebig-Weg 11, Goettingen 37077, Germany
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4, 87-100 Toruń, Poland
| |
Collapse
|
4
|
McQuillan JL, Cutolo EA, Evans C, Pandhal J. Proteomic characterization of a lutein-hyperaccumulating Chlamydomonas reinhardtii mutant reveals photoprotection-related factors as targets for increasing cellular carotenoid content. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:166. [PMID: 37925447 PMCID: PMC10625216 DOI: 10.1186/s13068-023-02421-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 10/28/2023] [Indexed: 11/06/2023]
Abstract
BACKGROUND Microalgae are emerging hosts for the sustainable production of lutein, a high-value carotenoid; however, to be commercially competitive with existing systems, their capacity for lutein sequestration must be augmented. Previous attempts to boost microalgal lutein production have focussed on upregulating carotenoid biosynthetic enzymes, in part due to a lack of metabolic engineering targets for expanding lutein storage. RESULTS Here, we isolated a lutein hyper-producing mutant of the model green microalga Chlamydomonas reinhardtii and characterized the metabolic mechanisms driving its enhanced lutein accumulation using label-free quantitative proteomics. Norflurazon- and high light-resistant C. reinhardtii mutants were screened to yield four mutant lines that produced significantly more lutein per cell compared to the CC-125 parental strain. Mutant 5 (Mut-5) exhibited a 5.4-fold increase in lutein content per cell, which to our knowledge is the highest fold increase of lutein in C. reinhardtii resulting from mutagenesis or metabolic engineering so far. Comparative proteomics of Mut-5 against its parental strain CC-125 revealed an increased abundance of light-harvesting complex-like proteins involved in photoprotection, among differences in pigment biosynthesis, central carbon metabolism, and translation. Further characterization of Mut-5 under varying light conditions revealed constitutive overexpression of the photoprotective proteins light-harvesting complex stress-related 1 (LHCSR1) and LHCSR3 and PSII subunit S regardless of light intensity, and increased accrual of total chlorophyll and carotenoids as light intensity increased. Although the photosynthetic efficiency of Mut-5 was comparatively lower than CC-125, the amplitude of non-photochemical quenching responses of Mut-5 was 4.5-fold higher than in CC-125 at low irradiance. CONCLUSIONS We used C. reinhardtii as a model green alga and identified light-harvesting complex-like proteins (among others) as potential metabolic engineering targets to enhance lutein accumulation in microalgae. These have the added value of imparting resistance to high light, although partially compromising photosynthetic efficiency. Further genetic characterization and engineering of Mut-5 could lead to the discovery of unknown players in photoprotective mechanisms and the development of a potent microalgal lutein production system.
Collapse
Affiliation(s)
- Josie L McQuillan
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK.
| | - Edoardo Andrea Cutolo
- Laboratory of Photosynthesis and Bioenergy, Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Caroline Evans
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK
| | - Jagroop Pandhal
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK.
| |
Collapse
|
5
|
Murison V, Hérault J, Schoefs B, Marchand J, Ulmann L. Bioinformatics-Based Screening Approach for the Identification and Characterization of Lipolytic Enzymes from the Marine Diatom Phaeodactylum tricornutum. Mar Drugs 2023; 21:md21020125. [PMID: 36827166 PMCID: PMC9964374 DOI: 10.3390/md21020125] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/13/2023] [Accepted: 02/14/2023] [Indexed: 02/17/2023] Open
Abstract
Oleaginous diatoms accumulate lipids of biotechnological interest when exposed to nutrient stress conditions such as nitrogen starvation. While accumulation mechanisms are well-known and have been engineered to improve lipid production, degradation mechanisms remain poorly investigated in diatoms. Identifying lipid-degrading enzymes is the initial step to understanding the catabolic processes. In this study, an in silico screening of the genome of Phaeodactylum tricornutum led to the identification of 57 putative triacylglycerol lipases (EC 3.1.1.3) grouped in 4 families. Further analysis revealed the presence of conserved domains and catalytic residues of lipases. Physico-chemical characteristics and subcellular localization predictions highlighted that a majority of these putative proteins are hydrophilic and cytosolic, suggesting they could be recruited to lipid droplets directly from the cytosol. Among the 57 identified putative proteins, three lipases were identified as possibly involved in lipophagy due to a potential vacuolar localization. The expression of the mRNA corresponding to the 57 proteins was then searched in 3 transcriptomic datasets obtained under nitrogen starvation. Nine genes were highly regulated and were considered as encoding enzymes with a probable important function in lipid catabolism. A tertiary structure prediction of these nine candidates yielded eight functional 3D models. Among those, two downregulated enzymes, Phatr3_J54974 and Phatr3_EG00720, were highlighted as good targets for future functional genomics and purification studies to investigate their role in lipid degradation.
Collapse
Affiliation(s)
- Victor Murison
- BiOSSE, Biology of Organisms: Stress, Health, Environment, Département Génie Biologique, Institut Universitaire de Technologie, Le Mans Université, F-53020 Laval, France
| | - Josiane Hérault
- BiOSSE, Biology of Organisms: Stress, Health, Environment, Département Génie Biologique, Institut Universitaire de Technologie, Le Mans Université, F-53020 Laval, France
| | - Benoît Schoefs
- BiOSSE, Biology of Organisms: Stress, Health, Environment, UFR Sciences et Techniques, Le Mans Université, F-72085 Le Mans, France
| | - Justine Marchand
- BiOSSE, Biology of Organisms: Stress, Health, Environment, UFR Sciences et Techniques, Le Mans Université, F-72085 Le Mans, France
| | - Lionel Ulmann
- BiOSSE, Biology of Organisms: Stress, Health, Environment, Département Génie Biologique, Institut Universitaire de Technologie, Le Mans Université, F-53020 Laval, France
- Correspondence:
| |
Collapse
|
6
|
Xu W, Li J, Zhang L, Zhang X, Zhao H, Guo F, Wang Y, Wang P, Chen Y, Ni D, Wang M. Metabolome and RNA-seq Analysis of Responses to Nitrogen Deprivation and Resupply in Tea Plant ( Camellia sinensis) Roots. FRONTIERS IN PLANT SCIENCE 2022; 13:932720. [PMID: 36092416 PMCID: PMC9459018 DOI: 10.3389/fpls.2022.932720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 06/09/2022] [Indexed: 06/15/2023]
Abstract
Nitrogen (N) is an important contributor in regulating plant growth and development as well as secondary metabolites synthesis, so as to promote the formation of tea quality and flavor. Theanine, polyphenols, and caffeine are important secondary metabolites in tea plant. In this study, the responses of Camellia sinensis roots to N deprivation and resupply were investigated by metabolome and RNA-seq analysis. N deficiency induced content increase for most amino acids (AAs) and reduction for the remaining AAs, polyphenols, and caffeine. After N recovery, the decreased AAs and polyphenols showed a varying degree of recovery in content, but caffeine did not. Meanwhile, theanine increased in content, but its related synthetic genes were down-regulated, probably due to coordination of the whole N starvation regulatory network. Flavonoids-related pathways were relatively active following N stress according to KEGG enrichment analysis. Gene co-expression analysis revealed TCS2, AMT1;1, TAT2, TS, and GOGAT as key genes, and TFs like MYB, bHLH, and NAC were also actively involved in N stress responses in C. sinensis roots. These findings facilitate the understanding of the molecular mechanism of N regulation in tea roots and provide genetic reference for improving N use efficiency in tea plant.
Collapse
Affiliation(s)
- Wenluan Xu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Urban Agriculture in Central China (Ministry of Agriculture), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Jing Li
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Urban Agriculture in Central China (Ministry of Agriculture), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Luyu Zhang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Urban Agriculture in Central China (Ministry of Agriculture), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Xuyang Zhang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Urban Agriculture in Central China (Ministry of Agriculture), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Hua Zhao
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Urban Agriculture in Central China (Ministry of Agriculture), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Fei Guo
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Urban Agriculture in Central China (Ministry of Agriculture), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Yu Wang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Urban Agriculture in Central China (Ministry of Agriculture), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Pu Wang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Urban Agriculture in Central China (Ministry of Agriculture), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Yuqiong Chen
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Urban Agriculture in Central China (Ministry of Agriculture), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Dejiang Ni
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Urban Agriculture in Central China (Ministry of Agriculture), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Mingle Wang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Urban Agriculture in Central China (Ministry of Agriculture), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| |
Collapse
|
7
|
Choi BY, Shim D, Kong F, Auroy P, Lee Y, Li-Beisson Y, Lee Y, Yamaoka Y. The Chlamydomonas transcription factor MYB1 mediates lipid accumulation under nitrogen depletion. THE NEW PHYTOLOGIST 2022; 235:595-610. [PMID: 35383411 DOI: 10.1111/nph.18141] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 03/29/2022] [Indexed: 06/14/2023]
Abstract
Microalgae accumulate high levels of oil under stress, but the underlying biosynthetic pathways are not fully understood. We sought to identify key regulators of lipid metabolism under stress conditions. We found that the Chlamydomonas reinhardtii gene encoding the MYB-type transcription factor MYB1 is highly induced under stress conditions. Two myb1 mutants accumulated less total fatty acids and storage lipids than their parental strain upon nitrogen (N) depletion. Transcriptome analysis revealed that genes involved in lipid metabolism are highly enriched in the wild-type but not in the myb1-1 mutant after 4 h of N depletion. Among these genes were several involved in the transport of fatty acids from the chloroplast to the endoplasmic reticulum (ER): acyl-ACP thioesterase (FAT1), Fatty Acid EXporters (FAX1, FAX2), and long-chain acyl-CoA synthetase1 (LACS1). Furthermore, overexpression of FAT1 in the chloroplast increased lipid production. These results suggest that, upon N depletion, MYB1 promotes lipid accumulation by facilitating fatty acid transport from the chloroplast to the ER. This study identifies MYB1 as an important positive regulator of lipid accumulation in C. reinhardtii upon N depletion, adding another player to the established regulators of this process, including NITROGEN RESPONSE REGULATOR 1 (NRR1) and TRIACYLGLYCEROL ACCUMULATION REGULATOR 1 (TAR1).
Collapse
Affiliation(s)
- Bae Young Choi
- Department of Life Science, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea
| | - Donghwan Shim
- Department of Biological Sciences, Chungnam National University, Daejeon, 34134, Korea
| | - Fantao Kong
- Department of Life Science, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea
- School of Bioengineering, Dalian University of Technology, Dalian, 116024, China
| | - Pascaline Auroy
- CEA, CNRS, BIAM, Institut de Biosciences et Biotechnologies Aix-Marseille, Aix Marseille Université, CEA Cadarache, Saint Paul-Lez-Durance, 13108, France
| | - Yuree Lee
- School of Biological Sciences, Seoul National University, Seoul, 08826, Korea
- Research Center for Plant Plasticity, Seoul National University, Seoul, 08826, Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, 08826, Korea
| | - Yonghua Li-Beisson
- CEA, CNRS, BIAM, Institut de Biosciences et Biotechnologies Aix-Marseille, Aix Marseille Université, CEA Cadarache, Saint Paul-Lez-Durance, 13108, France
| | - Youngsook Lee
- Department of Life Science, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea
| | - Yasuyo Yamaoka
- Division of Biotechnology, The Catholic University of Korea, Bucheon, 420-743, Korea
| |
Collapse
|
8
|
Saggere RMS, Lee CWJ, Chan ICW, Durnford DG, Nedelcu AM. A life-history trade-off gene with antagonistic pleiotropic effects on reproduction and survival in limiting environments. Proc Biol Sci 2022; 289:20212669. [PMID: 35078364 PMCID: PMC8790358 DOI: 10.1098/rspb.2021.2669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Although life-history trade-offs are central to life-history evolution, their mechanistic basis is often unclear. Traditionally, trade-offs are understood in terms of competition for limited resources among traits within an organism, which could be mediated by signal transduction pathways at the level of cellular metabolism. Nevertheless, trade-offs are also thought to be produced as a consequence of the performance of one activity generating negative consequences for other traits, or the result of genes or pathways that simultaneously regulate two life-history traits in opposite directions (antagonistic pleiotropy), independent of resource allocation. Yet examples of genes with antagonistic effects on life-history traits are limited. This study provides direct evidence for a gene-RLS1, that is involved in increasing survival in nutrient-limiting environments at a cost to immediate reproduction in the single-celled photosynthetic alga, Chlamydomonas reinhardtii. Specifically, we show that RLS1 mutants are unable to properly suppress their reproduction in phosphate-deprived conditions. Although these mutants have an immediate reproductive advantage relative to the parental strain, their long-term survival is negatively affected. Our data suggest that RLS1 is a bona fide life-history trade-off gene that suppresses immediate reproduction and ensures survival by downregulating photosynthesis in limiting environments, as part of the general acclimation response to nutrient deprivation in photosynthetic organisms.
Collapse
Affiliation(s)
- Rani M. S. Saggere
- Biology Department, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, Canada E3B 5A3
| | - Christopher W. J. Lee
- Biology Department, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, Canada E3B 5A3
| | - Irina C. W. Chan
- Biology Department, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, Canada E3B 5A3
| | - Dion G. Durnford
- Biology Department, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, Canada E3B 5A3
| | - Aurora M. Nedelcu
- Biology Department, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, Canada E3B 5A3
| |
Collapse
|
9
|
Scarsini M, Thiriet-Rupert S, Veidl B, Mondeguer F, Hu H, Marchand J, Schoefs B. The Transition Toward Nitrogen Deprivation in Diatoms Requires Chloroplast Stand-By and Deep Metabolic Reshuffling. FRONTIERS IN PLANT SCIENCE 2022; 12:760516. [PMID: 35126407 PMCID: PMC8811913 DOI: 10.3389/fpls.2021.760516] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 11/19/2021] [Indexed: 06/14/2023]
Abstract
Microalgae have adapted to face abiotic stresses by accumulating energy storage molecules such as lipids, which are also of interest to industries. Unfortunately, the impairment in cell division during the accumulation of these molecules constitutes a major bottleneck for the development of efficient microalgae-based biotechnology processes. To address the bottleneck, a multidisciplinary approach was used to study the mechanisms involved in the transition from nitrogen repletion to nitrogen starvation conditions in the marine diatom Phaeodactylum tricornutum that was cultured in a turbidostat. Combining data demonstrate that the different steps of nitrogen deficiency clustered together in a single state in which cells are in equilibrium with their environment. The switch between the nitrogen-replete and the nitrogen-deficient equilibrium is driven by intracellular nitrogen availability. The switch induces a major gene expression change, which is reflected in the reorientation of the carbon metabolism toward an energy storage mode while still operating as a metabolic flywheel. Although the photosynthetic activity is reduced, the chloroplast is kept in a stand-by mode allowing a fast resuming upon nitrogen repletion. Altogether, these results contribute to the understanding of the intricate response of diatoms under stress.
Collapse
Affiliation(s)
- Matteo Scarsini
- Metabolism, Bio-Engineering of Microalgal Molecules and Applications (MIMMA), Mer Molécules Santé, IUML—FR 3473 CNRS, Le Mans University, Le Mans, France
| | - Stanislas Thiriet-Rupert
- Metabolism, Bio-Engineering of Microalgal Molecules and Applications (MIMMA), Mer Molécules Santé, IUML—FR 3473 CNRS, Le Mans University, Le Mans, France
- Institut Pasteur, Genetics of Biofilms Laboratory, Paris, France
| | - Brigitte Veidl
- Metabolism, Bio-Engineering of Microalgal Molecules and Applications (MIMMA), Mer Molécules Santé, IUML—FR 3473 CNRS, Le Mans University, Le Mans, France
| | - Florence Mondeguer
- Phycotoxins Laboratory, Institut Français de Recherche pour l'Exploitation de la Mer, Nantes, France
| | - Hanhua Hu
- Key Laboratory of Algal Biology, Chinese Academy of Sciences, Wuhan, China
| | - Justine Marchand
- Metabolism, Bio-Engineering of Microalgal Molecules and Applications (MIMMA), Mer Molécules Santé, IUML—FR 3473 CNRS, Le Mans University, Le Mans, France
| | - Benoît Schoefs
- Metabolism, Bio-Engineering of Microalgal Molecules and Applications (MIMMA), Mer Molécules Santé, IUML—FR 3473 CNRS, Le Mans University, Le Mans, France
| |
Collapse
|
10
|
Li-Beisson Y, Kong F, Wang P, Lee Y, Kang BH. The disassembly of lipid droplets in Chlamydomonas. THE NEW PHYTOLOGIST 2021; 231:1359-1364. [PMID: 34028037 DOI: 10.1111/nph.17505] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 05/07/2021] [Indexed: 06/12/2023]
Abstract
Lipid droplets (LDs) are ubiquitous and specialized organelles in eukaryotic cells. Consisting of a triacylglycerol core surrounded by a monolayer of membrane lipids, LDs are decorated with proteins and have myriad functions, from carbon/energy storage to membrane lipid remodeling and signal transduction. The biogenesis and turnover of LDs are therefore tightly coordinated with cellular metabolic needs in a fluctuating environment. Lipid droplet turnover requires remodeling of the protein coat, lipolysis, autophagy and fatty acid β-oxidation. Several key components of these processes have been identified in Chlamydomonas (Chlamydomonas reinhardtii), including the major lipid droplet protein, a CXC-domain containing regulatory protein, the phosphatidylethanolamine-binding DTH1 (DELAYED IN TAG HYDROLYSIS1), two lipases and two enzymes involved in fatty acid β-oxidation. Here, we review LD turnover and discuss its physiological significance in Chlamydomonas, a major model green microalga in research on algal oil.
Collapse
Affiliation(s)
- Yonghua Li-Beisson
- CEA, CNRS, BIAM, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Aix-Marseille Univ, Saint Paul-Lez-Durance, 13108, France
| | - Fantao Kong
- School of Bioengineering, Dalian University of Technology, Dalian, 116024, China
| | - Pengfei Wang
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, 999077, China
| | - Youngsook Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Byung-Ho Kang
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, 999077, China
| |
Collapse
|
11
|
Young DY, Shachar-Hill Y. Large fluxes of fatty acids from membranes to triacylglycerol and back during N-deprivation and recovery in Chlamydomonas. PLANT PHYSIOLOGY 2021; 185:796-814. [PMID: 33822218 PMCID: PMC8133548 DOI: 10.1093/plphys/kiaa071] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/23/2020] [Indexed: 06/12/2023]
Abstract
Microalgae accumulate triacylglycerol (TAG) during nutrient deprivation and break it down after nutrient resupply, and these processes involve dramatic shifts in cellular carbon allocation. Due to the importance of algae in the global carbon cycle, and the potential of algal lipids as feedstock for chemical and fuel production, these processes are of both ecophysiological and biotechnological importance. However, the metabolism of TAG is not well understood, particularly the contributions of fatty acids (FAs) from different membrane lipids to TAG accumulation and the fate of TAG FAs during degradation. Here, we used isotopic labeling time course experiments on Chlamydomonas reinhardtii to track FA synthesis and transfer between lipid pools during nitrogen (N)-deprivation and resupply. When cells were labeled before N-deprivation, total levels of label in cellular FAs were unchanged during subsequent N-deprivation and later resupply, despite large fluxes into and out of TAG and membrane lipid pools. Detailed analyses of FA levels and labeling revealed that about one-third of acyl chains accumulating in TAG during N-deprivation derive from preexisting membrane lipids, and in total, at least 45% of TAG FAs passed through membrane lipids at one point. Notably, most acyl chains in membrane lipids during recovery after N-resupply come from TAG. Fluxes of polyunsaturated FAs from plastidic membranes into TAG during N-deprivation were particularly noteworthy. These findings demonstrate a high degree of integration of TAG and membrane lipid metabolism and highlight a role for TAG in storage and supply of membrane lipid components.
Collapse
Affiliation(s)
- Danielle Yvonne Young
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Yair Shachar-Hill
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, 48824, USA
| |
Collapse
|
12
|
Takeuchi T, Lin YT, Fekaris N, Umen J, Sears BB, Benning C. Modulation of CHT7 Complexes during Light/Dark- and Nitrogen-Mediated Life Cycle Transitions of Chlamydomonas. PLANT PHYSIOLOGY 2020; 184:1762-1774. [PMID: 33004613 PMCID: PMC7723089 DOI: 10.1104/pp.20.00864] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/21/2020] [Indexed: 06/11/2023]
Abstract
The Chlamydomonas reinhardtii Compromised Hydrolysis of Triacylglycerols7 (CHT7) protein has been previously implicated in the regulation of DNA metabolism and cell-cycle-related gene expression during nitrogen (N) deprivation, and its predicted protein interaction domains are necessary for function. Here, we examined impacts of the cht7 mutation during the cell division cycle under nutrient deficiency in light-dark synchronized cultures. We explored the potential mechanisms affecting CHT7 complex activities during the cell cycle and N starvation, with a focus on the possible interaction between CHT7 and the C. reinhardtii retinoblastoma tumor suppressor (RB) protein homolog MAT3. Notably, the absence of CHT7 did not negatively impact the synchrony of cell division and cell cycle progression during diel growth. Although the majority of CHT7 and MAT3/RB proteins were observed in separate complexes by blue native-PAGE, the two proteins coimmunoprecipitated both during synchronized growth and following N deprivation, suggesting the presence of low abundance subcomplexes containing CHT7 and MAT3/RB. Furthermore, we observed several phosphorylated isoforms of CHT7 under these conditions. To test the potential role of phosphorylation on the structure and function of CHT7, we performed site-directed mutagenesis of previously identified phosphorylated amino acids within CHT7. These phosphorylated residues were dispensable for CHT7 function, but phosphorylated variants of CHT7 persisted, indicating that yet-unidentified residues within CHT7 are also likely phosphorylated. Based on the interaction of CHT7 and MAT3/RB, we postulate the presence of a low-abundance or transient regulatory complex in C. reinhardtii that may be similar to DREAM-like complexes in other organisms.
Collapse
Affiliation(s)
- Tomomi Takeuchi
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Yang-Tsung Lin
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Nicholas Fekaris
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - James Umen
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Barbara B Sears
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Christoph Benning
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| |
Collapse
|
13
|
Takeuchi T, Sears BB, Lindeboom C, Lin YT, Fekaris N, Zienkiewicz K, Zienkiewicz A, Poliner E, Benning C. Chlamydomonas CHT7 Is Required for an Effective Quiescent State by Regulating Nutrient-Responsive Cell Cycle Gene Expression. THE PLANT CELL 2020; 32:1240-1269. [PMID: 32001503 PMCID: PMC7145468 DOI: 10.1105/tpc.19.00628] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 01/07/2020] [Accepted: 01/27/2020] [Indexed: 06/10/2023]
Abstract
COMPROMISED HYDROLYSIS OF TRIACYLGLYCEROLS7 (CHT7) in Chlamydomonas (Chlamydomonas reinhardtii) was previously shown to affect the transcription of a subset of genes during nitrogen (N)-replete growth and following N refeeding. Here, we show that an extensive derepression of genes involved in DNA metabolism and cell cycle-related processes, as well as downregulation of genes encoding oxidoreductases and nutrient transporters, occurs in the cht7 mutant during N deprivation. Cellular mutant phenotypes are consistent with the observed transcriptome misregulation, as cht7 cells fail to properly arrest growth, nuclear replication, and cell division following N deprivation. Reduction in cht7 colony formation following N refeeding is explained by its compromised viability during N deprivation and by the occurrence of abortive divisions during N refeeding. Surprisingly, the largely unstructured C-terminal half of CHT7 with predicted protein binding domains, but not the canonical CXC DNA binding domain, is essential for the ability of CHT7 to form stable complexes and reverse the cellular phenotypes and transcription levels in the cht7 mutant. Hence, although lacking the presumed DNA binding domain, CHT7 modulates the expression of cell cycle genes in response to N availability, which is essential for establishing an effective quiescent state and the coordinated resumption of growth following N refeeding.
Collapse
Affiliation(s)
- Tomomi Takeuchi
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Barbara B Sears
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Chase Lindeboom
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Yang-Tsung Lin
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Nicholas Fekaris
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Krzysztof Zienkiewicz
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Centre of Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland
| | - Agnieszka Zienkiewicz
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Centre of Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan 48824
| | - Eric Poliner
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Christoph Benning
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan 48824
| |
Collapse
|
14
|
Zienkiewicz A, Zienkiewicz K, Poliner E, Pulman JA, Du ZY, Stefano G, Tsai CH, Horn P, Feussner I, Farre EM, Childs KL, Brandizzi F, Benning C. The Microalga Nannochloropsis during Transition from Quiescence to Autotrophy in Response to Nitrogen Availability. PLANT PHYSIOLOGY 2020; 182:819-839. [PMID: 31740503 PMCID: PMC6997683 DOI: 10.1104/pp.19.00854] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 11/04/2019] [Indexed: 05/03/2023]
Abstract
The marine microalgae Nannochloropsis oceanica (CCMP1779) is a prolific producer of oil and is considered a viable and sustainable resource for biofuel feedstocks. Nitrogen (N) availability has a strong impact on the physiological status and metabolism of microalgal cells, but the exact nature of this response is poorly understood. To fill this gap we performed transcriptomic profiling combined with cellular and molecular analyses of N. oceanica CCMP1779 during the transition from quiescence to autotrophy. N deprivation-induced quiescence was accompanied by a strong reorganization of the photosynthetic apparatus and changes in the lipid homeostasis, leading to accumulation of triacylglycerol. Cell cycle activation and re-establishment of photosynthetic activity observed in response to resupply of the growth medium with N were accompanied by a rapid degradation of triacylglycerol stored in lipid droplets (LDs). Besides observing LD translocation into vacuoles, we also provide evidence for direct interaction between the LD surface protein (NoLDSP) and AUTOPHAGY-RELATED8 (NoATG8) protein and show a role of microlipophagy in LD turnover in N. oceanica CCMP1779. This knowledge is crucial not only for understanding the fundamental mechanisms controlling the cellular energy homeostasis in microalgal cells but also for development of efficient strategies to achieve higher algal biomass and better microalgal lipid productivity.
Collapse
Affiliation(s)
- Agnieszka Zienkiewicz
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Great Lakes Bioenergy Center, Michigan State University, East Lansing, Michigan 48824
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, 87-100 Toruń, Poland
| | - Krzysztof Zienkiewicz
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, 87-100 Toruń, Poland
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37073 Goettingen, Germany
| | - Eric Poliner
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Cell and Molecular Biology Program, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Jane A Pulman
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
- Center for Genomics-Enabled Plant Science, Michigan State University, East Lansing, Michigan 48824
| | - Zhi-Yan Du
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Giovanni Stefano
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Chia-Hong Tsai
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Patrick Horn
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Ivo Feussner
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37073 Goettingen, Germany
- Department of Plant Biochemistry, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, 37073 Goettingen, Germany
- Department of Plant Biochemistry, International Center for Advanced Studies of Energy Conversion (ICASEC), University of Goettingen, 37073 Goettingen, Germany
| | - Eva M Farre
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Kevin L Childs
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
- Center for Genomics-Enabled Plant Science, Michigan State University, East Lansing, Michigan 48824
| | - Federica Brandizzi
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Christoph Benning
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Great Lakes Bioenergy Center, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| |
Collapse
|
15
|
Zienkiewicz K, Zienkiewicz A. Degradation of Lipid Droplets in Plants and Algae-Right Time, Many Paths, One Goal. FRONTIERS IN PLANT SCIENCE 2020; 11:579019. [PMID: 33014002 PMCID: PMC7509404 DOI: 10.3389/fpls.2020.579019] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/24/2020] [Indexed: 05/05/2023]
Abstract
In eukaryotic cells, lipids in the form of triacylglycerols (TAGs) are the major reservoir of cellular carbon and energy. These TAGs are packed into specialized organelles called lipid droplets (LDs). They can be found in most, if not all, types of cells, from bacteria to human. Recent data suggest that rather than being simple storage organelles, LDs are very dynamic structures at the center of cellular metabolism. This is also true in plants and algae, where LDs have been implicated in many processes including energy supply; membrane structure, function, trafficking; and signal transduction. Plant and algal LDs also play a vital role in human life, providing multiple sources of food and fuel. Thus, a lot of attention has been paid to metabolism and function of these organelles in recent years. This review summarizes the most recent advances on LDs degradation as a key process for TAGs release. While the initial knowledge on this process came from studies in oilseeds, the findings of the last decade revealed high complexity and specific mechanisms of LDs degradation in plants and algae. This includes identification of numerous novel proteins associated with LDs as well as a prominent role for autophagy in this process. This review outlines, systemizes, and discusses the most current data on LDs catabolism in plants and algae.
Collapse
|
16
|
Kokabi K, Gorelova O, Zorin B, Didi-Cohen S, Itkin M, Malitsky S, Solovchenko A, Boussiba S, Khozin-Goldberg I. Lipidome Remodeling and Autophagic Respose in the Arachidonic-Acid-Rich Microalga Lobosphaera incisa Under Nitrogen and Phosphorous Deprivation. FRONTIERS IN PLANT SCIENCE 2020; 11:614846. [PMID: 33329680 PMCID: PMC7728692 DOI: 10.3389/fpls.2020.614846] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/02/2020] [Indexed: 05/09/2023]
Abstract
The green microalga Lobosphaera incisa accumulates triacylglycerols (TAGs) with exceptionally high levels of long-chain polyunsaturated fatty acid (LC-PUFA) arachidonic acid (ARA) under nitrogen (N) deprivation. Phosphorous (P) deprivation induces milder changes in fatty acid composition, cell ultrastructure, and growth performance. We hypothesized that the resource-demanding biosynthesis and sequestration of ARA-rich TAG in lipid droplets (LDs) are associated with the enhancement of catabolic processes, including membrane lipid turnover and autophagic activity. Although this work focuses mainly on N deprivation, a comparative analysis of N and P deprivation responses is included. The results of lipidomic profiling showed a differential impact of N and P deprivation on the reorganization of glycerolipids. The formation of TAG under N deprivation was associated with the enhanced breakdown of chloroplast glycerolipids and the formation of lyso-lipids. N-deprived cells displayed a profound reorganization of cell ultrastructure, including internalization of cellular material into autophagic vacuoles, concomitant with the formation of LDs, while P-deprived cells showed better cellular ultrastructural integrity. The expression of the hallmark autophagy protein ATG8 and the major lipid droplet protein (MLDP) genes were coordinately upregulated, but to different extents under either N or P deprivation. The expression of the Δ5-desaturase gene, involved in the final step of ARA biosynthesis, was coordinated with ATG8 and MLDP, exclusively under N deprivation. Concanamycin A, the inhibitor of vacuolar proteolysis and autophagic flux, suppressed growth and enhanced levels of ATG8 and TAG in N-replete cells. The proportions of ARA in TAG decreased with a concomitant increase in oleic acid under both N-replete and N-deprived conditions. The photosynthetic apparatus's recovery from N deprivation was impaired in the presence of the inhibitor, along with the delayed LD degradation. The GFP-ATG8 processing assay showed the release of free GFP in N-replete and N-deprived cells, supporting the existence of autophagic flux. This study provides the first insight into the homeostatic role of autophagy in L. incisa and points to a possible metabolic link between autophagy and ARA-rich TAG biosynthesis.
Collapse
Affiliation(s)
- Kamilya Kokabi
- The Albert Katz International School for Desert Studies, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of Drylands, The J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Olga Gorelova
- Department of Bioengineering, Faculty of Biology, Moscow State University, GSP-1, Moscow, Russia
| | - Boris Zorin
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of 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 of Drylands, The J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Maxim Itkin
- Metabolic Profiling Unit, Life Science Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Sergey Malitsky
- Metabolic Profiling Unit, Life Science Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Alexei Solovchenko
- Department of Bioengineering, Faculty of Biology, Moscow State University, GSP-1, Moscow, Russia
- Institute of Natural Sciences, Derzhavin Tambov State University, Tambov, Russia
- Peoples Friendship University of Russia (RUDN University), Moscow, Russia
| | - Sammy Boussiba
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of Drylands, The J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Inna Khozin-Goldberg
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of Drylands, The J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Midreshet Ben-Gurion, Israel
| |
Collapse
|
17
|
Kokabi K, Gorelova O, Ismagulova T, Itkin M, Malitsky S, Boussiba S, Solovchenko A, Khozin-Goldberg I. Metabolomic foundation for differential responses of lipid metabolism to nitrogen and phosphorus deprivation in an arachidonic acid-producing green microalga. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 283:95-115. [PMID: 31128719 DOI: 10.1016/j.plantsci.2019.02.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 01/05/2019] [Accepted: 02/11/2019] [Indexed: 05/08/2023]
Abstract
The green oleaginous microalga Lobosphaera incisa accumulates storage lipids triacylglycerols (TAG) enriched in the long-chain polyunsaturated fatty acid arachidonic acid under nitrogen (N) deprivation. In contrast, under phosphorous (P) deprivation, the production of the monounsaturated oleic acid prevails. We compared physiological responses, ultrastructural, and metabolic consequences of L. incisa acclimation to N and P deficiency to provide novel insights into the key determinants of ARA accumulation. Differential responses to nutrient deprivation on growth performance, carbon-to-nitrogen stoichiometry, membrane lipid composition and TAG accumulation were demonstrated. Ultrastructural analyses suggested a dynamic role for vacuoles in sustaining cell homeostasis under conditions of different nutrient availability and their involvement in autophagy in L. incisa. Paralleling ARA-rich TAG accumulation in lipid droplets, N deprivation triggered intensive chloroplast dismantling and promoted catabolic processes. Metabolome analysis revealed depletion of amino acids and pyrimidines, and repression of numerous biosynthetic hubs to favour TAG biosynthesis under N deprivation. Under P deprivation, despite the relatively low growth penalties, the presence of the endogenous P reserves and the characteristic lipid remodelling, metabolic signatures of energy deficiency were revealed. Metabolome adjustments to P deprivation included depletion in ATP and phosphorylated nucleotides, increased levels of TCA-cycle intermediates and osmoprotectants. We conclude that characteristic cellular and metabolome adjustments tailor the adaptive responses of L. incisa to N and P deprivation modulating its LC-PUFA production.
Collapse
Affiliation(s)
- Kamilya Kokabi
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of Drylands, The J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, 8499000, Israel
| | - Olga Gorelova
- Department of Bioengineering, Faculty of Biology, Moscow State University, GSP-1, Moscow, 119234, Russia
| | - Tatiana Ismagulova
- Department of Bioengineering, Faculty of Biology, Moscow State University, GSP-1, Moscow, 119234, Russia
| | - Maxim Itkin
- Metabolic Profiling Unit, Life Science Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Sergey Malitsky
- Metabolic Profiling Unit, Life Science Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Sammy Boussiba
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of Drylands, The J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, 8499000, Israel
| | - Alexei Solovchenko
- Department of Bioengineering, Faculty of Biology, Moscow State University, GSP-1, Moscow, 119234, Russia; Peoples Friendship University of Russia (RUDN University), Moscow, 117198, Russia
| | - Inna Khozin-Goldberg
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of Drylands, The J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, 8499000, Israel.
| |
Collapse
|
18
|
Warakanont J, Li-Beisson Y, Benning C. LIP4 Is Involved in Triacylglycerol Degradation in Chlamydomonas reinhardtii. PLANT & CELL PHYSIOLOGY 2019; 60:1250-1259. [PMID: 30796452 DOI: 10.1093/pcp/pcz037] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 02/13/2019] [Indexed: 05/03/2023]
Abstract
Degradation of the storage compound triacylglycerol (TAG) is a crucial process in response to environmental stimuli. In microalgae, this process is important for re-growth when conditions become favorable after cells have experienced stresses. Mobilization of TAG is initiated by actions of lipases causing the release of glycerol and free fatty acids, which can be further broken down for energy production or recycled to synthesize membrane lipids. Although key enzymes in the process, TAG lipases remain to be characterized in the model green alga Chlamydomonas reinhardtii. Here, we describe the functional analysis of a putative TAG lipase, i.e. LIP4, which shares 44% amino acid identity with the major TAG lipase in Arabidopsis (SUGAR DEPENDENT1-SDP1). The LIP4 transcript level was downregulated during nitrogen deprivation when TAG accumulates, but was upregulated during nitrogen resupply (NR) when TAG was degraded. Both artificial microRNA and insertional mutants showed a delay in TAG mobilization during NR. The difference in TAG degradation was more pronounced when the cultures were incubated without acetate in the dark. Furthermore, the lip4 insertional mutants over-accumulated TAG during optimal growth conditions. Taken together, the results suggest to us that LIP4 likely acts as a TAG lipase and plays a role in TAG homeostasis in Chlamydomonas.
Collapse
Affiliation(s)
- Jaruswan Warakanont
- Department of Botany, Faculty of Science, Kasetsart University, 50 Ngamwongwan Road, Lad Yao, Chatuchak, Bangkok, Thailand
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
- Aix Marseille University, CEA, CNRS, BIAM, Saint-Paul-Lez-Durance, Marseille F, France
| | - Yonghua Li-Beisson
- Aix Marseille University, CEA, CNRS, BIAM, Saint-Paul-Lez-Durance, Marseille F, France
| | - Christoph Benning
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
- Plant Research Laboratory, US Department of Energy, Michigan State University, East Lansing, MI, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| |
Collapse
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
Liang Y, Kong F, Torres-Romero I, Burlacot A, Cuine S, Légeret B, Billon E, Brotman Y, Alseekh S, Fernie AR, Beisson F, Peltier G, Li-Beisson Y. Branched-Chain Amino Acid Catabolism Impacts Triacylglycerol Homeostasis in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2019; 179:1502-1514. [PMID: 30728273 PMCID: PMC6446750 DOI: 10.1104/pp.18.01584] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 01/30/2019] [Indexed: 05/05/2023]
Abstract
Nitrogen (N) starvation-induced triacylglycerol (TAG) synthesis, and its complex relationship with starch metabolism in algal cells, has been intensively studied; however, few studies have examined the interaction between amino acid metabolism and TAG biosynthesis. Here, via a forward genetic screen for TAG homeostasis, we isolated a Chlamydomonas (Chlamydomonas reinhardtii) mutant (bkdE1α) that is deficient in the E1α subunit of the branched-chain ketoacid dehydrogenase (BCKDH) complex. Metabolomics analysis revealed a defect in the catabolism of branched-chain amino acids in bkdE1α Furthermore, this mutant accumulated 30% less TAG than the parental strain during N starvation and was compromised in TAG remobilization upon N resupply. Intriguingly, the rate of mitochondrial respiration was 20% to 35% lower in bkdE1α compared with the parental strains. Three additional knockout mutants of the other components of the BCKDH complex exhibited phenotypes similar to that of bkdE1α Transcriptional responses of BCKDH to different N status were consistent with its role in TAG homeostasis. Collectively, these results indicate that branched-chain amino acid catabolism contributes to TAG metabolism by providing carbon precursors and ATP, thus highlighting the complex interplay between distinct subcellular metabolisms for oil storage in green microalgae.
Collapse
Affiliation(s)
- Yuanxue Liang
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Fantao Kong
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Ismael Torres-Romero
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Adrien Burlacot
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Stéphan Cuine
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Bertrand Légeret
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Emmanuelle Billon
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Yariv Brotman
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Saleh Alseekh
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Alisdair R Fernie
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Fred Beisson
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Gilles Peltier
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Yonghua Li-Beisson
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| |
Collapse
|
21
|
Takeuchi T, Benning C. Nitrogen-dependent coordination of cell cycle, quiescence and TAG accumulation in Chlamydomonas. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:292. [PMID: 31890020 PMCID: PMC6927116 DOI: 10.1186/s13068-019-1635-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 12/12/2019] [Indexed: 05/07/2023]
Abstract
Microalgae hold great promises as sustainable cellular factories for the production of alternative fuels, feeds, and biopharmaceuticals for human health. While the biorefinery approach for fuels along with the coproduction of high-value compounds with industrial, therapeutic, or nutraceutical applications have the potential to make algal biofuels more economically viable, a number of challenges continue to hamper algal production systems at all levels. One such hurdle includes the metabolic trade-off often observed between the increased yields of desired products, such as triacylglycerols (TAG), and the growth of an organism. Initial genetic engineering strategies to improve lipid productivity in microalgae, which focused on overproducing the enzymes involved in fatty acid and TAG biosynthesis or inactivating competing carbon (C) metabolism, have seen some successes albeit at the cost of often greatly reduced biomass. Emergent approaches that aim at modifying the dynamics of entire metabolic pathways by engineering of pertinent transcription factors or signaling networks appear to have successfully achieved a balance between growth and neutral lipid accumulation. However, the biological knowledge of key signaling networks and molecular components linking these two processes is still incomplete in photosynthetic eukaryotes, making it difficult to optimize metabolic engineering strategies for microalgae. Here, we focus on nitrogen (N) starvation of the model green microalga, Chlamydomonas reinhardtii, to present the current understanding of the nutrient-dependent switch between proliferation and quiescence, and the drastic reprogramming of metabolism that results in the storage of C compounds following N starvation. We discuss the potential components mediating the transcriptional repression of cell cycle genes and the establishment of quiescence in Chlamydomonas, and highlight the importance of signaling pathways such as those governed by the target of rapamycin (TOR) and sucrose nonfermenting-related (SnRK) kinases in the coordination of metabolic status with cellular growth. A better understanding of how the cell division cycle is regulated in response to nutrient scarcity and of the signaling pathways linking cellular growth to energy and lipid homeostasis, is essential to improve the prospects of biofuels and biomass production in microalgae.
Collapse
Affiliation(s)
- Tomomi Takeuchi
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824 USA
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824 USA
| | - Christoph Benning
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824 USA
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824 USA
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
| |
Collapse
|
22
|
Kong F, Burlacot A, Liang Y, Légeret B, Alseekh S, Brotman Y, Fernie AR, Krieger-Liszkay A, Beisson F, Peltier G, Li-Beisson Y. Interorganelle Communication: Peroxisomal MALATE DEHYDROGENASE2 Connects Lipid Catabolism to Photosynthesis through Redox Coupling in Chlamydomonas. THE PLANT CELL 2018; 30:1824-1847. [PMID: 29997239 PMCID: PMC6139685 DOI: 10.1105/tpc.18.00361] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 06/12/2018] [Accepted: 07/10/2018] [Indexed: 05/17/2023]
Abstract
Plants and algae must tightly coordinate photosynthetic electron transport and metabolic activities given that they often face fluctuating light and nutrient conditions. The exchange of metabolites and signaling molecules between organelles is thought to be central to this regulation but evidence for this is still fragmentary. Here, we show that knocking out the peroxisome-located MALATE DEHYDROGENASE2 (MDH2) of Chlamydomonas reinhardtii results in dramatic alterations not only in peroxisomal fatty acid breakdown but also in chloroplast starch metabolism and photosynthesis. mdh2 mutants accumulated 50% more storage lipid and 2-fold more starch than the wild type during nitrogen deprivation. In parallel, mdh2 showed increased photosystem II yield and photosynthetic CO2 fixation. Metabolite analyses revealed a >60% reduction in malate, together with increased levels of NADPH and H2O2 in mdh2 Similar phenotypes were found upon high light exposure. Furthermore, based on the lack of starch accumulation in a knockout mutant of the H2O2-producing peroxisomal ACYL-COA OXIDASE2 and on the effects of H2O2 supplementation, we propose that peroxisome-derived H2O2 acts as a regulator of chloroplast metabolism. We conclude that peroxisomal MDH2 helps photoautotrophs cope with nitrogen scarcity and high light by transmitting the redox state of the peroxisome to the chloroplast by means of malate shuttle- and H2O2-based redox signaling.
Collapse
Affiliation(s)
- Fantao Kong
- Aix Marseille University, CEA, CNRS, BIAM, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, F-13108 Saint Paul-Lez-Durance, France
| | - Adrien Burlacot
- Aix Marseille University, CEA, CNRS, BIAM, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, F-13108 Saint Paul-Lez-Durance, France
| | - Yuanxue Liang
- Aix Marseille University, CEA, CNRS, BIAM, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, F-13108 Saint Paul-Lez-Durance, France
| | - Bertrand Légeret
- Aix Marseille University, CEA, CNRS, BIAM, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, F-13108 Saint Paul-Lez-Durance, France
| | - Saleh Alseekh
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
- Center of Plant System Biology and Biotechnology, 4000 Plovdiv, Bulgaria
| | - Yariv Brotman
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Alisdair R Fernie
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
- Center of Plant System Biology and Biotechnology, 4000 Plovdiv, Bulgaria
| | - Anja Krieger-Liszkay
- Institute for Integrative Biology of the Cell, CEA Saclay, CNRS, University Paris-Sud, University Paris-Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Fred Beisson
- Aix Marseille University, CEA, CNRS, BIAM, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, F-13108 Saint Paul-Lez-Durance, France
| | - Gilles Peltier
- Aix Marseille University, CEA, CNRS, BIAM, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, F-13108 Saint Paul-Lez-Durance, France
| | - Yonghua Li-Beisson
- Aix Marseille University, CEA, CNRS, BIAM, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, F-13108 Saint Paul-Lez-Durance, France
| |
Collapse
|