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Sah SK, Fan J, Blanford J, Shanklin J, Xu C. Physiological Functions of Phospholipid:Diacylglycerol Acyltransferases. PLANT & CELL PHYSIOLOGY 2024; 65:863-871. [PMID: 37702708 DOI: 10.1093/pcp/pcad106] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/01/2023] [Accepted: 09/08/2023] [Indexed: 09/14/2023]
Abstract
Triacylglycerol (TAG) is among the most energy dense storage forms of reduced carbon in living systems. TAG metabolism plays critical roles in cellular energy balance, lipid homeostasis, cell growth and stress responses. In higher plants, microalgae and fungi, TAG is assembled by acyl-CoA-dependent and acyl-CoA-independent pathways catalyzed by diacylglycerol (DAG) acyltransferase and phospholipid:DAG acyltransferase (PDAT), respectively. This review contains a summary of the current understanding of the physiological functions of PDATs. Emphasis is placed on their role in lipid remodeling and lipid homeostasis in response to abiotic stress or perturbations in lipid metabolism.
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Affiliation(s)
- Saroj Kumar Sah
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jilian Fan
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jantana Blanford
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | | | - Changcheng Xu
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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Tatsumi K, Ichino T, Isaka N, Sugiyama A, Moriyoshi E, Okazaki Y, Higashi Y, Kajikawa M, Tsuji Y, Fukuzawa H, Toyooka K, Sato M, Ichi I, Shimomura K, Ohta H, Saito K, Yazaki K. Excretion of triacylglycerol as a matrix lipid facilitating apoplastic accumulation of a lipophilic metabolite shikonin. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:104-117. [PMID: 36223279 DOI: 10.1093/jxb/erac405] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 10/11/2022] [Indexed: 06/16/2023]
Abstract
Plants produce a large variety of lipophilic metabolites, many of which are secreted by cells and accumulated in apoplasts. These compounds often play a role to protect plants from environmental stresses. However, little is known about how these lipophilic compounds are secreted into apoplastic spaces. In this study, we used shikonin-producing cultured cells of Lithospermum erythrorhizon as an experimental model system to analyze the secretion of lipophilic metabolites, taking advantage of its high production rate and the clear inducibility in culture. Shikonin derivatives are lipophilic red naphthoquinone compounds that accumulate exclusively in apoplastic spaces of these cells and also in the root epidermis of intact plants. Microscopic analysis showed that shikonin is accumulated in the form of numerous particles on the cell wall. Lipidomic analysis showed that L. erythrorhizon cultured cells secrete an appreciable portion of triacylglycerol (24-38% of total triacylglycerol), composed predominantly of saturated fatty acids. Moreover, in vitro reconstitution assay showed that triacylglycerol encapsulates shikonin derivatives with phospholipids to form lipid droplet-like structures. These findings suggest a novel role for triacylglycerol as a matrix lipid, a molecular component involved in the secretion of specialized lipophilic metabolites.
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Affiliation(s)
- Kanade Tatsumi
- Research Institute for Sustainable Humanosphere, Kyoto University, Uji, 611-0011, Japan
| | - Takuji Ichino
- Research Institute for Sustainable Humanosphere, Kyoto University, Uji, 611-0011, Japan
| | - Natsumi Isaka
- Research Institute for Sustainable Humanosphere, Kyoto University, Uji, 611-0011, Japan
| | - Akifumi Sugiyama
- Research Institute for Sustainable Humanosphere, Kyoto University, Uji, 611-0011, Japan
| | - Eiko Moriyoshi
- Research Institute for Sustainable Humanosphere, Kyoto University, Uji, 611-0011, Japan
| | - Yozo Okazaki
- RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045, Japan
| | - Yasuhiro Higashi
- RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045, Japan
| | - Masataka Kajikawa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501, Japan
| | - Yoshinori Tsuji
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501, Japan
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501, Japan
| | - Kiminori Toyooka
- RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045, Japan
| | - Mayuko Sato
- RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045, Japan
| | - Ikuyo Ichi
- Institute for Human Life Innovation, Ochanomizu University, Tokyo 112-8610, Japan
| | - Koichiro Shimomura
- Graduate School of Life Sciences, Toyo University, Gunma, 374-0193, Japan
| | - Hiroyuki Ohta
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501, Japan
| | - Kazuki Saito
- RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045, Japan
- Plant Molecular Science Center, Chiba University, Chiba, 260-8675, Japan
| | - Kazufumi Yazaki
- Research Institute for Sustainable Humanosphere, Kyoto University, Uji, 611-0011, Japan
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Tsuji Y, Kinoshita A, Tsukahara M, Ishikawa T, Shinkawa H, Yamano T, Fukuzawa H. A YAK1-type protein kinase, triacylglycerol accumulation regulator 1, in the green alga Chlamydomonas reinhardtii is a potential regulator of cell division and differentiation into gametes during photoautotrophic nitrogen deficiency. J GEN APPL MICROBIOL 2022. [PMID: 36002293 DOI: 10.2323/jgam.2022.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Yet another kinase (YAK) 1 is a conserved eukaryotic protein kinase coordinating growth and development. We previously isolated a mutant of Chlamydomonas reinhardtii defective in the YAK1 ortholog triacylglycerol (TAG) accumulation regulator 1 (TAR1). The mutant tar1-1 displayed higher levels of chlorophyll, starch, TAG, and biomass than the parental strain C9 (renamed as C9-3) in photoautotrophic nitrogen (N)-deficient conditions. However, we found that the parental C9-3 showed faster chlorosis upon N-deficiency than the original C9 (C9-1) freshly recovered from cryopreservation, suggesting that C9-3 had acquired particular characteristics during long-term subculturing. To exclude phenotypes dependent on a particular parental strain, we newly created tar1 mutants from two wild-types, C9-1 and CC 125. Like tar1-1, the new tar1 mutants showed higher levels of chlorophyll and TAG/starch than the parental strain. Upon removal of N, Chlamydomonas cells divide once before ceasing further division. Previously, the single division after N-removal was arrested in tar1-1 in photomixotrophic conditions, but this phenotype was not observed in photoautotrophic conditions because of the particular characteristics of the parental C9-3. However, using C9- 1 and CC-125 as parental strains, we showed that cell division after N-removal was impaired in new tar1 mutants in photoautotrophic conditions. Consistent with the view that the division under N-deficiency is necessary for gametic differentiation, new tar1 mutants showed lower mating efficiency than the parental strains. Taken together, TAR1 was suggested to promote differentiation into gametes through the regulation of cell division in response to N-deficiency.
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Affiliation(s)
| | | | | | | | - Haruka Shinkawa
- Graduate Study of Biostudies, Kyoto University.,Present address: Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University
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Shinkawa H, Kajikawa M, Furuya T, Nishihama R, Tsukaya H, Kohchi T, Fukuzawa H. Protein Kinase MpYAK1 Is Involved in Meristematic Cell Proliferation, Reproductive Phase Change and Nutrient Signaling in the Liverwort Marchantia polymorpha. PLANT & CELL PHYSIOLOGY 2022; 63:1063-1077. [PMID: 35674121 DOI: 10.1093/pcp/pcac076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 05/09/2022] [Accepted: 06/07/2022] [Indexed: 06/15/2023]
Abstract
Plant growth and development are regulated by environmental factors, including nutrient availability and light conditions, via endogenous genetic signaling pathways. Phosphorylation-dependent protein modification plays a major role in the regulation of cell proliferation in stress conditions, and several protein kinases have been shown to function in response to nutritional status, including dual-specificity tyrosine phosphorylation-regulated kinases (DYRKs). Although DYRKs are widely conserved in eukaryotes, the physiological functions of DYRKs in land plants are still to be elucidated. In the liverwort Marchantia polymorpha, a model bryophyte, four putative genes encoding DYRK homologous proteins, each of which belongs to the subfamily yet another kinase 1 (Yak1), plant-specific DYRK, DYRK2, or pre-mRNA processing protein 4 kinase, were identified. MpYAK1-defective male and female mutant lines generated by the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated nuclease 9 (Cas9) system showed smaller sizes of thalli than did the wild-type plants and repressed cell divisions in the apical notch regions. The Mpyak1 mutants developed rhizoids from gemmae in the gemma cup before release. The Mpyak1 lines developed sexual organs even in non-inductive short-day photoperiod conditions supplemented with far-red light. In nitrogen (N)-deficient conditions, rhizoid elongation was inhibited in the Mpyak1 mutants. In conditions of aeration with 0.08% CO2 (v/v) and N depletion, Mpyak1 mutants accumulated higher levels of sucrose and lower levels of starch compared to the wild type. Transcriptomic analyses revealed that the expression of peroxidase genes was differentially affected by MpYAK1. These results suggest that MpYAK1 is involved in the maintenance of plant growth and developmental responses to light conditions and nutrient signaling.
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Affiliation(s)
- Haruka Shinkawa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502 Japan
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Ishikawa, 921-8836 Japan
| | - Masataka Kajikawa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502 Japan
- Faculty of Biology-Oriented Science and Technology, Kindai University, Wakayama, 649-6493 Japan
| | - Tomoyuki Furuya
- Graduate School of Science, University of Tokyo, Tokyo, 113-0033 Japan
- College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga, 525-8577 Japan
| | - Ryuichi Nishihama
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502 Japan
- Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, 278-8510 Japan
| | - Hirokazu Tsukaya
- Graduate School of Science, University of Tokyo, Tokyo, 113-0033 Japan
| | - Takayuki Kohchi
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502 Japan
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502 Japan
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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: 9] [Impact Index Per Article: 4.5] [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).
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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
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Metabolic Profiles Reveal Changes in the Leaves and Roots of Rapeseed (Brassica napus L.) Seedlings under Nitrogen Deficiency. Int J Mol Sci 2022; 23:ijms23105784. [PMID: 35628591 PMCID: PMC9142919 DOI: 10.3390/ijms23105784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 05/17/2022] [Accepted: 05/19/2022] [Indexed: 11/23/2022] Open
Abstract
Rapeseed (Brassica napus L.) is an important oil crop species and plays a crucial role in supplying edible oil worldwide. However, rapeseed production in the field is often severely inhibited due to nitrogen (N) deficiency. Metabolites play key roles in plant growth and resistance to environmental stress, but little is known about the differential synthesis and accumulation of metabolites underlying rapeseed adaptation to N deficiency. Here, we studied the phenotypic response and used LC–electrospray ionization (ESI), ESI–MS/MS, and widely untargeted metabolomic approaches to detect differences in rapeseed under normal N (HN) and N-deficient (LN) conditions. The results showed that N deficiency severely inhibited rapeseed shoot growth and promoted rapeseed root architectural changes under LN conditions. In total, 574 metabolites were detected, and there were 175 and 166 differentially accumulated metabolites in the leaves and roots between the HN and LN conditions, respectively. The significantly differentially accumulated metabolites were involved in four primary metabolic pathways, namely, sucrose, phenylalanine, amino acid, and tricarboxylic acid cycle metabolism. Notably, we found that plant hormones have distinct accumulation patterns in rapeseed and coordinate to play crucial roles in both maintaining growth and protecting against damage from plant disease under HN and LN conditions. Moreover, our results indicated that flavonoid compounds, especially anthocyanins and rutin, may play important roles in increasing root cell resistance to oxidative damage and soil pathogen infections. Overall, this work provides valuable information for understanding the overall metabolite changes in rapeseed under N deficiency conditions, which may be beneficial for improving and producing new varieties of rapeseed capable of high yields under low N conditions.
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Furuya T, Shinkawa H, Kajikawa M, Nishihama R, Kohchi T, Fukuzawa H, Tsukaya H. A plant-specific DYRK kinase DYRKP coordinates cell morphology in Marchantia polymorpha. JOURNAL OF PLANT RESEARCH 2021; 134:1265-1277. [PMID: 34549353 PMCID: PMC8514375 DOI: 10.1007/s10265-021-01345-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 09/01/2021] [Indexed: 05/31/2023]
Abstract
Dual-specificity tyrosine phosphorylation-regulated kinases (DYRKs) are activated via the auto-phosphorylation of conserved tyrosine residues in their activation loop during protein translation, and they then phosphorylate serine/threonine residues on substrates. The DYRK family is widely conserved in eukaryotes and is composed of six subgroups. In plant lineages, DYRK homologs are classified into four subgroups, DYRK2s, yet another kinase1s, pre-mRNA processing factor 4 kinases, and DYRKPs. Only the DYRKP subgroup is plant-specific and has been identified in a wide array of plant lineages, including land plants and green algae. It has been suggested that in Arabidopsis thaliana DYRKPs are involved in the regulation of centripetal nuclear positioning induced by dark light conditions. However, the molecular functions, such as kinase activity and the developmental and physiological roles of DYRKPs are poorly understood. Here, we focused on a sole DYRKP ortholog in the model bryophyte, Marchantia polymorpha, MpDYRKP. MpDYRKP has a highly conserved kinase domain located in the C-terminal region and shares common sequence motifs in the N-terminal region with other DYRKP members. To identify the roles of MpDYRKP in M. polymorpha, we generated loss-of-function Mpdyrkp mutants via genome editing. Mpdyrkp mutants exhibited abnormal, shrunken morphologies with less flattening in their vegetative plant bodies, thalli, and male reproductive organs, antheridial receptacles. The surfaces of the thalli in the Mpdyrkp mutants appeared uneven and disordered. Moreover, their epidermal cells were drastically altered to a narrower shape when compared to the wild type. These results suggest that MpDYRKP acts as a morphological regulator, which contributes to orderly tissue morphogenesis via the regulation of cell shape.
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Grants
- 19K21189 ministry of education, culture, sports, science and technology
- 20K15813 ministry of education, culture, sports, science and technology
- 17K07753 ministry of education, culture, sports, science and technology
- 16H04805 ministry of education, culture, sports, science and technology
- 25113002 ministry of education, culture, sports, science and technology
- 19H05672 ministry of education, culture, sports, science and technology
- 251113009 ministry of education, culture, sports, science and technology
- 25113001 ministry of education, culture, sports, science and technology
- 19H05675 ministry of education, culture, sports, science and technology
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Affiliation(s)
- Tomoyuki Furuya
- Graduate School of Science, The University of Tokyo, Tokyo, 113- 0033, Japan
- Graduate School of Science, Kobe University, Kobe, 657-8501, Japan
| | - Haruka Shinkawa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Ishikawa, 921-8836, Japan
| | - Masataka Kajikawa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
- Faculty of Biology-Oriented Science and Technology, Kindai University, Wakayama, 649-6493, Japan
| | - Ryuichi Nishihama
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
- Faculty of Science and Technology, Tokyo University of Science, Chiba, 278- 8510, Japan
| | - Takayuki Kohchi
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Hirokazu Tsukaya
- Graduate School of Science, The University of Tokyo, Tokyo, 113- 0033, Japan.
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Salomé PA, Merchant SS. Co-expression networks in Chlamydomonas reveal significant rhythmicity in batch cultures and empower gene function discovery. THE PLANT CELL 2021; 33:1058-1082. [PMID: 33793846 PMCID: PMC8226298 DOI: 10.1093/plcell/koab042] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 01/25/2021] [Indexed: 05/18/2023]
Abstract
The unicellular green alga Chlamydomonas reinhardtii is a choice reference system for the study of photosynthesis and chloroplast metabolism, cilium assembly and function, lipid and starch metabolism, and metal homeostasis. Despite decades of research, the functions of thousands of genes remain largely unknown, and new approaches are needed to categorically assign genes to cellular pathways. Growing collections of transcriptome and proteome data now allow a systematic approach based on integrative co-expression analysis. We used a dataset comprising 518 deep transcriptome samples derived from 58 independent experiments to identify potential co-expression relationships between genes. We visualized co-expression potential with the R package corrplot, to easily assess co-expression and anti-correlation between genes. We extracted several hundred high-confidence genes at the intersection of multiple curated lists involved in cilia, cell division, and photosynthesis, illustrating the power of our method. Surprisingly, Chlamydomonas experiments retained a significant rhythmic component across the transcriptome, suggesting an underappreciated variable during sample collection, even in samples collected in constant light. Our results therefore document substantial residual synchronization in batch cultures, contrary to assumptions of asynchrony. We provide step-by-step protocols for the analysis of co-expression across transcriptome data sets from Chlamydomonas and other species to help foster gene function discovery.
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Toyokawa C, Yamano T, Fukuzawa H. Pyrenoid Starch Sheath Is Required for LCIB Localization and the CO 2-Concentrating Mechanism in Green Algae. PLANT PHYSIOLOGY 2020; 182:1883-1893. [PMID: 32041908 PMCID: PMC7140920 DOI: 10.1104/pp.19.01587] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 01/24/2020] [Indexed: 05/09/2023]
Abstract
Aquatic photosynthetic organisms induce a CO2-concentrating mechanism (CCM) to overcome the difficulty of acquiring inorganic carbon under CO2-limiting conditions. As part of the CCM, the CO2-fixing enzyme Rubisco is enriched in the pyrenoid located in the chloroplast, and, in many green algae, several thick starch plates surround the pyrenoid to form a starch sheath. In Chlamydomonas reinhardtii, low-CO2-inducible protein B (LCIB), which is an essential factor for the CCM, displays altered cellular localization in response to a decrease in environmental CO2 concentration, moving from dispersed throughout the chloroplast stroma to around the pyrenoid. However, the mechanism behind LCIB migration remains poorly understood. Here, we report the characteristics of an Isoamylase1-less mutant (4-D1), which shows aberrant LCIB localization and starch sheath formation. Under very-low-CO2 conditions, 4-D1 showed retarded growth, lower photosynthetic affinities against inorganic carbon, and a decreased accumulation level of the HCO3 - transporter HLA3. The aberrant localization of LCIB was also observed in another starch-sheathless mutant sta11-1, but not in sta2-1, which possesses a thinned starch sheath. These results suggest that the starch sheath around the pyrenoid is required for the correct localization of LCIB and for the operation of CCM.
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Affiliation(s)
- Chihana Toyokawa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Takashi Yamano
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
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10
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Kajikawa M, Fukuzawa H. Algal Autophagy Is Necessary for the Regulation of Carbon Metabolism Under Nutrient Deficiency. FRONTIERS IN PLANT SCIENCE 2020; 11:36. [PMID: 32117375 PMCID: PMC7012896 DOI: 10.3389/fpls.2020.00036] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 01/13/2020] [Indexed: 05/04/2023]
Abstract
Autophagy is a mechanism to recycle intracellular constituents such as amino acids and other carbon- and nitrogen (N)-containing compounds. Although autophagy-related (ATG) genes required for autophagy are encoded by many algal genomes, their functional importance in microalgae in nutrient-deficiency has not been appraised using ATG-defective mutants. Recently, by characterization of an insertional mutant of the ATG8 encoding a ubiquitin-like protein indispensable for autophagosome formation in a green alga Chlamydomonas reinhardtii, we have provided evidence that supports the following notions. ATG8 protein is required for the degradation of lipid droplets and triacylglycerol (TAG) triggered by resupply of N to cell culture in N-deficient conditions. ATG8 protein is also necessary for starch accumulation under phosphorus-deficient conditions. Algal autophagy is not necessary for inheritance of chloroplast and mitochondrial genomes. In this review, we discuss the physiological roles of algal autophagy associated with nutrient deficiency revealed by the genetic and biochemical analyses using disruption mutants and reagents that inhibit the fatty acid biosynthesis and vacuolar H+-ATPase.
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Mao X, Lao Y, Sun H, Li X, Yu J, Chen F. Time‑resolved transcriptome analysis during transitions of sulfur nutritional status provides insight into triacylglycerol (TAG) and astaxanthin accumulation in the green alga Chromochloris zofingiensis. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:128. [PMID: 32695224 PMCID: PMC7367374 DOI: 10.1186/s13068-020-01768-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 07/11/2020] [Indexed: 05/03/2023]
Abstract
BACKGROUND Chromochloris zofingiensis, an oleaginous microalga, is a promising feedstock for the co-production of triacylglycerol (TAG)-based biodiesel and the high-value product astaxanthin. To reveal the molecular mechanism of TAG and astaxanthin biosynthesis during transitions of sulfur nutritional status, namely sulfur-starvation (SS) and sulfur-replenishment (SR), the physiological responses and the transcriptomic dynamics of C. zofingiensis were examined. RESULTS The results revealed a reversible TAG and astaxanthin accumulation under SS, which is correlated with the reduction of cell growth and protein content, indicating the reallocation of carbon. By correlating the data on the physiological and transcriptional responses to different sulfur nutritional status, a model for the underlying mechanism of TAG and astaxanthin accumulation in C. zofingiensis was postulated, which involved up-regulation of key genes including diacylglycerol acyltransferase (DGTT5) and beta-carotene ketolase (BKT1), increased energy and NADPH supply by elevating the tricarboxylic acid (TCA) cycle and the oxidative pentose phosphate (OPP) pathway, and the increased carbon precursors (pyruvate and acetyl-CoA) through central carbon metabolism. In addition, the net enhancement of the de novo biosynthesis of fatty acids and the re-direction of the terpenoid precursors toward the branch catalyzed by lycopene beta cyclase (LCYb) and BKT1 escalated the substrate availability for the biosynthesis of TAG and astaxanthin, respectively. CONCLUSIONS In this study, the time-resolved transcriptional analysis of C. zofingiensis under SS and SR conditions was reported for the first time to elucidate the regulatory roles of key enzymes, including DGTT5, BKT1 and LCYb, in the underlying mechanisms of TAG and astaxanthin accumulation.
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Affiliation(s)
- Xuemei Mao
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060 China
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060 China
- Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, 518060 China
| | - Yongmin Lao
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060 China
- Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, 518060 China
| | - Han Sun
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060 China
| | - Xiaojie Li
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060 China
- Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, 518060 China
| | - Jianfeng Yu
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060 China
- Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, 518060 China
| | - Feng Chen
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060 China
- Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, 518060 China
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12
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Colina F, Carbó M, Meijón M, Cañal MJ, Valledor L. Low UV-C stress modulates Chlamydomonas reinhardtii biomass composition and oxidative stress response through proteomic and metabolomic changes involving novel signalers and effectors. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:110. [PMID: 32577129 PMCID: PMC7305600 DOI: 10.1186/s13068-020-01750-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 06/11/2020] [Indexed: 05/06/2023]
Abstract
BACKGROUND The exposure of microalgae and plants to low UV-C radiation dosages can improve their biomass composition and stress tolerance. Despite UV-C sharing these effects with UV-A/B but at much lower dosages, UV-C sensing and signal mechanisms are still mostly unknown. Thus, we have described and integrated the proteometabolomic and physiological changes occurring in Chlamydomonas reinhardtii-a simple Plantae model-into the first 24 h after a short and low-intensity UV-C irradiation in order to reconstruct the microalgae response system to this stress. RESULTS The microalgae response was characterized by increased redox homeostasis, ROS scavenging and protein damage repair/avoidance elements. These processes were upregulated along with others related to the modulation of photosynthetic electron flux, carbon fixation and C/N metabolism. These changes, attributed to either direct UV-C-, ROS- or redox unbalances-associated damage, trigger a response process involving novel signaling intermediaries and effectors such as the translation modulator FAP204, a PP2A-like protein and a novel DYRK kinase. These elements were found linked to the modulation of Chlamydomonas biomass composition (starch accumulation) and proliferation, within an UV-C response probably modulated by different epigenetic factors. CONCLUSION Chosen multiomics integration approach was able to describe many fast changes, including biomass composition and ROS stress tolerance, as a response to a low-intensity UV-C stress. Moreover, the employed omics and systems biology approach placed many previously unidentified protein and metabolites at the center of these changes. These elements would be promising targets for the characterization of this stress response in microalgae and plants and the engineering of more productive microalgae strains.
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Affiliation(s)
- Francisco Colina
- Plant Physiology, Department of Organisms and Systems Biology and University Institute of Biotechnology of Asturias (IUBA), University of Oviedo, Oviedo, Spain
| | - María Carbó
- Plant Physiology, Department of Organisms and Systems Biology and University Institute of Biotechnology of Asturias (IUBA), University of Oviedo, Oviedo, Spain
| | - Mónica Meijón
- Plant Physiology, Department of Organisms and Systems Biology and University Institute of Biotechnology of Asturias (IUBA), University of Oviedo, Oviedo, Spain
| | - María Jesús Cañal
- Plant Physiology, Department of Organisms and Systems Biology and University Institute of Biotechnology of Asturias (IUBA), University of Oviedo, Oviedo, Spain
| | - Luis Valledor
- Plant Physiology, Department of Organisms and Systems Biology and University Institute of Biotechnology of Asturias (IUBA), University of Oviedo, Oviedo, Spain
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13
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Akgül F. Effects of nitrogen concentration on growth, biomass, and biochemical composition of Desmodesmus communis (E. Hegewald) E. Hegewald. Prep Biochem Biotechnol 2019; 50:98-105. [PMID: 31809237 DOI: 10.1080/10826068.2019.1697884] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Nitrogen, being one of the building blocks of biomacromolecules, is an important nutrient for microalgae growth. Nitrogen availability alters the growth and biochemical composition of microalgae. We investigated the effects of different nitrogen concentrations on specific growth rate (SGR), biomass productivity (BP), total protein and lipid content and amino acid and fatty acid composition of Desmodesmus communis. Nitrogen deficiency increased algal growth and changed the lipid amount and composition. The maximum growth and BP were detected in 75% N-medium. The highest total protein and lipid amount were detected in 50% N- and 75% N-media, respectively. Amino acid and fatty acid compositions of samples varied widely depending on the nutrient concentrations. The amount of unsaturated fatty acid (USFAs) was higher than saturated fatty acid (SFAs) and Linolenic acid percentage is higher than the limit of European standards in all media. The data reported here provide important contributions how nitrogen scarcity and abundance affect the growth and biochemical content of microalgae and this information can further be utilized in culture optimization in studies aimed at microalgae production for biofuels.
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Affiliation(s)
- Füsun Akgül
- Faculty of Science and Arts, Department of Molecular Biology and Genetics, Mehmet Akif Ersoy University, Burdur, Turkey
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14
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Park S, Nguyen THT, Jin E. Improving lipid production by strain development in microalgae: Strategies, challenges and perspectives. BIORESOURCE TECHNOLOGY 2019; 292:121953. [PMID: 31405625 DOI: 10.1016/j.biortech.2019.121953] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 05/16/2023]
Abstract
Over the past decade, the number of original articles and reviews presenting microalgae as a promising feedstock for biodiesel has increased tremendously. Many improvements of microalgae have been achieved through selection and strain development for industrial applications. However, the large-scale production of lipids for commercialization is not yet realistic because the production is still much more expensive than that of agricultural products. This review summarizes recent research on the induction of lipid biosynthesis in microalgae and the various strategies of genetic and metabolic engineering for enhancing lipid production. Strain engineering targets are proposed based on these strategies. To address current limitations of strain engineering for lipid production, this review provides insights on recent engineering strategies based on molecular tools and methods, and also discusses further perspectives.
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Affiliation(s)
- Seunghye Park
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Republic of Korea
| | - Thu Ha Thi Nguyen
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Republic of Korea
| | - EonSeon Jin
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Republic of Korea.
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15
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Prioretti L, Carriere F, Field B, Avilan L, Montané MH, Menand B, Gontero B. Targeting TOR signaling for enhanced lipid productivity in algae. Biochimie 2019; 169:12-17. [PMID: 31265860 DOI: 10.1016/j.biochi.2019.06.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 06/26/2019] [Indexed: 01/21/2023]
Abstract
Microalgae can produce large quantities of triacylglycerols (TAGs) and other neutral lipids that are suitable for making biofuels and as feedstocks for green chemistry. However, TAGs accumulate under stress conditions that also stop growth, leading to a trade-off between biomass production and TAG yield. Recently, in the model marine diatom Phaeodactylum tricornutum it was shown that inhibition of the target of rapamycin (TOR) kinase boosts lipid productivity by promoting TAG production without stopping growth. We believe that basic knowledge in this emerging field is required to develop innovative strategies to improve neutral lipid accumulation in oleaginous microalgae. In this minireview, we discuss current research on the TOR signaling pathway with a focus on its control on lipid homeostasis. We first provide an overview of the well characterized roles of TOR in mammalian lipogenesis, adipogenesis and lipolysis. We then present evidence of a role for TOR in controlling TAG accumulation in microalgae, and draw parallels between the situation in animals, plants and microalgae to propose a model of TOR signaling for TAG accumulation in microalgae.
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Affiliation(s)
- Laura Prioretti
- Aix Marseille Univ, CNRS, BIP UMR 7281, 31 Chemin Joseph Aiguier, 13402, Marseille, Cedex 09, France
| | - Frédéric Carriere
- Aix Marseille Univ, CNRS, BIP UMR 7281, 31 Chemin Joseph Aiguier, 13402, Marseille, Cedex 09, France
| | - Ben Field
- Aix Marseille Univ, CEA, CNRS, UMR 7265 BIAM, 163 Avenue de Luminy, 13288, Marseille, France
| | - Luisana Avilan
- Aix Marseille Univ, CNRS, BIP UMR 7281, 31 Chemin Joseph Aiguier, 13402, Marseille, Cedex 09, France
| | - Marie-Hélène Montané
- Aix Marseille Univ, CEA, CNRS, UMR 7265 BIAM, 163 Avenue de Luminy, 13288, Marseille, France
| | - Benoît Menand
- Aix Marseille Univ, CEA, CNRS, UMR 7265 BIAM, 163 Avenue de Luminy, 13288, Marseille, France.
| | - Brigitte Gontero
- Aix Marseille Univ, CNRS, BIP UMR 7281, 31 Chemin Joseph Aiguier, 13402, Marseille, Cedex 09, France.
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16
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Kong F, Yamaoka Y, Ohama T, Lee Y, Li-Beisson Y. Molecular Genetic Tools and Emerging Synthetic Biology Strategies to Increase Cellular Oil Content in Chlamydomonas reinhardtii. PLANT & CELL PHYSIOLOGY 2019; 60:1184-1196. [PMID: 30715500 DOI: 10.1093/pcp/pcz022] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 01/18/2019] [Indexed: 05/26/2023]
Abstract
Microalgae constitute a highly diverse group of eukaryotic and photosynthetic microorganisms that have developed extremely efficient systems for harvesting and transforming solar energy into energy-rich molecules such as lipids. Although microalgae are considered to be one of the most promising platforms for the sustainable production of liquid oil, the oil content of these organisms is naturally low, and algal oil production is currently not economically viable. Chlamydomonas reinhardtii (Chlamydomonas) is an established algal model due to its fast growth, high transformation efficiency, and well-understood physiology and to the availability of detailed genome information and versatile molecular tools for this organism. In this review, we summarize recent advances in the development of genetic manipulation tools for Chlamydomonas, from gene delivery methods to state-of-the-art genome-editing technologies and fluorescent dye-based high-throughput mutant screening approaches. Furthermore, we discuss practical strategies and toolkits that enhance transgene expression, such as choice of expression vector and background strain. We then provide examples of how advanced genetic tools have been used to increase oil content in Chlamydomonas. Collectively, the current literature indicates that microalgal oil content can be increased by overexpressing key enzymes that catalyze lipid biosynthesis, blocking lipid degradation, silencing metabolic pathways that compete with lipid biosynthesis and modulating redox state. The tools and knowledge generated through metabolic engineering studies should pave the way for developing a synthetic biological approach to enhance lipid productivity in microalgae.
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Affiliation(s)
- Fantao Kong
- Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Pohang, Korea
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, China
| | - Yasuyo Yamaoka
- Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Pohang, Korea
| | - Takeshi Ohama
- School of Environmental Science and Engineering, Kochi University of Technology (KUT), Tosayamada, Kochi, Japan
| | - Youngsook Lee
- Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Pohang, Korea
- Department of Life Science, Pohang University of Science and Technology, Pohang, Korea
| | - Yonghua Li-Beisson
- Aix-Marseille Univ., CEA, CNRS, BIAM, UMR7265, CEA Cadarache, Saint-Paul-lez Durance F, France
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17
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Kang W, Li X, Sun A, Yu F, Hu X. Study of the Persistence of the Phytotoxicity Induced by Graphene Oxide Quantum Dots and of the Specific Molecular Mechanisms by Integrating Omics and Regular Analyses. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:3791-3801. [PMID: 30870590 DOI: 10.1021/acs.est.8b06023] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Although increasing attention has been paid to the nanotoxicity of graphene oxide quantum dots (GOQDs) due to their broad range of applications, the persistence and recoverability associated with GOQDs had been widely ignored. Interestingly, stress-response hormesis for algal growth was observed for Chlorella vulgaris as a single-celled model organism. Few physiological parameters, such as algal density, plasmolysis, and levels of reactive oxygen species, exhibited facile recovery. In contrast, the effects on chlorophyll a levels, permeability, and starch grain accumulation exhibited persistent toxicity. In the exposure stage, the downregulation of genes related to unsaturated fatty acid biosynthesis, carotenoid biosynthesis, phenylpropanoid biosynthesis, and binding contributed to toxic effects on photosynthesis. In the recovery stage, downregulation of genes related to the cis-Golgi network, photosystem I, photosynthetic membrane, and thylakoid was linked to the persistence of toxic effects on photosynthesis. The upregulated galactose metabolism and downregulated aminoacyl-tRNA biosynthesis also indicated toxicity persistence in the recovery stage. The downregulation and upregulation of phenylalanine metabolism in the exposure and recovery stages, respectively, reflected the tolerance of the algae to GOQDs. The present study highlights the importance of studying nanotoxicity by elucidation of stress and recovery patterns with metabolomics and transcriptomics.
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Affiliation(s)
- Weilu Kang
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering , Nankai University , Tianjin 300350 , P. R. China
| | - Xiaokang Li
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering , Nankai University , Tianjin 300350 , P. R. China
| | - Anqi Sun
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering , Nankai University , Tianjin 300350 , P. R. China
| | - Fubo Yu
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering , Nankai University , Tianjin 300350 , P. R. China
| | - Xiangang Hu
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering , Nankai University , Tianjin 300350 , P. R. China
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18
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Shinkawa H, Kajikawa M, Nomura Y, Ogura M, Sawaragi Y, Yamano T, Nakagami H, Sugiyama N, Ishihama Y, Kanesaki Y, Yoshikawa H, Fukuzawa H. Algal Protein Kinase, Triacylglycerol Accumulation Regulator 1, Modulates Cell Viability and Gametogenesis in Carbon/Nitrogen-Imbalanced Conditions. PLANT & CELL PHYSIOLOGY 2019; 60:916-930. [PMID: 30668822 DOI: 10.1093/pcp/pcz010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 01/08/2019] [Indexed: 05/20/2023]
Abstract
Nutrient-deprived microalgae accumulate triacylglycerol (TAG) in lipid droplets. A dual-specificity tyrosine phosphorylation-regulated kinase, TAG accumulation regulator 1 (TAR1) has been shown to be required for acetate-dependent TAG accumulation and the degradation of chlorophyll and photosynthesis-related proteins in photomixotrophic nitrogen (N)-deficient conditions (Kajikawa et�al. 2015). However, this previous report only examined particular condition. Here, we report that in photoautotrophic N-deficient conditions, tar1-1 cells, with a mutation in the TAR1 gene, maintained higher levels of cell viability and lower levels of hydrogen peroxide generation and accumulated higher levels of TAG and starch compared with those of wild type (WT) cells with bubbling of air containing 5% carbon dioxide. Transcriptomic analyses suggested that genes involved in the scavenging of reactive oxygen species are not repressed in tar1-1 cells. In contrast, the mating efficiency and mRNA levels of key regulatory genes for gametogenesis, MID, MTD and FUS, were suppressed in tar1-1 cells. Among the TAR1-dependent phosphopeptides deduced by phosphoproteomic analysis, protein kinases and enzymes related to N assimilation and carbon (C) metabolism are of particular interest. Characterization of these putative downstream factors may elucidate the molecular pathway whereby TAR1 mediates cellular propagation and C and N metabolism in C/N-imbalanced stress conditions.
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Affiliation(s)
- Haruka Shinkawa
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | | | - Yuko Nomura
- RIKEN Center for Sustainable Resource Science, Kanagawa, 230-0045 Japan
| | - Mayu Ogura
- Graduate School of Pharmaceutical Science, Kyoto University, Kyoto, 606-8501 Japan
| | - Yuri Sawaragi
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Takashi Yamano
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Hirofumi Nakagami
- RIKEN Center for Sustainable Resource Science, Kanagawa, 230-0045 Japan
| | - Naoyuki Sugiyama
- Graduate School of Pharmaceutical Science, Kyoto University, Kyoto, 606-8501 Japan
| | - Yasushi Ishihama
- Graduate School of Pharmaceutical Science, Kyoto University, Kyoto, 606-8501 Japan
| | - Yu Kanesaki
- NODAI Genome Research Center, Tokyo University of Agriculture, Tokyo, 156-8502 Japan
| | - Hirofumi Yoshikawa
- Department of Bioscience, Tokyo University of Agriculture, Tokyo, 156-8502 Japan
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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19
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Sun XM, Ren LJ, Zhao QY, Ji XJ, Huang H. Enhancement of lipid accumulation in microalgae by metabolic engineering. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:552-566. [DOI: 10.1016/j.bbalip.2018.10.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/30/2018] [Accepted: 10/05/2018] [Indexed: 01/08/2023]
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20
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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.
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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
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21
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Barrada A, Djendli M, Desnos T, Mercier R, Robaglia C, Montané MH, Menand B. A TOR-YAK1 signaling axis controls cell cycle, meristem activity and plant growth in Arabidopsis. Development 2019; 146:dev.171298. [PMID: 30705074 DOI: 10.1242/dev.171298] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 01/14/2019] [Indexed: 01/20/2023]
Abstract
TARGET OF RAPAMYCIN (TOR) is a conserved eukaryotic phosphatidylinositol-3-kinase-related kinase that plays a major role in regulating growth and metabolism in response to environment in plants. We performed a genetic screen for Arabidopsis ethylmethane sulfonate mutants resistant to the ATP-competitive TOR inhibitor AZD-8055 to identify new components of the plant TOR pathway. We found that loss-of-function mutants of the DYRK (dual specificity tyrosine phosphorylation regulated kinase)/YAK1 kinase are resistant to AZD-8055 and, reciprocally, that YAK1 overexpressors are hypersensitive to AZD-8055. Significantly, these phenotypes were conditional on TOR inhibition, positioning YAK1 activity downstream of TOR. We further show that the ATP-competitive DYRK1A inhibitor pINDY phenocopies YAK1 loss of function. Microscopy analysis revealed that YAK1 functions to repress meristem size and induce differentiation. We show that YAK1 represses cyclin expression in the different zones of the root meristem and that YAK1 is essential for TOR-dependent transcriptional regulation of the plant-specific SIAMESE-RELATED (SMR) cyclin-dependent kinase inhibitors in both meristematic and differentiating root cells. Thus, YAK1 is a major regulator of meristem activity and cell differentiation downstream of TOR.
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Affiliation(s)
- Adam Barrada
- Aix Marseille Université, CEA, CNRS, BIAM, Laboratoire de Génétique et Biophysique des Plantes, Marseille, France F-13009
| | - Meriem Djendli
- Aix Marseille Université, CEA, CNRS, BIAM, Laboratoire de Génétique et Biophysique des Plantes, Marseille, France F-13009
| | - Thierry Desnos
- Aix Marseille Univ, CEA, CNRS, BIAM, Laboratoire de Biologie du Développement des Plantes, Saint Paul-Lez-Durance, France F-13108
| | - Raphael Mercier
- Institut Jean-Pierre Bourgin (IJPB), Institut National de la Recherche Agronomique, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France
| | - Christophe Robaglia
- Aix Marseille Université, CEA, CNRS, BIAM, Laboratoire de Génétique et Biophysique des Plantes, Marseille, France F-13009
| | - Marie-Hélène Montané
- Aix Marseille Université, CEA, CNRS, BIAM, Laboratoire de Génétique et Biophysique des Plantes, Marseille, France F-13009
| | - Benoît Menand
- Aix Marseille Université, CEA, CNRS, BIAM, Laboratoire de Génétique et Biophysique des Plantes, Marseille, France F-13009
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22
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Wang P, Zhang B, Zhang H, He Y, Ong CN, Yang J. Metabolites change of Scenedesmus obliquus exerted by AgNPs. J Environ Sci (China) 2019; 76:310-318. [PMID: 30528022 DOI: 10.1016/j.jes.2018.05.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 05/17/2018] [Accepted: 05/17/2018] [Indexed: 06/09/2023]
Abstract
With increasing emission of silver nanoparticles (AgNPs) into the environment, it is important to understand the effects of ambient concentration of AgNPs. The biological effects of AgNPs on Scenedesmus obliquus, a ubiquitous freshwater microalgae, was evaluated. AgNPs exerted a minor inhibitory effect at low doses. Non-targeted metabolomic studies were conducted to understand and analyze the effect of AgNPs on algal cells from a molecular perspective. During the 48 hr of exposure to AgNPs, 30 metabolites were identified, of which nine had significant changes compared to the control group. These include d-galactose, sucrose, and d-fructose. These carbohydrates are involved in the synthesis and repair of cell walls. Glycine, an important constituent amino acid of glutathione, increased with AgNP exposure concentration increasing, likely to counteract an increased intracellular oxidative stress. These results provide a new understanding of the toxicity effects and mechanism of AgNPs. These metabolites could be useful biomarkers for future research, employed in the early detection of environmental risk from AgNPs.
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Affiliation(s)
- Pu Wang
- School of Environmental Science & Engineering, Shanghai Jiaotong University, Shanghai 200240, China; School of Municipal and Environmental Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China.
| | - Bo Zhang
- School of Environmental Science & Engineering, Shanghai Jiaotong University, Shanghai 200240, China.
| | - Hui Zhang
- NUS Environmental Research Institute, National University of Singapore, Singapore 117597, Singapore
| | - Yiliang He
- School of Environmental Science & Engineering, Shanghai Jiaotong University, Shanghai 200240, China
| | - Choon Nam Ong
- NUS Environmental Research Institute, National University of Singapore, Singapore 117597, Singapore
| | - Jun Yang
- School of Municipal and Environmental Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
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23
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De Mia M, Lemaire SD, Choquet Y, Wollman FA. Nitric Oxide Remodels the Photosynthetic Apparatus upon S-Starvation in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2019; 179:718-731. [PMID: 30530737 PMCID: PMC6426411 DOI: 10.1104/pp.18.01164] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 11/20/2018] [Indexed: 05/02/2023]
Abstract
Many photosynthetic autotrophs have evolved responses that adjust their metabolism to limitations in nutrient availability. Here we report a detailed characterization of the remodeling of photosynthesis upon sulfur starvation under heterotrophy and photo-autotrophy in the green alga (Chlamydomonas reinhardtii). Photosynthetic inactivation under low light and darkness is achieved through specific degradation of Rubisco and cytochrome b 6 f and occurs only in the presence of reduced carbon in the medium. The process is likely regulated by nitric oxide (NO), which is produced 24 h after the onset of starvation, as detected with NO-sensitive fluorescence probes visualized by fluorescence microscopy. We provide pharmacological evidence that intracellular NO levels govern this degradation pathway: the addition of a NO scavenger decreases the rate of cytochrome b 6 f and Rubisco degradation, whereas NO donors accelerate the degradation. Based on our analysis of the relative contribution of the different NO synthesis pathways, we conclude that the NO2-dependent nitrate reductase-independent pathway is crucial for NO production under sulfur starvation. Our data argue for an active role for NO in the remodeling of thylakoid protein complexes upon sulfur starvation.
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Affiliation(s)
- Marcello De Mia
- Laboratoire de Physiologie Membranaire et Moléculaire du Chloroplaste, Centre National de la Recherche Scientifique, Sorbonne Université, Institut de Biologie Physico-Chimique, 75005 Paris, France
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Centre National de la Recherche Scientifique, Sorbonne Université, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Stéphane D Lemaire
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Centre National de la Recherche Scientifique, Sorbonne Université, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Yves Choquet
- Laboratoire de Physiologie Membranaire et Moléculaire du Chloroplaste, Centre National de la Recherche Scientifique, Sorbonne Université, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Francis-André Wollman
- Laboratoire de Physiologie Membranaire et Moléculaire du Chloroplaste, Centre National de la Recherche Scientifique, Sorbonne Université, Institut de Biologie Physico-Chimique, 75005 Paris, France
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24
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Li-Beisson Y, Thelen JJ, Fedosejevs E, Harwood JL. The lipid biochemistry of eukaryotic algae. Prog Lipid Res 2019; 74:31-68. [PMID: 30703388 DOI: 10.1016/j.plipres.2019.01.003] [Citation(s) in RCA: 175] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 02/06/2023]
Abstract
Algal lipid metabolism fascinates both scientists and entrepreneurs due to the large diversity of fatty acyl structures that algae produce. Algae have therefore long been studied as sources of genes for novel fatty acids; and, due to their superior biomass productivity, algae are also considered a potential feedstock for biofuels. However, a major issue in a commercially viable "algal oil-to-biofuel" industry is the high production cost, because most algal species only produce large amounts of oils after being exposed to stress conditions. Recent studies have therefore focused on the identification of factors involved in TAG metabolism, on the subcellular organization of lipid pathways, and on interactions between organelles. This has been accompanied by the development of genetic/genomic and synthetic biological tools not only for the reference green alga Chlamydomonas reinhardtii but also for Nannochloropsis spp. and Phaeodactylum tricornutum. Advances in our understanding of enzymes and regulatory proteins of acyl lipid biosynthesis and turnover are described herein with a focus on carbon and energetic aspects. We also summarize how changes in environmental factors can impact lipid metabolism and describe present and potential industrial uses of algal lipids.
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Affiliation(s)
- Yonghua Li-Beisson
- Aix-Marseille Univ, CEA, CNRS, BIAM, UMR7265, CEA Cadarache, Saint-Paul-lez Durance F-13108, France.
| | - Jay J Thelen
- Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, United States.
| | - Eric Fedosejevs
- Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, United States.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK.
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25
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Kajikawa M, Yamauchi M, Shinkawa H, Tanaka M, Hatano K, Nishimura Y, Kato M, Fukuzawa H. Isolation and Characterization of Chlamydomonas Autophagy-Related Mutants in Nutrient-Deficient Conditions. PLANT & CELL PHYSIOLOGY 2019; 60:126-138. [PMID: 30295899 DOI: 10.1093/pcp/pcy193] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 09/17/2018] [Indexed: 05/08/2023]
Abstract
Autophagy is a recycling system for amino acids and carbon- and nitrogen (N)-containing compounds. To date, the functional importance of autophagy in microalgae in nutrient-deficient conditions has not been evaluated by using autophagy-defective mutants. Here, we provide evidence which supports the following notions by characterizing an insertional mutant of the autophagy-related gene ATG8, encoding a ubiquitin-like protein necessary for the formation of the autophagosome in the green alga, Chlamydomonas reinhardtii. First, ATG8 is required for maintenance of cell survival and Chl content in N-, sulfur- and phosphate-deficient conditions. Secondly, ATG8 supports the degradation of triacylglycerol and lipid droplets after the resupply of N to cells cultured in N-limiting conditions. Thirdly, ATG8 is also necessary for accumulation of starch in phosphate-deficient conditions. Additionally, autophagy is not essential for maternal inheritance of the organelle genomes in gametogenesis.
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Affiliation(s)
| | - Marika Yamauchi
- Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo, Japan
| | - Haruka Shinkawa
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Manabu Tanaka
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Kyoko Hatano
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | | | - Misako Kato
- Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo, Japan
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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26
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Iwabuchi K, Ohnishi H, Tamura K, Fukao Y, Furuya T, Hattori K, Tsukaya H, Hara-Nishimura I. ANGUSTIFOLIA Regulates Actin Filament Alignment for Nuclear Positioning in Leaves. PLANT PHYSIOLOGY 2019; 179:233-247. [PMID: 30404821 PMCID: PMC6324246 DOI: 10.1104/pp.18.01150] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 10/24/2018] [Indexed: 05/03/2023]
Abstract
During dark adaptation, plant nuclei move centripetally toward the midplane of the leaf blade; thus, the nuclei on both the adaxial and abaxial sides become positioned at the inner periclinal walls of cells. This centripetal nuclear positioning implies that a characteristic cell polarity exists within a leaf, but little is known about the mechanism underlying this process. Here, we show that ANGUSTIFOLIA (AN) and ACTIN7 regulate centripetal nuclear positioning in Arabidopsis (Arabidopsis thaliana) leaves. Two mutants defective in the positioning of nuclei in the dark were isolated and designated as unusual nuclear positioning1 (unp1) and unp2 In the dark, nuclei of unp1 were positioned at the anticlinal walls of adaxial and abaxial mesophyll cells and abaxial pavement cells, whereas the nuclei of unp2 were positioned at the anticlinal walls of mesophyll and pavement cells on both the adaxial and abaxial sides. unp1 was caused by a dominant-negative mutation in ACTIN7, and unp2 resulted from a recessive mutation in AN Actin filaments in unp1 were fragmented and reduced in number, which led to pleiotropic defects in nuclear morphology, cytoplasmic streaming, and plant growth. The mutation in AN caused aberrant positioning of nuclei-associated actin filaments at the anticlinal walls. AN was detected in the cytosol, where it interacted physically with plant-specific dual-specificity tyrosine phosphorylation-regulated kinases (DYRKPs) and itself. The DYRK inhibitor (1Z)-1-(3-ethyl-5-hydroxy-2(3H)-benzothiazolylidene)-2-propanone significantly inhibited dark-induced nuclear positioning. Collectively, these results suggest that the AN-DYRKP complex regulates the alignment of actin filaments during centripetal nuclear positioning in leaf cells.
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Affiliation(s)
- Kosei Iwabuchi
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
- Faculty of Science and Engineering, Konan University, Kobe 658-8501, Japan
| | - Haruna Ohnishi
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Kentaro Tamura
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
- School of Food and Nutritional Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Yoichiro Fukao
- College of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan
| | - Tomoyuki Furuya
- Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan
| | - Koro Hattori
- Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan
| | - Hirokazu Tsukaya
- Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan
- Okazaki Institute for Integrative Bioscience, Okazaki 444-8787, Japan
| | - Ikuko Hara-Nishimura
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
- Faculty of Science and Engineering, Konan University, Kobe 658-8501, Japan
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27
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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.
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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
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28
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Liang MH, Wang L, Wang Q, Zhu J, Jiang JG. High-value bioproducts from microalgae: Strategies and progress. Crit Rev Food Sci Nutr 2018; 59:2423-2441. [PMID: 29676930 DOI: 10.1080/10408398.2018.1455030] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Microalgae have been considered as alternative sustainable resources for high-value bioproducts such as lipids (especially triacylglycerides [TAGs]), polyunsaturated fatty acids (PUFAs), and carotenoids, due to their relatively high photosynthetic efficiency, no arable land requirement, and ease of scale-up. It is of great significance to exploit microalgae for the production of high-value bioproducts. How to improve the content or productivity of specific bioproducts has become one of the most urgent challenges. In this review, we will describe high-value bioproducts from microalgae and their biosynthetic pathways (mainly for lipids, PUFAs, and carotenoids). Recent progress and strategies for the enhanced production of bioproducts from microalgae are also described in detail, and these strategies take advantages of optimized cultivation conditions with abiotic stress, chemical stress (addition of metabolic precursors, phytohormones, chemical inhibitors, and chemicals inducing oxidative stress response), and molecular approaches such as metabolic engineering, transcriptional engineering, and gene disruption strategies (mainly RNAi, antisense RNA, miRNA-based knockdown, and CRISPR/Cas9).
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Affiliation(s)
- Ming-Hua Liang
- a College of Food Science and Engineering, South China University of Technology , Guangzhou , China
| | - Ling Wang
- b School of Biotechnology, Jiangsu University of Science and Technology , Zhenjiang , China
| | - Qiming Wang
- c College of Bioscience and Biotechnology, Hunan Agricultural University , Changsha , China
| | - Jianhua Zhu
- b School of Biotechnology, Jiangsu University of Science and Technology , Zhenjiang , China.,c College of Bioscience and Biotechnology, Hunan Agricultural University , Changsha , China.,d Department of Plant Science and Landscape Architecture, University of Maryland , College Park , Maryland , USA
| | - Jian-Guo Jiang
- a College of Food Science and Engineering, South China University of Technology , Guangzhou , China
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29
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Yamazaki T, Konosu E, Takeshita T, Hirata A, Ota S, Kazama Y, Abe T, Kawano S. Independent regulation of the lipid and starch synthesis pathways by sulfate metabolites in the green microalga Parachlorella kessleri under sulfur starvation conditions. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.09.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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30
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Sun XM, Ren LJ, Zhao QY, Ji XJ, Huang H. Microalgae for the production of lipid and carotenoids: a review with focus on stress regulation and adaptation. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:272. [PMID: 30305845 PMCID: PMC6171298 DOI: 10.1186/s13068-018-1275-9] [Citation(s) in RCA: 167] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 09/26/2018] [Indexed: 05/04/2023]
Abstract
Microalgae have drawn great attention as promising sustainable source of lipids and carotenoids. Their lipid and carotenoids accumulation machinery can be trigged by the stress conditions such as nutrient limitation or exposure to the damaging physical factors. However, stressful conditions often adversely affect microalgal growth and cause oxidative damage to the cells, which can eventually reduce the yield of the desired products. To overcome these limitations, two-stage cultivation strategies and supplementation of growth-promoting agents have traditionally been utilized, but developing new highly adapted strains is theoretically the simplest strategy. In addition to genetic engineering, adaptive laboratory evolution (ALE) is frequently used to develop beneficial phenotypes in industrial microorganisms during long-term selection under specific stress conditions. In recent years, many studies have gradually introduced ALE as a powerful tool to improve the biological properties of microalgae, especially for improving the production of lipid and carotenoids. In this review, strategies for the manipulation of stress in microalgal lipids and carotenoids production are summarized and discussed. Furthermore, this review summarizes the overall state of ALE technology, including available selection pressures, methods, and their applications in microalgae for the improved production of lipids and carotenoids.
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Affiliation(s)
- Xiao-Man Sun
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816 People’s Republic of China
| | - Lu-Jing Ren
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816 People’s Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing, People’s Republic of China
| | - Quan-Yu Zhao
- School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816 People’s Republic of China
| | - Xiao-Jun Ji
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816 People’s Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing, People’s Republic of China
| | - He Huang
- School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816 People’s Republic of China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, No. 5 Xinmofan Road, Nanjing, 210009 People’s Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing, People’s Republic of China
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31
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Ramanan R, Tran QG, Cho DH, Jung JE, Kim BH, Shin SY, Choi SH, Liu KH, Kim DS, Lee SJ, Crespo JL, Lee HG, Oh HM, Kim HS. The Ancient Phosphatidylinositol 3-Kinase Signaling System Is a Master Regulator of Energy and Carbon Metabolism in Algae. PLANT PHYSIOLOGY 2018; 177:1050-1065. [PMID: 29769325 PMCID: PMC6053016 DOI: 10.1104/pp.17.01780] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 05/02/2018] [Indexed: 05/08/2023]
Abstract
Algae undergo a complete metabolic transformation under stress by arresting cell growth, inducing autophagy and hyper-accumulating biofuel precursors such as triacylglycerols and starch. However, the regulatory mechanisms behind this stress-induced transformation are still unclear. Here, we use biochemical, mutational, and "omics" approaches to demonstrate that PI3K signaling mediates the homeostasis of energy molecules and influences carbon metabolism in algae. In Chlamydomonas reinhardtii, the inhibition and knockdown (KD) of algal class III PI3K led to significantly decreased cell growth, altered cell morphology, and higher lipid and starch contents. Lipid profiling of wild-type and PI3K KD lines showed significantly reduced membrane lipid breakdown under nitrogen starvation (-N) in the KD. RNA-seq and network analyses showed that under -N conditions, the KD line carried out lipogenesis rather than lipid hydrolysis by initiating de novo fatty acid biosynthesis, which was supported by tricarboxylic acid cycle down-regulation and via acetyl-CoA synthesis from glycolysis. Remarkably, autophagic responses did not have primacy over inositide signaling in algae, unlike in mammals and vascular plants. The mutant displayed a fundamental shift in intracellular energy flux, analogous to that in tumor cells. The high free fatty acid levels and reduced mitochondrial ATP generation led to decreased cell viability. These results indicate that the PI3K signal transduction pathway is the metabolic gatekeeper restraining biofuel yields, thus maintaining fitness and viability under stress in algae. This study demonstrates the existence of homeostasis between starch and lipid synthesis controlled by lipid signaling in algae and expands our understanding of such processes, with biotechnological and evolutionary implications.
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Affiliation(s)
- Rishiram Ramanan
- Department of Environmental Science, School of Earth Science Systems, Central University of Kerala, Tejaswini Hills, Periya, Kasaragod 671316, Kerala, India
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Quynh-Giao Tran
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yuseong-gu, Daejeon 34141, Republic of Korea
- Department of Environmental Biotechnology, KRIBB School of Biotechnology, Korea University of Science and Technology, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Dae-Hyun Cho
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jae-Eun Jung
- Genome Research Center, KRIBB, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Byung-Hyuk Kim
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Sang-Yoon Shin
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yuseong-gu, Daejeon 34141, Republic of Korea
- Department of Environmental Biotechnology, KRIBB School of Biotechnology, Korea University of Science and Technology, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Sae-Hae Choi
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Kwang-Hyeon Liu
- College of Pharmacy, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Dae-Soo Kim
- Genome Research Center, KRIBB, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Seon-Jin Lee
- Biomedical Genomics Research Center, KRIBB, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - José L Crespo
- Instituto de Bioquimica Vegetal y Fotosintesis, Consejo Superior de Investigaciones Cientificas, Universidad de Sevilla, Seville 41092, Spain
| | - Hee-Gu Lee
- Biomedical Genomics Research Center, KRIBB, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Hee-Mock Oh
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yuseong-gu, Daejeon 34141, Republic of Korea
- Department of Environmental Biotechnology, KRIBB School of Biotechnology, Korea University of Science and Technology, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Hee-Sik Kim
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yuseong-gu, Daejeon 34141, Republic of Korea
- Department of Environmental Biotechnology, KRIBB School of Biotechnology, Korea University of Science and Technology, Yuseong-gu, Daejeon 34141, Republic of Korea
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32
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Du ZY, Lucker BF, Zienkiewicz K, Miller TE, Zienkiewicz A, Sears BB, Kramer DM, Benning C. Galactoglycerolipid Lipase PGD1 Is Involved in Thylakoid Membrane Remodeling in Response to Adverse Environmental Conditions in Chlamydomonas. THE PLANT CELL 2018; 30:447-465. [PMID: 29437989 PMCID: PMC5868692 DOI: 10.1105/tpc.17.00446] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 01/25/2018] [Accepted: 02/03/2018] [Indexed: 05/20/2023]
Abstract
Photosynthesis occurs in the thylakoid membrane, where the predominant lipid is monogalactosyldiacylglycerol (MGDG). As environmental conditions change, photosynthetic membranes have to adjust. In this study, we used a loss-of-function Chlamydomonas reinhardtii mutant deficient in the MGDG-specific lipase PGD1 (PLASTID GALACTOGLYCEROLIPID DEGRADATION1) to investigate the link between MGDG turnover, chloroplast ultrastructure, and the production of reactive oxygen species (ROS) in response to different adverse environmental conditions. The pgd1 mutant showed altered MGDG abundance and acyl composition and altered abundance of photosynthesis complexes, with an increased PSII/PSI ratio. Transmission electron microscopy showed hyperstacking of the thylakoid grana in the pgd1 mutant. The mutant also exhibited increased ROS production during N deprivation and high light exposure. Supplementation with bicarbonate or treatment with the photosynthetic electron transport blocker DCMU protected the cells against oxidative stress in the light and reverted chlorosis of pgd1 cells during N deprivation. Furthermore, exposure to stress conditions such as cold and high osmolarity induced the expression of PGD1, and loss of PGD1 in the mutant led to increased ROS production and inhibited cell growth. These findings suggest that PGD1 plays essential roles in maintaining appropriate thylakoid membrane composition and structure, thereby affecting growth and stress tolerance when cells are challenged under adverse conditions.
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Affiliation(s)
- Zhi-Yan Du
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Ben F Lucker
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Krzysztof Zienkiewicz
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University, 37073 Goettingen, Germany
| | - Tarryn E Miller
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Agnieszka Zienkiewicz
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University, 37073 Goettingen, Germany
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan 48824
| | - Barbara B Sears
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - David M Kramer
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Christoph Benning
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
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33
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Huang WY, Wu YC, Pu HY, Wang Y, Jang GJ, Wu SH. Plant dual-specificity tyrosine phosphorylation-regulated kinase optimizes light-regulated growth and development in Arabidopsis. PLANT, CELL & ENVIRONMENT 2017; 40:1735-1747. [PMID: 28437590 DOI: 10.1111/pce.12977] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 04/10/2017] [Accepted: 04/10/2017] [Indexed: 06/07/2023]
Abstract
Light controls vegetative and reproductive development of plants. For a plant, sensing the light input properly ensures coordination with the ever-changing environment. Previously, we found that LIGHT-REGULATED WD1 (LWD1) and LWD2 regulate the circadian clock and photoperiodic flowering. Here, we identified Arabidopsis YET ANOTHER KINASE1 (AtYAK1), an evolutionarily conserved protein and a member of dual-specificity tyrosine phosphorylation-regulated kinases (DYRKs), as an interacting protein of LWDs. Our study revealed that AtYAK1 is an important regulator for various light responses, including the circadian clock, photomorphogenesis and reproductive development. AtYAK1 could antagonize the function of LWDs in regulating the circadian clock and photoperiodic flowering. By examining phenotypes of atyak1, we found that AtYAK1 regulated light-induced period-length shortening and photomorphogenic development. Moreover, AtYAK1 mediated plant fertility especially under inferior light conditions including low light and short-day length. This study discloses a new regulator connecting environmental light to plant growth.
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Affiliation(s)
- Wen-Yu Huang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei, 11529, Taiwan
- Graduate Institute of Biotechnology and Department of Life Sciences, National Chung Hsing University, Taichung, 402, Taiwan
| | - Yi-Chen Wu
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Hsin-Yi Pu
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Ying Wang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Geng-Jen Jang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan
- Institute of Plant Biology, National Taiwan University, Taipei, 106, Taiwan
| | - Shu-Hsing Wu
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei, 11529, Taiwan
- Graduate Institute of Biotechnology and Department of Life Sciences, National Chung Hsing University, Taichung, 402, Taiwan
- Biotechnology Center, National Chung Hsing University, Taichung, 402, Taiwan
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Du C, Zhang B, He Y, Hu C, Ng QX, Zhang H, Ong CN. Biological effect of aqueous C 60 aggregates on Scenedesmus obliquus revealed by transcriptomics and non-targeted metabolomics. JOURNAL OF HAZARDOUS MATERIALS 2017; 324:221-229. [PMID: 28340994 DOI: 10.1016/j.jhazmat.2016.10.052] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Revised: 10/14/2016] [Accepted: 10/22/2016] [Indexed: 06/06/2023]
Abstract
This work evaluated biological effect of nC60 on Scenedesmus obliquus. The cells were exposed to various concentrations of nC60 for 7days. Low-dose of nC60 was found to have a minor growth inhibitory effect. The transcriptomics and metabolomics were integrated to examine intricate molecular and cellular effects of nC60 on Scenedesmus obliquus. We found that Scenedesmus obliquus cells exposed to nC60 had several significant alterations in cellular transcription and biochemical processes. During the 7-day exposure to nC60, 2234 and 2,448 unigenes were differentially expressed by 0.1mg/L and 1mg/L nC60-treated groups compared with the control, including 2085 or 2247 up-regulated genes and 149 or 201 down-regulated genes, respectively. We successfully identified 22 metabolites, including 6 significantly changed metabolites, such as sucrose, d-glucose, and malic acid. The citrate cycle (TCA cycle) (ko00020) was the main target of both differentially expressed genes and metabolic change. However, accumulation of sucrose (end-product) could have induced feedback inhibition of photosynthesis in Scenedesmus obliquus, explaining the slight growth inhibition observed. The results provided a mechanistic understanding of the growth inhibition of nC60 toxicity. These genes and metabolites are useful biomarkers for future studies and offer new insights into the early detectable changes in Scenedesmus obliquus with nC60 exposure.
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Affiliation(s)
- Chunlei Du
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Bo Zhang
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
| | - Yiliang He
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Chaoyang Hu
- Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minghan District, Shanghai 200240, China
| | - Qin Xiang Ng
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Hui Zhang
- NUS Environmental Research Institute, National University of Singapore, Singapore117597, Singapore
| | - Choon Nam Ong
- NUS Environmental Research Institute, National University of Singapore, Singapore117597, Singapore
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35
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Roustan V, Bakhtiari S, Roustan PJ, Weckwerth W. Quantitative in vivo phosphoproteomics reveals reversible signaling processes during nitrogen starvation and recovery in the biofuel model organism Chlamydomonas reinhardtii. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:280. [PMID: 29209414 PMCID: PMC5704542 DOI: 10.1186/s13068-017-0949-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 11/01/2017] [Indexed: 05/22/2023]
Abstract
BACKGROUND Nitrogen deprivation and replenishment induces massive changes at the physiological and molecular level in the green alga Chlamydomonas reinhardtii, including reversible starch and lipid accumulation. Stress signal perception and acclimation involves transient protein phosphorylation. This study aims to provide the first experimental phosphoprotein dataset for the adaptation of C. reinhardtii during nitrogen depletion and recovery growth phases and its impact on lipid accumulation. RESULTS To decipher the signaling pathways involved in this dynamic process, we applied a label-free in vivo shotgun phosphoproteomics analysis on nitrogen-depleted and recovered samples. 1227 phosphopeptides belonging to 732 phosphoproteins were identified and quantified. 470 phosphopeptides showed a significant change across the experimental set-up. Multivariate statistics revealed the reversible phosphorylation process and the time/condition-dependent dynamic rearrangement of the phosphoproteome. Protein-protein interaction analysis of differentially regulated phosphoproteins identified protein kinases and phosphatases, such as DYRKP and an AtGRIK1 orthologue, called CDPKK2, as central players in the coordination of translational, photosynthetic, proteomic and metabolomic activity. Phosphorylation of RPS6, ATG13, and NNK1 proteins points toward a specific regulation of the TOR pathway under nitrogen deprivation. Differential phosphorylation pattern of several eukaryotic initiation factor proteins (EIF) suggests a major control on protein translation and turnover. CONCLUSION This work provides the first phosphoproteomics dataset obtained for Chlamydomonas responses to nitrogen availability, revealing multifactorial signaling pathways and their regulatory function for biofuel production. The reproducibility of the experimental set-up allows direct comparison with proteomics and metabolomics datasets and refines therefore the current model of Chlamydomonas acclimation to various nitrogen levels. Integration of physiological, proteomics, metabolomics, and phosphoproteomics data reveals three phases of acclimation to N availability: (i) a rapid response triggering starch accumulation as well as energy metabolism while chloroplast structure is conserved followed by (ii) chloroplast degradation combined with cell autophagy and lipid accumulation and finally (iii) chloroplast regeneration and cell growth activation after nitrogen replenishment. Plastid development seems to be further interconnected with primary metabolism and energy stress signaling in order to coordinate cellular mechanism to nitrogen availability stress.
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Affiliation(s)
- Valentin Roustan
- Department of Ecogenomics and Systems Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Shiva Bakhtiari
- Department of Ecogenomics and Systems Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Pierre-Jean Roustan
- Department of Ecogenomics and Systems Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Wolfram Weckwerth
- Department of Ecogenomics and Systems Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
- Vienna Metabolomics Center (VIME), University of Vienna, Vienna, Austria
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36
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Production of ricinoleic acid-containing monoestolide triacylglycerides in an oleaginous diatom, Chaetoceros gracilis. Sci Rep 2016; 6:36809. [PMID: 27830762 PMCID: PMC5103293 DOI: 10.1038/srep36809] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 10/21/2016] [Indexed: 12/24/2022] Open
Abstract
Ricinoleic acid (RA), a hydroxyl fatty acid, is suitable for medical and industrial uses and is produced in high-oil-accumulating organisms such as castor bean and the ergot fungus Claviceps. We report here the efficient production of RA in a transgenic diatom Chaetoceros gracilis expressing the fatty acid hydroxylase gene (CpFAH) from Claviceps purpurea. In transgenic C. gracilis, RA content increased at low temperatures, reaching 2.2 pg/cell when cultured for 7 d at 15 °C, without affecting cell growth, and was enhanced (3.3 pg/cell) by the co-expression of a palmitic acid-specific elongase gene. Most of the accumulated RA was linked with monoestolide triacylglycerol (ME TAG), in which one RA molecule was esterified to the α position of the glycerol backbone and was further esterified at its hydroxy group with a fatty acid or second RA moiety, or 1-OH TAG, in which RA was esterified to the glycerol backbone. Overall, 80% of RA was accumulated as ME TAGs. Furthermore, exogenous RA-methyl ester suppressed the growth of wild-type diatoms in a dose-dependent manner and was rapidly converted to ME TAG. These results suggest that C. gracilis masks the hydroxyl group and accumulates RA as the less-toxic ME TAG.
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37
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Couso I, Evans BS, Li J, Liu Y, Ma F, Diamond S, Allen DK, Umen JG. Synergism between Inositol Polyphosphates and TOR Kinase Signaling in Nutrient Sensing, Growth Control, and Lipid Metabolism in Chlamydomonas. THE PLANT CELL 2016; 28:2026-2042. [PMID: 27600537 PMCID: PMC5059802 DOI: 10.1105/tpc.16.00351] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 08/19/2016] [Accepted: 09/02/2016] [Indexed: 05/17/2023]
Abstract
The networks that govern carbon metabolism and control intracellular carbon partitioning in photosynthetic cells are poorly understood. Target of Rapamycin (TOR) kinase is a conserved growth regulator that integrates nutrient signals and modulates cell growth in eukaryotes, though the TOR signaling pathway in plants and algae has yet to be completely elucidated. We screened the unicellular green alga Chlamydomonas reinhardtii using insertional mutagenesis to find mutants that conferred hypersensitivity to the TOR inhibitor rapamycin. We characterized one mutant, vip1-1, that is predicted to encode a conserved inositol hexakisphosphate kinase from the VIP family that pyrophosphorylates phytic acid (InsP6) to produce the low abundance signaling molecules InsP7 and InsP8 Unexpectedly, the rapamycin hypersensitive growth arrest of vip1-1 cells was dependent on the presence of external acetate, which normally has a growth-stimulatory effect on Chlamydomonas. vip1-1 mutants also constitutively overaccumulated triacylglycerols (TAGs) in a manner that was synergistic with other TAG inducing stimuli such as starvation. vip1-1 cells had reduced InsP7 and InsP8, both of which are dynamically modulated in wild-type cells by TOR kinase activity and the presence of acetate. Our data uncover an interaction between the TOR kinase and inositol polyphosphate signaling systems that we propose governs carbon metabolism and intracellular pathways that lead to storage lipid accumulation.
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Affiliation(s)
| | - Bradley S Evans
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Jia Li
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Yu Liu
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Fangfang Ma
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Spencer Diamond
- Earth and Planetary Science, University of California, Berkeley, California 94720
| | - Doug K Allen
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
- Agricultural Research Service, U.S. Department of Agriculture, St. Louis, Missouri 63132
| | - James G Umen
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
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38
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Goncalves EC, Wilkie AC, Kirst M, Rathinasabapathi B. Metabolic regulation of triacylglycerol accumulation in the green algae: identification of potential targets for engineering to improve oil yield. PLANT BIOTECHNOLOGY JOURNAL 2016; 14:1649-60. [PMID: 26801206 PMCID: PMC5066758 DOI: 10.1111/pbi.12523] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 11/13/2015] [Accepted: 11/25/2015] [Indexed: 05/03/2023]
Abstract
The great need for more sustainable alternatives to fossil fuels has increased our research interests in algal biofuels. Microalgal cells, characterized by high photosynthetic efficiency and rapid cell division, are an excellent source of neutral lipids as potential fuel stocks. Various stress factors, especially nutrient-starvation conditions, induce an increased formation of lipid bodies filled with triacylglycerol in these cells. Here we review our knowledge base on glycerolipid synthesis in the green algae with an emphasis on recent studies on carbon flux, redistribution of lipids under nutrient-limiting conditions and its regulation. We discuss the contributions and limitations of classical and novel approaches used to elucidate the algal triacylglycerol biosynthetic pathway and its regulatory network in green algae. Also discussed are gaps in knowledge and suggestions for much needed research both on the biology of triacylglycerol accumulation and possible avenues to engineer improved algal strains.
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Affiliation(s)
- Elton C Goncalves
- Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Ann C Wilkie
- Soil and Water Science Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Matias Kirst
- School of Forestry, University of Florida, Gainesville, FL, USA
| | - Bala Rathinasabapathi
- Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
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39
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Goold HD, Nguyen HM, Kong F, Beyly-Adriano A, Légeret B, Billon E, Cuiné S, Beisson F, Peltier G, Li-Beisson Y. Whole Genome Re-Sequencing Identifies a Quantitative Trait Locus Repressing Carbon Reserve Accumulation during Optimal Growth in Chlamydomonas reinhardtii. Sci Rep 2016; 6:25209. [PMID: 27141848 PMCID: PMC4855234 DOI: 10.1038/srep25209] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 04/13/2016] [Indexed: 02/08/2023] Open
Abstract
Microalgae have emerged as a promising source for biofuel production. Massive oil and starch accumulation in microalgae is possible, but occurs mostly when biomass growth is impaired. The molecular networks underlying the negative correlation between growth and reserve formation are not known. Thus isolation of strains capable of accumulating carbon reserves during optimal growth would be highly desirable. To this end, we screened an insertional mutant library of Chlamydomonas reinhardtii for alterations in oil content. A mutant accumulating five times more oil and twice more starch than wild-type during optimal growth was isolated and named constitutive oil accumulator 1 (coa1). Growth in photobioreactors under highly controlled conditions revealed that the increase in oil and starch content in coa1 was dependent on light intensity. Genetic analysis and DNA hybridization pointed to a single insertional event responsible for the phenotype. Whole genome re-sequencing identified in coa1 a >200 kb deletion on chromosome 14 containing 41 genes. This study demonstrates that, 1), the generation of algal strains accumulating higher reserve amount without compromising biomass accumulation is feasible; 2), light is an important parameter in phenotypic analysis; and 3), a chromosomal region (Quantitative Trait Locus) acts as suppressor of carbon reserve accumulation during optimal growth.
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Affiliation(s)
- Hugh Douglas Goold
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France.,Faculty of Agriculture and the Environment, University of Sydney, Australia
| | - Hoa Mai Nguyen
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
| | - Fantao Kong
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
| | - Audrey Beyly-Adriano
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
| | - Bertrand Légeret
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
| | - Emmanuelle Billon
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
| | - Stéphan Cuiné
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
| | - Fred Beisson
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
| | - Gilles Peltier
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
| | - Yonghua Li-Beisson
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
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40
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Schulz-Raffelt M, Chochois V, Auroy P, Cuiné S, Billon E, Dauvillée D, Li-Beisson Y, Peltier G. Hyper-accumulation of starch and oil in a Chlamydomonas mutant affected in a plant-specific DYRK kinase. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:55. [PMID: 26958078 PMCID: PMC4782384 DOI: 10.1186/s13068-016-0469-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 02/19/2016] [Indexed: 05/08/2023]
Abstract
BACKGROUND Because of their high biomass productivity and their ability to accumulate high levels of energy-rich reserve compounds such as oils or starch, microalgae represent a promising feedstock for the production of biofuel. Accumulation of reserve compounds takes place when microalgae face adverse situations such as nutrient shortage, conditions which also provoke a stop in cell division, and down-regulation of photosynthesis. Despite growing interest in microalgal biofuels, little is known about molecular mechanisms controlling carbon reserve formation. In order to discover new regulatory mechanisms, and identify genes of interest to boost the potential of microalgae for biofuel production, we developed a forward genetic approach in the model microalga Chlamydomonas reinhardtii. RESULTS By screening an insertional mutant library on the ability of mutants to accumulate and re-mobilize reserve compounds, we isolated a Chlamydomonas mutant (starch degradation 1, std1) deficient for a dual-specificity tyrosine-phosphorylation-regulated kinase (DYRK). The std1 mutant accumulates higher levels of starch and oil than wild-type and maintains a higher photosynthetic activity under nitrogen starvation. Phylogenetic analysis revealed that this kinase (named DYRKP) belongs to a plant-specific subgroup of the evolutionarily conserved DYRK kinase family. Furthermore, hyper-accumulation of storage compounds occurs in std1 mostly under low light in photoautotrophic condition, suggesting that the kinase normally acts under conditions of low energy status to limit reserve accumulation. CONCLUSIONS The DYRKP kinase is proposed to act as a negative regulator of the sink capacity of photosynthetic cells that integrates nutrient and energy signals. Inactivation of the kinase strongly boosts accumulation of reserve compounds under photoautotrophic nitrogen deprivation and allows maintaining high photosynthetic activity. The DYRKP kinase therefore represents an attractive target for improving the energy density of microalgae or crop plants.
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Affiliation(s)
- Miriam Schulz-Raffelt
- />CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- />CNRS, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13108 Saint-Paul-lez-Durance, France
- />Aix Marseille Université, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13284 Marseille, France
- />Molecular Biotechnology and Systems Biology, TU Kaiserslautern, Paul-Ehrlich-Straße 23, 67663 Kaiserslautern, Germany
| | - Vincent Chochois
- />CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- />CNRS, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13108 Saint-Paul-lez-Durance, France
- />Aix Marseille Université, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13284 Marseille, France
- />Research School of Biology College of Medicine, Biology and Environment, Linneaus Building 134, The Australian National University, Canberra, ACT 2601 Australia
| | - Pascaline Auroy
- />CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- />CNRS, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13108 Saint-Paul-lez-Durance, France
- />Aix Marseille Université, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13284 Marseille, France
| | - Stéphan Cuiné
- />CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- />CNRS, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13108 Saint-Paul-lez-Durance, France
- />Aix Marseille Université, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13284 Marseille, France
| | - Emmanuelle Billon
- />CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- />CNRS, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13108 Saint-Paul-lez-Durance, France
- />Aix Marseille Université, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13284 Marseille, France
| | - David Dauvillée
- />UMR8576, CNRS, Université des Sciences et Technologies de Lille, 59655 Villeneuve d’Ascq, France
| | - Yonghua Li-Beisson
- />CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- />CNRS, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13108 Saint-Paul-lez-Durance, France
- />Aix Marseille Université, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13284 Marseille, France
| | - Gilles Peltier
- />CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- />CNRS, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13108 Saint-Paul-lez-Durance, France
- />Aix Marseille Université, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13284 Marseille, France
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41
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Goncalves EC, Koh J, Zhu N, Yoo MJ, Chen S, Matsuo T, Johnson JV, Rathinasabapathi B. Nitrogen starvation-induced accumulation of triacylglycerol in the green algae: evidence for a role for ROC40, a transcription factor involved in circadian rhythm. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 85:743-57. [PMID: 26920093 DOI: 10.1111/tpj.13144] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 02/05/2016] [Accepted: 02/15/2016] [Indexed: 05/24/2023]
Abstract
Microalgal triacylglycerol (TAG), a promising source of biofuel, is induced upon nitrogen starvation (-N), but the proteins and genes involved in this process are poorly known. We performed isobaric tagging for relative and absolute quantification (iTRAQ)-based quantitative proteomics to identify Chlorella proteins with modulated expression under short-term -N. Out of 1736 soluble proteins and 2187 membrane-associated proteins identified, 288 and 56, respectively, were differentially expressed under -N. Gene expression analysis on select genes confirmed the same direction of mRNA modulation for most proteins. The MYB-related transcription factor ROC40 was the most induced protein, with a 9.6-fold increase upon -N. In a previously generated Chlamydomonas mutant, gravimetric measurements of crude total lipids revealed that roc40 was impaired in its ability to increase the accumulation of TAG upon -N, and this phenotype was complemented when wild-type Roc40 was expressed. Results from radiotracer experiments were consistent with the roc40 mutant being comparable to the wild type in recycling membrane lipids to TAG but being impaired in additional de novo synthesis of TAG during -N stress. In this study we provide evidence to support the hypothesis that transcription factor ROC40 has a role in -N-induced lipid accumulation, and uncover multiple previously unknown proteins modulated by short-term -N in green algae.
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Affiliation(s)
- Elton C Goncalves
- Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611-0690, USA
| | - Jin Koh
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, 32610, USA
| | - Ning Zhu
- Department of Biology, Plant Molecular and Cellular Biology Program, Genetics Institute, University of Florida, Gainesville, FL, 32611, USA
| | - Mi-Jeong Yoo
- Department of Biology, Plant Molecular and Cellular Biology Program, Genetics Institute, University of Florida, Gainesville, FL, 32611, USA
| | - Sixue Chen
- Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611-0690, USA
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, 32610, USA
- Department of Biology, Plant Molecular and Cellular Biology Program, Genetics Institute, University of Florida, Gainesville, FL, 32611, USA
| | - Takuya Matsuo
- Center for Gene Research, Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan
| | - Jodie V Johnson
- Chemistry Department, University of Florida, Gainesville, FL, 32611, USA
| | - Bala Rathinasabapathi
- Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611-0690, USA
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Identification of gene transcripts involved in lipid biosynthesis in Chlamydomonas reinhardtii under nitrogen, iron and sulfur deprivation. World J Microbiol Biotechnol 2016; 32:55. [DOI: 10.1007/s11274-016-2008-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 01/04/2016] [Indexed: 10/22/2022]
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Li X, Zhang R, Patena W, Gang SS, Blum SR, Ivanova N, Yue R, Robertson JM, Lefebvre PA, Fitz-Gibbon ST, Grossman AR, Jonikas MC. An Indexed, Mapped Mutant Library Enables Reverse Genetics Studies of Biological Processes in Chlamydomonas reinhardtii. THE PLANT CELL 2016; 28:367-87. [PMID: 26764374 PMCID: PMC4790863 DOI: 10.1105/tpc.15.00465] [Citation(s) in RCA: 236] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 11/30/2015] [Accepted: 01/11/2016] [Indexed: 05/18/2023]
Abstract
The green alga Chlamydomonas reinhardtii is a leading unicellular model for dissecting biological processes in photosynthetic eukaryotes. However, its usefulness has been limited by difficulties in obtaining mutants in specific genes of interest. To allow generation of large numbers of mapped mutants, we developed high-throughput methods that (1) enable easy maintenance of tens of thousands of Chlamydomonas strains by propagation on agar media and by cryogenic storage, (2) identify mutagenic insertion sites and physical coordinates in these collections, and (3) validate the insertion sites in pools of mutants by obtaining >500 bp of flanking genomic sequences. We used these approaches to construct a stably maintained library of 1935 mapped mutants, representing disruptions in 1562 genes. We further characterized randomly selected mutants and found that 33 out of 44 insertion sites (75%) could be confirmed by PCR, and 17 out of 23 mutants (74%) contained a single insertion. To demonstrate the power of this library for elucidating biological processes, we analyzed the lipid content of mutants disrupted in genes encoding proteins of the algal lipid droplet proteome. This study revealed a central role of the long-chain acyl-CoA synthetase LCS2 in the production of triacylglycerol from de novo-synthesized fatty acids.
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Affiliation(s)
- Xiaobo Li
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Ru Zhang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Weronika Patena
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Spencer S Gang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Sean R Blum
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Nina Ivanova
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Rebecca Yue
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Jacob M Robertson
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Paul A Lefebvre
- Department of Plant Biology, University of Minnesota, St. Paul, Minnesota 55108
| | - Sorel T Fitz-Gibbon
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095
| | - Arthur R Grossman
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Martin C Jonikas
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
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