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Krishnan A, Cano M, Karns DA, Burch TA, Likhogrud M, Aqui M, Bailey S, Verruto J, Lambert W, Kuzminov F, Naghipor M, Wang Y, Ebmeier CC, Weissman JC, Posewitz MC. Simultaneous CAS9 editing of cp SRP43, LHCA6, and LHCA7 in Picochlorum celeri lowers chlorophyll levels and improves biomass productivity. PLANT DIRECT 2023; 7:e530. [PMID: 37711644 PMCID: PMC10497401 DOI: 10.1002/pld3.530] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 08/03/2023] [Accepted: 08/17/2023] [Indexed: 09/16/2023]
Abstract
High cellular pigment levels in dense microalgal cultures contribute to excess light absorption. To improve photosynthetic yields in the marine microalga Picochlorum celeri, CAS9 gene editing was used to target the molecular chaperone cpSRP43. Depigmented strains (>50% lower chlorophyll) were generated, with proteomics showing attenuated levels of most light harvesting complex (LHC) proteins. Gene editing generated two types of cpSRP43 transformants with distinct lower pigment phenotypes: (i) a transformant (Δsrp43) with both cpSRP43 diploid alleles modified to encode non-functional polypeptides and (ii) a transformant (STR30309) with a 3 nt in-frame insertion in one allele at the CAS9 cut site (non-functional second allele), leading to expression of a modified cpSRP43. STR30309 has more chlorophyll than Δsrp43 but substantially less than wild type. To further decrease light absorption by photosystem I in STR30309, CAS9 editing was used to stack in disruptions of both LHCA6 and LHCA7 to generate STR30843, which has higher (5-24%) productivities relative to wild type in solar-simulating bioreactors. Maximal productivities required frequent partial harvests throughout the day. For STR30843, exemplary diel bioreactor yields of ~50 g m-2 day-1 were attained. Our results demonstrate diel productivity gains in P. celeri by lowering pigment levels.
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Affiliation(s)
- Anagha Krishnan
- Department of ChemistryColorado School of MinesGoldenColoradoUSA
| | - Melissa Cano
- Department of ChemistryColorado School of MinesGoldenColoradoUSA
| | - Devin A. Karns
- Department of ChemistryColorado School of MinesGoldenColoradoUSA
| | - Tyson A. Burch
- Department of ChemistryColorado School of MinesGoldenColoradoUSA
| | - Maria Likhogrud
- ExxonMobil Technology and Engineering CompanyAnnandaleNew JerseyUSA
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Advances in Genetic Engineering in Improving Photosynthesis and Microalgal Productivity. Int J Mol Sci 2023; 24:ijms24031898. [PMID: 36768215 PMCID: PMC9915242 DOI: 10.3390/ijms24031898] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/10/2023] [Accepted: 01/16/2023] [Indexed: 01/21/2023] Open
Abstract
Even though sunlight energy far outweighs the energy required by human activities, its utilization is a key goal in the field of renewable energies. Microalgae have emerged as a promising new and sustainable feedstock for meeting rising food and feed demand. Because traditional methods of microalgal improvement are likely to have reached their limits, genetic engineering is expected to allow for further increases in the photosynthesis and productivity of microalgae. Understanding the mechanisms that control photosynthesis will enable researchers to identify targets for genetic engineering and, in the end, increase biomass yield, offsetting the costs of cultivation systems and downstream biomass processing. This review describes the molecular events that happen during photosynthesis and microalgal productivity through genetic engineering and discusses future strategies and the limitations of genetic engineering in microalgal productivity. We highlight the major achievements in manipulating the fundamental mechanisms of microalgal photosynthesis and biomass production, as well as promising approaches for making significant contributions to upcoming microalgal-based biotechnology.
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Redekop P, Sanz-Luque E, Yuan Y, Villain G, Petroutsos D, Grossman AR. Transcriptional regulation of photoprotection in dark-to-light transition-More than just a matter of excess light energy. SCIENCE ADVANCES 2022; 8:eabn1832. [PMID: 35658034 PMCID: PMC9166400 DOI: 10.1126/sciadv.abn1832] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 04/18/2022] [Indexed: 05/22/2023]
Abstract
In nature, photosynthetic organisms are exposed to different light spectra and intensities depending on the time of day and atmospheric and environmental conditions. When photosynthetic cells absorb excess light, they induce nonphotochemical quenching to avoid photodamage and trigger expression of "photoprotective" genes. In this work, we used the green alga Chlamydomonas reinhardtii to assess the impact of light intensity, light quality, photosynthetic electron transport, and carbon dioxide on induction of the photoprotective genes (LHCSR1, LHCSR3, and PSBS) during dark-to-light transitions. Induction (mRNA accumulation) occurred at very low light intensity and was independently modulated by blue and ultraviolet B radiation through specific photoreceptors; only LHCSR3 was strongly controlled by carbon dioxide levels through a putative enhancer function of CIA5, a transcription factor that controls genes of the carbon concentrating mechanism. We propose a model that integrates inputs of independent signaling pathways and how they may help the cells anticipate diel conditions and survive in a dynamic light environment.
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Affiliation(s)
- Petra Redekop
- Department of Plant Biology, The Carnegie Institution for Science, 260 Panama St, Stanford, CA 94305, USA
- Corresponding author. (E.S.-L.); (P.R.)
| | - Emanuel Sanz-Luque
- Department of Plant Biology, The Carnegie Institution for Science, 260 Panama St, Stanford, CA 94305, USA
- Department of Biochemistry and Molecular Biology, University of Cordoba, 14071 Cordoba, Spain
- Corresponding author. (E.S.-L.); (P.R.)
| | - Yizhong Yuan
- Université Grenoble Alpes, CNRS, CEA, INRAe, IRIG-LPCV, 38000 Grenoble, France
| | - Gaelle Villain
- Université Grenoble Alpes, CNRS, CEA, INRAe, IRIG-LPCV, 38000 Grenoble, France
| | - Dimitris Petroutsos
- Université Grenoble Alpes, CNRS, CEA, INRAe, IRIG-LPCV, 38000 Grenoble, France
| | - Arthur R. Grossman
- Department of Plant Biology, The Carnegie Institution for Science, 260 Panama St, Stanford, CA 94305, USA
- Department of Biology, Stanford University, Stanford, CA 94305, USA
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King SJ, Jerkovic A, Brown LJ, Petroll K, Willows RD. Synthetic biology for improved hydrogen production in Chlamydomonas reinhardtii. Microb Biotechnol 2022; 15:1946-1965. [PMID: 35338590 PMCID: PMC9249334 DOI: 10.1111/1751-7915.14024] [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: 11/24/2021] [Revised: 02/09/2022] [Accepted: 02/11/2022] [Indexed: 12/04/2022] Open
Abstract
Hydrogen is a clean alternative to fossil fuels. It has applications for electricity generation and transportation and is used for the manufacturing of ammonia and steel. However, today, H2 is almost exclusively produced from coal and natural gas. As such, methods to produce H2 that do not use fossil fuels need to be developed and adopted. The biological manufacturing of H2 may be one promising solution as this process is clean and renewable. Hydrogen is produced biologically via enzymes called hydrogenases. There are three classes of hydrogenases namely [FeFe], [NiFe] and [Fe] hydrogenases. The [FeFe] hydrogenase HydA1 from the model unicellular algae Chlamydomonas reinhardtii has been studied extensively and belongs to the A1 subclass of [FeFe] hydrogenases that have the highest turnover frequencies amongst hydrogenases (21,000 ± 12,000 H2 s−1 for CaHydA from Clostridium acetobutyliticum). Yet to date, limitations in C. reinhardtii H2 production pathways have hampered commercial scale implementation, in part due to O2 sensitivity of hydrogenases and competing metabolic pathways, resulting in low H2 production efficiency. Here, we describe key processes in the biogenesis of HydA1 and H2 production pathways in C. reinhardtii. We also summarize recent advancements of algal H2 production using synthetic biology and describe valuable tools such as high‐throughput screening (HTS) assays to accelerate the process of engineering algae for commercial biological H2 production.
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Affiliation(s)
- Samuel J King
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Ante Jerkovic
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Louise J Brown
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Kerstin Petroll
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Robert D Willows
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
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Gan Y, Kou Y, Yan F, Wang X, Wang H, Song X, Zhang M, Zhao X, Jia R, Ge H, Yang S. Comparative Transcriptome Profiling Analysis Reveals the Adaptive Molecular Mechanism of Yellow-Green Leaf in Rosa beggeriana 'Aurea'. FRONTIERS IN PLANT SCIENCE 2022; 13:845662. [PMID: 35401615 PMCID: PMC8987444 DOI: 10.3389/fpls.2022.845662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 02/10/2022] [Indexed: 05/08/2023]
Abstract
Rosa beggeriana 'Aurea' is a yellow-green leaf (yl) mutant and originated from Rosa beggeriana Schrenk by 60Co-γ irradiation, which is an important ornamental woody species. However, the molecular mechanism of the yl mutant remains unknown. Herein, comparative transcriptome profiling was performed between the yl type and normal green color type (WT) by RNA sequencing. A total of 3,372 significantly differentially expressed genes (DEGs) were identified, consisting of 1,585 upregulated genes and 1,787 downregulated genes. Genes that took part in metabolic of biological process (1,090), membrane of cellular component (728), catalytic (1,114), and binding of molecular function (840) were significantly different in transcription level. DEGs involved in chlorophyll biosynthesis, carotenoids biosynthesis, cutin, suberine, wax biosynthesis, photosynthesis, chloroplast development, photosynthesis-antenna proteins, photosystem I (PSI) and photosystem II (PSII) components, CO2 fixation, ribosomal structure, and biogenesis related genes were downregulated. Meanwhile, linoleic acid metabolism, siroheme biosynthesis, and carbon source of pigments biosynthesis through methylerythritol 4-phosphate (MEP) pathways were upregulated. Moreover, a total of 147 putative transcription factors were signification different expression, involving NAC, WRKY, bHLH, MYB and AP2/ERF, C2H2, GRAS, and bZIP family gene. Our results showed that the disturbed pigments biosynthesis result in yl color by altering the ratio of chlorophylls and carotenoids in yl mutants. The yl mutants may evoke other metabolic pathways to compensate for the photodamage caused by the insufficient structure and function of chloroplasts, such as enhanced MEP pathways and linoleic acid metabolism against oxidative stress. This research can provide a reference for the application of leaf color mutants in the future.
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Affiliation(s)
- Ying Gan
- National Center of China for Flowers Improvement, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yaping Kou
- National Center of China for Flowers Improvement, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Fei Yan
- National Center of China for Flowers Improvement, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaofei Wang
- National Center of China for Flowers Improvement, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
- College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao, China
| | - Hongqian Wang
- National Center of China for Flowers Improvement, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiangshang Song
- National Center of China for Flowers Improvement, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Min Zhang
- National Center of China for Flowers Improvement, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xin Zhao
- National Center of China for Flowers Improvement, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Ruidong Jia
- National Center of China for Flowers Improvement, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Hong Ge
- National Center of China for Flowers Improvement, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shuhua Yang
- National Center of China for Flowers Improvement, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
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Guo Z, Deng H, Li J, Liao R, Ma H. Optimized Classification of Suspended Particles in Seawater by Dense Sampling of Polarized Light Pulses. SENSORS 2021; 21:s21217344. [PMID: 34770652 PMCID: PMC8587070 DOI: 10.3390/s21217344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/30/2021] [Accepted: 11/03/2021] [Indexed: 11/16/2022]
Abstract
Suspended particles affect the state and vitality of the marine ecosystem. In situ probing and accurately classifying the suspended particles in seawater have an important impact on ecological research and environmental monitoring. Individual measurement of the optical polarization parameters scattered by the suspended particles has been proven to be a powerful tool to classify the particulate compositions in seawater. In previous works, the temporal polarized light pulses are sampled and averaged to evaluate the polarization parameters. In this paper, a method based on dense sampling of polarized light pulses is proposed and the experimental setup is built. The experimental results show that the dense sampling method optimizes the classification and increases the average accuracy by at least 16% than the average method. We demonstrate the feasibility of dense sampling method by classifying the multiple types of particles in mixed suspensions and show its excellent generalization ability by multi-classification of the particles. Additional analysis indicates that the dense sampling method basically takes advantage of the high-quality polarization parameters to optimize the classification performance. The above results suggest that the proposed dense sampling method has the potential to probe the suspended particles in seawater in red-tide early warning, as well as sediment and microplastics monitoring.
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Affiliation(s)
- Zhiming Guo
- Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (Z.G.); (H.D.); (J.L.)
| | - Hanbo Deng
- Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (Z.G.); (H.D.); (J.L.)
- Department of Biomedical Engineering, Tsinghua University, Beijing 100084, China
| | - Jiajin Li
- Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (Z.G.); (H.D.); (J.L.)
- Department of Biomedical Engineering, Tsinghua University, Beijing 100084, China
| | - Ran Liao
- Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (Z.G.); (H.D.); (J.L.)
- Guangdong Research Center of Polarization Imaging and Measurement Engineering Technology, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China;
- Shenzhen Key Laboratory of Marine IntelliSensing and Computation, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
- Correspondence: ; Tel.: +86-755-869-75-301
| | - Hui Ma
- Guangdong Research Center of Polarization Imaging and Measurement Engineering Technology, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China;
- Department of Physics, Tsinghua University, Beijing 100084, China
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7
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Banerjee S, Ray A, Das D. Optimization of Chlamydomonas reinhardtii cultivation with simultaneous CO 2 sequestration and biofuels production in a biorefinery framework. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 762:143080. [PMID: 33162147 DOI: 10.1016/j.scitotenv.2020.143080] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 10/01/2020] [Accepted: 10/12/2020] [Indexed: 06/11/2023]
Abstract
Algal biomass is regarded as a sustainable energy feedstock for the future. Enhancement of the biomass and metabolite production of microalgae increases the economic feasibility of the biofuel production process. The present study encompasses on bioethanol production from Chlamydomonas reinhardtii through a biorefinery approach. The biomass and carbohydrate productivity of C. reinhardtii UTEX 90 and CC 2656 were enhanced by optimizing the physico-chemical parameters. The following conditions were found suitable for the improvement of biomass and metabolite content of C. reinhardtii: pH 6.5-7.0, incubation temperature 30 °C, initial acetate and ammonium chloride concentration of 1.56 g L-1 and 100-200 mg L-1, respectively. Under the optimized operational condition biomass and carbohydrate productivity of C. reinhardtii UTEX 90 and CC 2656 were 512 mg L-1 d-1 & 266.24 mg L-1 d-1 and 364 mg L-1 d -1 & 163.80 mg L-1 d-1, respectively. The amount of CO2 sequestered during the cultivation process by UTEX 90 and CC 2656 were 113 mg L-1 d-1 and 74.95 mg L-1 d-1, respectively. The depigmented and defatted carbohydrate rich biomass was considered as raw material for bioethanol production. The bioethanol yield range was 90-94% of the theoretical yield using Saccharomyces cerevisiae INVSC-1 in a double jacket reactor. To improve the viability of the process, the spent media after ethanol fermentation was subsequently used for methane production using mixed microbial consortium. The energy recovery from the process was 40.39% and 39.7% for UTEX 90 and CC 2656, respectively when C. reinhardtii biomass was used as substrate for biofuel production. The present investigation concedes with the potentiality of algae as a favourable 3rd generation feedstock to address the existing challenges of clean energy production with concomitant CO2 sequestration.
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Affiliation(s)
- Sanjukta Banerjee
- Department of Biotechnology, Indian Institute of Technology, Kharagpur 721302, India
| | - Ayusmita Ray
- P K Sinha Centre for Bioenergy and Renewables, Indian Institute of Technology, Kharagpur 721302, India
| | - Debabrata Das
- Department of Biotechnology, Indian Institute of Technology, Kharagpur 721302, India.
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Water oxidation by photosystem II is the primary source of electrons for sustained H 2 photoproduction in nutrient-replete green algae. Proc Natl Acad Sci U S A 2020; 117:29629-29636. [PMID: 33168746 PMCID: PMC7703569 DOI: 10.1073/pnas.2009210117] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Photosynthetic H2 production in the green alga Chlamydomonas reinhardtii is catalyzed by O2-sensitive [FeFe]-hydrogenases, which accept electrons from photosynthetically reduced ferredoxin and reduce protons to H2. Since the process occurs downstream of photosystem I, the contribution of photosystem II (PSII) in H2 photoproduction has long been a subject of debate. Indeed, water oxidation by PSII results in O2 accumulation in chloroplasts, which inhibits H2 evolution. Therefore, clear evidence for direct water biophotolysis resulting in simultaneous H2 and O2 releases in algae has never been presented. This paper demonstrates that sustained H2 photoproduction in C. reinhardtii is directly linked to PSII-dependent water oxidation and brings insights into regulation of PSII activity and H2 production by CO2/HCO3– under microoxic conditions. The unicellular green alga Chlamydomonas reinhardtii is capable of photosynthetic H2 production. H2 evolution occurs under anaerobic conditions and is difficult to sustain due to 1) competition between [FeFe]-hydrogenase (H2ase), the key enzyme responsible for H2 metabolism in algae, and the Calvin–Benson–Bassham (CBB) cycle for photosynthetic reductants and 2) inactivation of H2ase by O2 coevolved in photosynthesis. Recently, we achieved sustainable H2 photoproduction by shifting algae from continuous illumination to a train of short (1 s) light pulses, interrupted by longer (9 s) dark periods. This illumination regime prevents activation of the CBB cycle and redirects photosynthetic electrons to H2ase. Employing membrane-inlet mass spectrometry and H218O, we now present clear evidence that efficient H2 photoproduction in pulse-illuminated algae depends primarily on direct water biophotolysis, where water oxidation at the donor side of photosystem II (PSII) provides electrons for the reduction of protons by H2ase downstream of photosystem I. This occurs exclusively in the absence of CO2 fixation, while with the activation of the CBB cycle by longer (8 s) light pulses the H2 photoproduction ceases and instead a slow overall H2 uptake is observed. We also demonstrate that the loss of PSII activity in DCMU-treated algae or in PSII-deficient mutant cells can be partly compensated for by the indirect (PSII-independent) H2 photoproduction pathway, but only for a short (<1 h) period. Thus, PSII activity is indispensable for a sustained process, where it is responsible for more than 92% of the final H2 yield.
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9
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Negi S, Perrine Z, Friedland N, Kumar A, Tokutsu R, Minagawa J, Berg H, Barry AN, Govindjee G, Sayre R. Light regulation of light-harvesting antenna size substantially enhances photosynthetic efficiency and biomass yield in green algae †. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:584-603. [PMID: 32180283 DOI: 10.1111/tpj.14751] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 02/06/2020] [Accepted: 03/09/2020] [Indexed: 05/25/2023]
Abstract
One of the major factors limiting biomass productivity in algae is the low thermodynamic efficiency of photosynthesis. The greatest thermodynamic inefficiencies in photosynthesis occur during the conversion of light into chemical energy. At full sunlight the light-harvesting antenna captures photons at a rate nearly 10 times faster than the rate-limiting step in photosynthetic electron transport. Excess captured energy is dissipated by non-productive pathways including the production of reactive oxygen species. Substantial improvements in photosynthetic efficiency have been achieved by reducing the optical cross-section of the light-harvesting antenna by selectively reducing chlorophyll b levels and peripheral light-harvesting complex subunits. Smaller light-harvesting antenna, however, may not exhibit optimal photosynthetic performance in low or fluctuating light environments. We describe a translational control system to dynamically adjust light-harvesting antenna sizes for enhanced photosynthetic performance. By expressing a chlorophyllide a oxygenase (CAO) gene having a 5' mRNA extension encoding a Nab1 translational repressor binding site in a CAO knockout line it was possible to continuously alter chlorophyll b levels and correspondingly light-harvesting antenna sizes by light-activated Nab1 repression of CAO expression as a function of growth light intensity. Significantly, algae having light-regulated antenna sizes had substantially higher photosynthetic rates and two-fold greater biomass productivity than the parental wild-type strains as well as near wild-type ability to carry out state transitions and non-photochemical quenching. These results have broad implications for enhanced algae and plant biomass productivity.
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Affiliation(s)
- Sangeeta Negi
- New Mexico Consortium and Los Alamos National Laboratory, Los Alamos, NM, 87544, USA
| | - Zoee Perrine
- Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA
| | | | - Anil Kumar
- Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA
| | - Ryutaro Tokutsu
- Division of Environmental Photobiology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, 444-8585, Japan
- Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), 38 Nishigonaka, Myodaiji, Okazaki, 444-8585, Japan
- CREST (Core Research for Evolutional Science and Technology), Japan Science and Technology Agency (JST), 38 Nishigonaka, Myodaiji, Okazaki, 444-8585, Japan
| | - Jun Minagawa
- Division of Environmental Photobiology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, 444-8585, Japan
- Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), 38 Nishigonaka, Myodaiji, Okazaki, 444-8585, Japan
- CREST (Core Research for Evolutional Science and Technology), Japan Science and Technology Agency (JST), 38 Nishigonaka, Myodaiji, Okazaki, 444-8585, Japan
| | - Howard Berg
- Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA
| | - Amanda N Barry
- Los Alamos National Laboratory, Los Alamos, NM, 87544, USA
| | - Govindjee Govindjee
- Department of Biochemistry, Department of Plant Biology, Center of Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
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Yaisamlee C, Sirikhachornkit A. Characterization of Chlamydomonas Very High Light-tolerant Mutants for Enhanced Lipid Production. J Oleo Sci 2020; 69:359-368. [PMID: 32249263 DOI: 10.5650/jos.ess19270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Biodiesel production from microalgae is still not commercially realized due to the high cost of production. High light-tolerance has been suggested as a desirable phenotype for efficient cultivation in large scale production systems under fluctuating outdoor conditions. Nevertheless, it has not been shown if algae with such a phenotype would have better efficiency for lipid production. To determine lipid productivity in high light-tolerant mutants, and to understand the pathways involved in high light-tolerant phenotype, two very high light-tolerant mutants of the green alga Chlamydomonas reinhardtii - CAL028_01_28 and CAL034_01_48 - were selected from eighteen high light-tolerant mutants from the CAL collection. Under high light intensity conditions, and the presence of reactive oxygen species, which are conditions constantly experienced by algae growing in open-pond environments, these strains exhibited higher photosynthetic efficiency and improved survival. The physiological characterization of these mutants revealed that the detoxification of ROS by carotenoids and antioxidant enzymes is crucial for their growth under high light conditions. Neither mutant was affected in terms of its ability to accumulate lipid under nitrogen-depleted condition. More importantly, lipid productivity under high light conditions increased twofold in these mutants compared to that of the wild-type. Taken together, very high light-tolerant mutants confer a high potential for biofuel production under outdoor conditions, and their improved ability to survive under oxidative stress is an important key for efficient growth under outdoor conditions.
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Affiliation(s)
- Chonlada Yaisamlee
- Microalgal Molecular Genetics and Functional Genomics Special Research Unit, Department of Genetics, Faculty of Science, Kasetsart University.,Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University
| | - Anchalee Sirikhachornkit
- Microalgal Molecular Genetics and Functional Genomics Special Research Unit, Department of Genetics, Faculty of Science, Kasetsart University.,Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University
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11
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Overexpression of malic enzyme isoform 2 in Chlamydomonas reinhardtii PTS42 increases lipid production. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.biteb.2019.100239] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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12
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Perin G, Bellan A, Bernardi A, Bezzo F, Morosinotto T. The potential of quantitative models to improve microalgae photosynthetic efficiency. PHYSIOLOGIA PLANTARUM 2019; 166:380-391. [PMID: 30578540 DOI: 10.1111/ppl.12915] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 12/14/2018] [Accepted: 12/18/2018] [Indexed: 06/09/2023]
Abstract
The massive increase in carbon dioxide concentration in the atmosphere driven by human activities is causing huge negative consequences and new sustainable sources of energy, food and materials are highly needed. Algae are unicellular photosynthetic microorganisms that can provide a highly strategic contribution to this challenge as alternative source of biomass to complement crops cultivation. Algae industrial cultures are commonly limited by light availability, and biomass accumulation is strongly dependent on their photon-to-biomass conversion efficiency. Investigation of algae photosynthetic metabolism is thus strategic for the generation of more efficient strains with higher productivity. Algae are cultivated at industrial scale in conditions highly different from the natural niches they adapted to and strains development efforts must fully consider the seminal influence on productivity of regulatory mechanism of photosynthesis as well as of cultivation parameters like cells concentration, light distribution in the culture, mixing, nutrients and carbon dioxide availability. In this review we will focus in particular on how mathematical models can account for the complex influence of all environmental parameters and can be exploited for development of improved algae strains.
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Affiliation(s)
- Giorgio Perin
- Department of Biology, University of Padova, Via Ugo Bassi 58/B 35131, Padova, Italy
| | - Alessandra Bellan
- Department of Biology, University of Padova, Via Ugo Bassi 58/B 35131, Padova, Italy
| | - Andrea Bernardi
- Department of Industrial Engineering, University of Padova, Via Marzolo 9 35131, Padova, Italy
- Centre for Process Systems Engineering, Department of Chemical Engineering, Imperial College London, SW7 2AZ, London, UK
| | - Fabrizio Bezzo
- Department of Industrial Engineering, University of Padova, Via Marzolo 9 35131, Padova, Italy
| | - Tomas Morosinotto
- Department of Biology, University of Padova, Via Ugo Bassi 58/B 35131, Padova, Italy
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13
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Physiological and Transcriptome Analysis of a Yellow-Green Leaf Mutant in Birch (Betula platyphylla × B. Pendula). FORESTS 2019. [DOI: 10.3390/f10020120] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Chlorophyll (Chl)-deficient mutants are ideal materials for the study of Chl biosynthesis, chloroplast development, and photosynthesis. Although the genes encoding key enzymes related to Chl biosynthesis have been well-characterized in herbaceous plants, rice (Oryza sativa L.), Arabidopsis (Arabidopsis thaliana), and maize (Zea mays L.), yellow-green leaf mutants have not yet been fully studied in tree species. In this work, we explored the molecular mechanism of the leaf color formation in a yellow-green leaf mutant (yl). We investigated the differentially expressed genes (DEGs) between yl and control plants (wild type birch (WT) and BpCCR1 overexpression line 11, (C11)) by transcriptome sequencing. Approximately 1163 genes (874 down-regulated and 289 up-regulated) and 930 genes (755 down-regulated and 175 up-regulated) were found to be differentially expressed in yl compared with WT and C11, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis for DEGs revealed that photosynthesis antenna proteins represent the most significant enriched pathway. The expressions of photosynthesis antenna proteins are crucial to the leaf color formation in yl. We also found that Chl accumulate, leaf anatomical structure, photosynthesis, and growth were affected in yl. Taken together, our results not only provide the difference of phenomenal, physiological, and gene expression characteristics in leaves between yl mutant and control plants, but also provide a new insight into the mutation underlying the chlorotic leaf phenotype in birch.
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Koh HG, Kang NK, Jeon S, Shin SE, Jeong BR, Chang YK. Heterologous synthesis of chlorophyll b in Nannochloropsis salina enhances growth and lipid production by increasing photosynthetic efficiency. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:122. [PMID: 31114631 PMCID: PMC6515666 DOI: 10.1186/s13068-019-1462-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 05/04/2019] [Indexed: 05/16/2023]
Abstract
BACKGROUND Chlorophylls play important roles in photosynthesis, and thus are critical for growth and related metabolic pathways in photosynthetic organisms. They are particularly important in microalgae, emerging as the next generation feedstock for biomass and biofuels. Nannochloropsis are industrial microalgae for these purposes, but are peculiar in that they lack accessory chlorophylls. In addition, the localization of heterologous proteins to the chloroplast of Nannochloropsis has not been fully studied, due to the secondary plastid surrounded by four membranes. This study addressed questions of correct localization and functional benefits of heterologous expression of chlorophyllide a oxygenase from Chlamydomonas (CrCAO) in Nannochloropsis. RESULTS We cloned CrCAO from Chlamydomonas, which catalyzes oxidation of Chla producing Chlb, and overexpressed it in N. salina to reveal effects of the heterologous Chlb for photosynthesis, growth, and lipid production. For correct localization of CrCAO into the secondary plastid in N. salina, we added the signal-recognition sequence and the transit peptide (cloned from an endogenous chloroplast-localized protein) to the N terminus of CrCAO. We obtained two transformants that expressed CrCAO and produced Chlb. They showed improved growth under medium light (90 μmol/m2/s) conditions, and their photosynthetic efficiency was increased compared to WT. They also showed increased expression of certain photosynthetic proteins, accompanied by an increased maximum electron-transfer rate up to 15.8% and quantum yields up to 17%, likely supporting the faster growth. This improved growth resulted in increased biomass production, and more importantly lipid productivity particularly with medium light. CONCLUSIONS We demonstrated beneficial effects of heterologous expression of CrCAO in Chlb-less organism N. salina, where the newly produced Chlb enhanced photosynthesis and growth. Accordingly, transformants showed improved production of biomass and lipids, important traits of microalgae from the industrial perspectives. Our transformants are the first Nannochloropsis cells that produced Chlb in the whole evolutionary path. We also succeeded in delivering a heterologous protein into the secondary plastid for the first time in Nannochloropsis. Taken together, our data showed that manipulation of photosynthetic pigments, including Chlb, can be employed in genetic improvements of microalgae for production of biofuels and other biomaterials.
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Affiliation(s)
- Hyun Gi Koh
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Nam Kyu Kang
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Present Address: Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Seungjib Jeon
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Sung-Eun Shin
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Present Address: LG Chem, 188 Munji-ro, Yuseong-gu, Daejeon, 34122 Republic of Korea
| | - Byeong-ryool Jeong
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Yong Keun Chang
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
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15
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Kirst H, Shen Y, Vamvaka E, Betterle N, Xu D, Warek U, Strickland JA, Melis A. Downregulation of the CpSRP43 gene expression confers a truncated light-harvesting antenna (TLA) and enhances biomass and leaf-to-stem ratio in Nicotiana tabacum canopies. PLANTA 2018; 248:139-154. [PMID: 29623472 DOI: 10.1007/s00425-018-2889-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/29/2018] [Indexed: 05/13/2023]
Abstract
MAIN CONCLUSION Downregulation in the expression of the signal recognition particle 43 (SRP43) gene in tobacco conferred a truncated photosynthetic light-harvesting antenna (TLA property), and resulted in plants with a greater leaf-to-stem ratio, improved photosynthetic productivity and canopy biomass accumulation under high-density cultivation conditions. Evolution of sizable arrays of light-harvesting antennae in all photosynthetic systems confers a survival advantage for the organism in the wild, where sunlight is often the growth-limiting factor. In crop monocultures, however, this property is strongly counterproductive, when growth takes place under direct and excess sunlight. The large arrays of light-harvesting antennae in crop plants cause the surface of the canopies to over-absorb solar irradiance, far in excess of what is needed to saturate photosynthesis and forcing them to engage in wasteful dissipation of the excess energy. Evidence in this work showed that downregulation by RNA-interference approaches of the Nicotiana tabacum signal recognition particle 43 (SRP43), a nuclear gene encoding a chloroplast-localized component of the photosynthetic light-harvesting assembly pathway, caused a decrease in the light-harvesting antenna size of the photosystems, a corresponding increase in the photosynthetic productivity of chlorophyll in the leaves, and improved tobacco plant canopy biomass accumulation under high-density cultivation conditions. Importantly, the resulting TLA transgenic plants had a substantially greater leaf-to-stem biomass ratio, compared to those of the wild type, grown under identical agronomic conditions. The results are discussed in terms of the potential benefit that could accrue to agriculture upon application of the TLA-technology to crop plants, entailing higher density planting with plants having a greater biomass and leaf-to-stem ratio, translating into greater crop yields per plant with canopies in a novel agronomic configuration.
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Affiliation(s)
- Henning Kirst
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720-3102, USA
| | - Yanxin Shen
- Biotechnology Division, Altria Client Services, Richmond, VA, 23219, USA
| | - Evangelia Vamvaka
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720-3102, USA
| | - Nico Betterle
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720-3102, USA
| | - Dongmei Xu
- Biotechnology Division, Altria Client Services, Richmond, VA, 23219, USA
| | - Ujwala Warek
- Biotechnology Division, Altria Client Services, Richmond, VA, 23219, USA
| | - James A Strickland
- Biotechnology Division, Altria Client Services, Richmond, VA, 23219, USA
| | - Anastasios Melis
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720-3102, USA.
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16
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Smith RT, Gilmour DJ. The influence of exogenous organic carbon assimilation and photoperiod on the carbon and lipid metabolism of Chlamydomonas reinhardtii. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.01.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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17
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Jeong J, Baek K, Yu J, Kirst H, Betterle N, Shin W, Bae S, Melis A, Jin E. Deletion of the chloroplast LTD protein impedes LHCI import and PSI-LHCI assembly in Chlamydomonas reinhardtii. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:1147-1158. [PMID: 29300952 PMCID: PMC6018721 DOI: 10.1093/jxb/erx457] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 12/12/2017] [Indexed: 05/26/2023]
Abstract
Nuclear-encoded light-harvesting chlorophyll- and carotenoid-binding proteins (LHCPs) are imported into the chloroplast and transported across the stroma to thylakoid membrane assembly sites by the chloroplast signal recognition particle (CpSRP) pathway. The LHCP translocation defect (LTD) protein is essential for the delivery of imported LHCPs to the CpSRP pathway in Arabidopsis. However, the function of the LTD protein in Chlamydomonas reinhardtii has not been investigated. Here, we generated a C. reinhardtii ltd (Crltd) knockout mutant by using CRISPR-Cas9, a new target-specific knockout technology. The Crltd1 mutant showed a low chlorophyll content per cell with an unusual increase in appressed thylakoid membranes and enlarged cytosolic vacuoles. Profiling of thylakoid membrane proteins in the Crltd1 mutant showed a more severe reduction in the levels of photosystem I (PSI) core proteins and absence of functional LHCI compared with those of photosystem II, resulting in a much smaller PSI pool size and diminished chlorophyll antenna size. The lack of CrLTD did not prevent photoautotrophic growth of the cells. These results are substantially different from those for Arabidopsis ltd null mutant, indicating LTD function in LHCP delivery and PSI assembly may not be as stringent in C. reinhardtii as it is in higher plants.
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Affiliation(s)
- Jooyeon Jeong
- Department of Life Science and Research Institute for Natural Sciences, Hanyang University, Seoul, Korea
| | - Kwangryul Baek
- Department of Life Science and Research Institute for Natural Sciences, Hanyang University, Seoul, Korea
| | - Jihyeon Yu
- School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Henning Kirst
- Department of Plant and Microbial Biology, University of California, Berkeley, California USA
| | - Nico Betterle
- Department of Plant and Microbial Biology, University of California, Berkeley, California USA
| | - Woongghi Shin
- Department of Biology, Chungnam National University, Daejeon, Korea
| | - Sangsu Bae
- Department of Chemistry, Hanyang University, Seoul, Korea
| | - Anastasios Melis
- Department of Plant and Microbial Biology, University of California, Berkeley, California USA
| | - EonSeon Jin
- Department of Life Science and Research Institute for Natural Sciences, Hanyang University, Seoul, Korea
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18
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Sharon-Gojman R, Leu S, Zarka A. Antenna size reduction and altered division cycles in self-cloned, marker-free genetically modified strains of Haematococcus pluvialis. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.09.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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19
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Sithtisarn S, Yokthongwattana K, Mahong B, Roytrakul S, Paemanee A, Phaonakrop N, Yokthongwattana C. Comparative proteomic analysis of Chlamydomonas reinhardtii control and a salinity-tolerant strain revealed a differential protein expression pattern. PLANTA 2017; 246:843-856. [PMID: 28688014 DOI: 10.1007/s00425-017-2734-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 07/01/2017] [Indexed: 06/07/2023]
Abstract
Proteins involved in membrane transport and trafficking, stress and defense, iron uptake and metabolism, as well as proteolytic enzymes, were remarkably up-regulated in the salinity-tolerant strain of Chlamydomonas reinhardtii. Excessive concentration of NaCl in the environment can cause adverse effects on plants and microalgae. Successful adaptation of plants to long-term salinity stress requires complex cellular adjustments at different levels from molecular, biochemical and physiological processes. In this study, we developed a salinity-tolerant strain (ST) of the model unicellular green alga, Chlamydomonas reinhardtii, capable of growing in medium containing 300 mM NaCl. Comparative proteomic analyses were performed to assess differential protein expression pattern between the ST and the control progenitor cells. Proteins involved in membrane transport and trafficking, stress and defense, iron uptake and metabolism, as well as protein degradation, were remarkably up-regulated in the ST cells, suggesting the importance of these processes in acclimation mechanisms to salinity stress. Moreover, 2-DE-based proteomic also revealed putative salinity-specific post-translational modifications (PTMs) on several important housekeeping proteins. Discussions were made regarding the roles of these differentially expressed proteins and the putative PTMs in cellular adaptation to long-term salinity stress.
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Affiliation(s)
- Sayamon Sithtisarn
- Department of Biochemistry, Faculty of Science, Kasetsart University, 50 Ngamwongwan Rd., Bangkok, 10900, Thailand
| | - Kittisak Yokthongwattana
- Department of Biochemistry and Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, 272 Rama 6 Rd., Bangkok, 10400, Thailand
| | - Bancha Mahong
- Department of Biochemistry and Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, 272 Rama 6 Rd., Bangkok, 10400, Thailand
| | - Sittiruk Roytrakul
- Genome Institute, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Rd., Pathumthani, 12120, Thailand
| | - Atchara Paemanee
- Genome Institute, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Rd., Pathumthani, 12120, Thailand
| | - Narumon Phaonakrop
- Genome Institute, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Rd., Pathumthani, 12120, Thailand
| | - Chotika Yokthongwattana
- Department of Biochemistry, Faculty of Science, Kasetsart University, 50 Ngamwongwan Rd., Bangkok, 10900, Thailand.
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20
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Banerjee A, Banerjee C, Negi S, Chang JS, Shukla P. Improvements in algal lipid production: a systems biology and gene editing approach. Crit Rev Biotechnol 2017; 38:369-385. [DOI: 10.1080/07388551.2017.1356803] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Avik Banerjee
- Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, India
| | - Chiranjib Banerjee
- Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, India
| | | | - Jo-Shu Chang
- Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Pratyoosh Shukla
- Department of Microbiology, Enzyme Technology and Protein Bioinformatics Laboratory, Maharshi Dayanand University, Rohtak, India
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21
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Kirst H, Gabilly ST, Niyogi KK, Lemaux PG, Melis A. Photosynthetic antenna engineering to improve crop yields. PLANTA 2017; 245:1009-1020. [PMID: 28188423 DOI: 10.1007/s00425-017-2659-y] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 02/03/2017] [Indexed: 05/05/2023]
Abstract
MAIN CONCLUSION Evidence shows that decreasing the light-harvesting antenna size of the photosystems in tobacco helps to increase the photosynthetic productivity and plant canopy biomass accumulation under high-density cultivation conditions. Decreasing, or truncating, the chlorophyll antenna size of the photosystems can theoretically improve photosynthetic solar energy conversion efficiency and productivity in mass cultures of algae or plants by up to threefold. A Truncated Light-harvesting chlorophyll Antenna size (TLA), in all classes of photosynthetic organisms, would help to alleviate excess absorption of sunlight and the ensuing wasteful non-photochemical dissipation of excitation energy. Thus, solar-to-biomass energy conversion efficiency and photosynthetic productivity in high-density cultures can be increased. Applicability of the TLA concept was previously shown in green microalgae and cyanobacteria, but it has not yet been demonstrated in crop plants. In this work, the TLA concept was applied in high-density tobacco canopies. The work showed a 25% improvement in stem and leaf biomass accumulation for the TLA tobacco canopies over that measured with their wild-type counterparts grown under the same ambient conditions. Distinct canopy appearance differences are described between the TLA and wild type tobacco plants. Findings are discussed in terms of concept application to crop plants, leading to significant improvements in agronomy, agricultural productivity, and application of photosynthesis for the generation of commodity products in crop leaves.
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Affiliation(s)
- Henning Kirst
- Department of Plant and Microbial Biology, University of California, 111 Koshland Hall, MC-3102, Berkeley, CA, 94720-3102, USA
| | - Stéphane T Gabilly
- Department of Plant and Microbial Biology, University of California, 111 Koshland Hall, MC-3102, Berkeley, CA, 94720-3102, USA
| | - Krishna K Niyogi
- Department of Plant and Microbial Biology, University of California, 111 Koshland Hall, MC-3102, Berkeley, CA, 94720-3102, USA
- Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720-3102, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Peggy G Lemaux
- Department of Plant and Microbial Biology, University of California, 111 Koshland Hall, MC-3102, Berkeley, CA, 94720-3102, USA
| | - Anastasios Melis
- Department of Plant and Microbial Biology, University of California, 111 Koshland Hall, MC-3102, Berkeley, CA, 94720-3102, USA.
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22
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Bujaldon S, Kodama N, Rappaport F, Subramanyam R, de Vitry C, Takahashi Y, Wollman FA. Functional Accumulation of Antenna Proteins in Chlorophyll b-Less Mutants of Chlamydomonas reinhardtii. MOLECULAR PLANT 2017; 10:115-130. [PMID: 27742488 DOI: 10.1016/j.molp.2016.10.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 09/01/2016] [Accepted: 10/04/2016] [Indexed: 05/29/2023]
Abstract
The green alga Chlamydomonas reinhardtii contains several light-harvesting chlorophyll a/b complexes (LHC): four major LHCIIs, two minor LHCIIs, and nine LHCIs. We characterized three chlorophyll b-less mutants to assess the effect of chlorophyll b deficiency on the function, assembly, and stability of these chlorophyll a/b binding proteins. We identified point mutations in two mutants that inactivate the CAO gene responsible for chlorophyll a to chlorophyll b conversion. All LHCIIs accumulated to wild-type levels in a CAO mutant but their light-harvesting function for photosystem II was impaired. In contrast, most LHCIs accumulated to wild-type levels in the mutant and their light-harvesting capability for photosystem I remained unaltered. Unexpectedly, LHCI accumulation and the photosystem I functional antenna size increased in the mutant compared with in the wild type when grown in dim light. When the CAO mutation was placed in a yellow-in-the-dark background (yid-BF3), in which chlorophyll a synthesis remains limited in dim light, accumulation of the major LHCIIs and of most LHCIs was markedly reduced, indicating that sustained synthesis of chlorophyll a is required to preserve the proteolytic resistance of antenna proteins. Indeed, after crossing yid-BF3 with a mutant defective for the thylakoid FtsH protease activity, yid-BF3-ftsh1 restored wild-type levels of LHCI, which defines LHCI as a new substrate for the FtsH protease.
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Affiliation(s)
- Sandrine Bujaldon
- Institut de Biologie Physico-Chimique, UMR7141 CNRS-UPMC, Paris 75005, France
| | - Natsumi Kodama
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan; JST-CREST, Okayama University, Okayama 700-8530, Japan
| | - Fabrice Rappaport
- Institut de Biologie Physico-Chimique, UMR7141 CNRS-UPMC, Paris 75005, France
| | - Rajagopal Subramanyam
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Catherine de Vitry
- Institut de Biologie Physico-Chimique, UMR7141 CNRS-UPMC, Paris 75005, France
| | - Yuichiro Takahashi
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan; JST-CREST, Okayama University, Okayama 700-8530, Japan.
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23
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Jia T, Ito H, Tanaka A. Simultaneous regulation of antenna size and photosystem I/II stoichiometry in Arabidopsis thaliana. PLANTA 2016; 244:1041-1053. [PMID: 27394155 DOI: 10.1007/s00425-016-2568-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 07/06/2016] [Indexed: 05/10/2023]
Abstract
The photosystem I/II ratio increased when antenna size was enlarged by transient induction of CAO in chlorophyll b -less mutants, thus indicating simultaneous regulation of antenna size and photosystem I/II stoichiometry. Regulation of antenna size and photosystem I/II stoichiometry is an indispensable strategy for plants to acclimate to changes to light environments. When plants grown in high-light conditions are transferred to low-light conditions, the peripheral antennae of photosystems are enlarged. A change in the photosystem I/II ratio is also observed under the same light conditions. However, our knowledge of the correlation between antenna size modulation and variation in photosystem I/II stoichiometry remains limited. In this study, chlorophyll a oxygenase was transiently induced in Arabidopsis thaliana chlorophyll b-less mutants, ch1-1, to alter the antenna size without changing environmental conditions. In addition to the accumulation of chlorophyll b, the levels of the peripheral antenna complexes of both photosystems gradually increased, and these were assembled to the core antenna of both photosystems. However, the antenna size of photosystem II was greater than that of photosystem I. Immunoblot analysis of core antenna proteins showed that the number of photosystem I increased, but not that of photosystem II, resulting in an increase in the photosystem I/II ratio. These results clearly indicate that antenna size adjustment was coupled with changes in photosystem I/II stoichiometry. Based on these results, the physiological importance of simultaneous regulation of antenna size and photosystem I/II stoichiometry is discussed in relation to acclimation to light conditions.
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Affiliation(s)
- Ting Jia
- Institute of Low Temperature Science, Hokkaido University, N19 W8, Kita-ku, Sapporo, 060-0819, Japan
| | - Hisashi Ito
- Institute of Low Temperature Science, Hokkaido University, N19 W8, Kita-ku, Sapporo, 060-0819, Japan.
- CREST, Japan Science and Technology Agency, N19 W8, Kita-ku, Sapporo, 060-0819, Japan.
| | - Ayumi Tanaka
- Institute of Low Temperature Science, Hokkaido University, N19 W8, Kita-ku, Sapporo, 060-0819, Japan
- CREST, Japan Science and Technology Agency, N19 W8, Kita-ku, Sapporo, 060-0819, Japan
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24
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Shin SE, Lim JM, Koh HG, Kim EK, Kang NK, Jeon S, Kwon S, Shin WS, Lee B, Hwangbo K, Kim J, Ye SH, Yun JY, Seo H, Oh HM, Kim KJ, Kim JS, Jeong WJ, Chang YK, Jeong BR. CRISPR/Cas9-induced knockout and knock-in mutations in Chlamydomonas reinhardtii. Sci Rep 2016; 6:27810. [PMID: 27291619 PMCID: PMC4904240 DOI: 10.1038/srep27810] [Citation(s) in RCA: 200] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 05/25/2016] [Indexed: 01/20/2023] Open
Abstract
Genome editing is crucial for genetic engineering of organisms for improved traits, particularly in microalgae due to the urgent necessity for the next generation biofuel production. The most advanced CRISPR/Cas9 system is simple, efficient and accurate in some organisms; however, it has proven extremely difficult in microalgae including the model alga Chlamydomonas. We solved this problem by delivering Cas9 ribonucleoproteins (RNPs) comprising the Cas9 protein and sgRNAs to avoid cytotoxicity and off-targeting associated with vector-driven expression of Cas9. We obtained CRISPR/Cas9-induced mutations at three loci including MAA7, CpSRP43 and ChlM, and targeted mutagenic efficiency was improved up to 100 fold compared to the first report of transgenic Cas9-induced mutagenesis. Interestingly, we found that unrelated vectors used for the selection purpose were predominantly integrated at the Cas9 cut site, indicative of NHEJ-mediated knock-in events. As expected with Cas9 RNPs, no off-targeting was found in one of the mutagenic screens. In conclusion, we improved the knockout efficiency by using Cas9 RNPs, which opens great opportunities not only for biological research but also industrial applications in Chlamydomonas and other microalgae. Findings of the NHEJ-mediated knock-in events will allow applications of the CRISPR/Cas9 system in microalgae, including "safe harboring" techniques shown in other organisms.
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Affiliation(s)
- Sung-Eun Shin
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Jong-Min Lim
- Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
| | - Hyun Gi Koh
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Eun Kyung Kim
- Advanced Biomass R&D Center (ABC), KAIST, Daejeon 34141, Republic of Korea
| | - Nam Kyu Kang
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Seungjib Jeon
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Sohee Kwon
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Won-Sub Shin
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Bongsoo Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Kwon Hwangbo
- Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
- Department of Biological Science, Chungnam National University (CNU), Daejeon 34134, Republic of Korea
| | - Jungeun Kim
- Center for Genome Engineering, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Chemistry, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - Sung Hyeok Ye
- Center for Genome Engineering, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Basic science, IBS school, Korea University of Science and Technology (UST), Seoul 08826, Republic of Korea
| | - Jae-Young Yun
- Center for Genome Engineering, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
| | - Hogyun Seo
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University (KNU), Daegu 41566, Republic of Korea
| | - Hee-Mock Oh
- Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
| | - Kyung-Jin Kim
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University (KNU), Daegu 41566, Republic of Korea
| | - Jin-Soo Kim
- Center for Genome Engineering, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Chemistry, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - Won-Joong Jeong
- Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
- Advanced Biomass R&D Center (ABC), KAIST, Daejeon 34141, Republic of Korea
| | - Byeong-ryool Jeong
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
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Wang JT, Hsu CM, Kuo CY, Meng PJ, Kao SJ, Chen CA. Physiological outperformance at the morphologically-transformed edge of the cyanobacteriosponge Terpios hoshinota (Suberitidae: Hadromerida) when confronting opponent corals. PLoS One 2015; 10:e0131509. [PMID: 26110525 PMCID: PMC4481517 DOI: 10.1371/journal.pone.0131509] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 06/03/2015] [Indexed: 11/18/2022] Open
Abstract
Terpios hoshinota, an encrusting cyanosponge, is known as a strong substrate competitor of reef-building corals that kills encountered coral by overgrowth. Terpios outbreaks cause significant declines in living coral cover in Indo-Pacific coral reefs, with the damage usually lasting for decades. Recent studies show that there are morphological transformations at a sponge's growth front when confronting corals. Whether these morphological transformations at coral contacts are involved with physiological outperformance (e.g., higher metabolic activity or nutritional status) over other portions of Terpios remains equivocal. In this study, we compared the indicators of photosynthetic capability and nitrogen status of a sponge-cyanobacteria association at proximal, middle, and distal portions of opponent corals. Terpios tissues in contact with corals displayed significant increases in photosynthetic oxygen production (ca. 61%), the δ13C value (ca. 4%), free proteinogenic amino acid content (ca. 85%), and Gln/Glu ratio (ca. 115%) compared to middle and distal parts of the sponge. In contrast, the maximum quantum yield (Fv/Fm), which is the indicator usually used to represent the integrity of photosystem II, of cyanobacteria photosynthesis was low (0.256~0.319) and showed an inverse trend of higher values in the distal portion of the sponge that might be due to high and variable levels of cyanobacterial phycocyanin. The inconsistent results between photosynthetic oxygen production and Fv/Fm values indicated that maximum quantum yields might not be a suitable indicator to represent the photosynthetic function of the Terpios-cyanobacteria association. Our data conclusively suggest that Terpios hoshinota competes with opponent corals not only by the morphological transformation of the sponge-cyanobacteria association but also by physiological outperformance in accumulating resources for the battle.
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Affiliation(s)
- Jih-Terng Wang
- Graduate Institute of Biotechnology, Tajen University, Pingtung, Taiwan
| | - Chia-Min Hsu
- Institute of Oceanography, National Taiwan University, Taipei, Taiwan
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Chao-Yang Kuo
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
- ARC Centre for Coral Reef Studies, James Cook University, Townsville, Australia
| | - Pei-Jie Meng
- National Museum of Marine Biology and Aquarium, Checheng, Pingtung, Taiwan
- Institute of Marine Biodiversity and Evolution, National Dong Hwa University Checheng, Pingtung, Taiwan
| | - Shuh-Ji Kao
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - Chaolun Allen Chen
- Institute of Oceanography, National Taiwan University, Taipei, Taiwan
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
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26
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Biogenesis of light harvesting proteins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:861-71. [PMID: 25687893 DOI: 10.1016/j.bbabio.2015.02.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 02/04/2015] [Accepted: 02/07/2015] [Indexed: 11/20/2022]
Abstract
The LHC family includes nuclear-encoded, integral thylakoid membrane proteins, most of which coordinate chlorophyll and xanthophyll chromophores. By assembling with the core complexes of both photosystems, LHCs form a flexible peripheral moiety for enhancing light-harvesting cross-section, regulating its efficiency and providing protection against photo-oxidative stress. Upon its first appearance, LHC proteins underwent evolutionary diversification into a large protein family with a complex genetic redundancy. Such differentiation appears as a crucial event in the adaptation of photosynthetic organisms to changing environmental conditions and land colonization. The structure of photosystems, including nuclear- and chloroplast-encoded subunits, presented the cell with a number of challenges for the control of the light harvesting function. Indeed, LHC-encoding messages are translated in the cytosol, and pre-proteins imported into the chloroplast, processed to their mature size and targeted to the thylakoids where are assembled with chromophores. Thus, a tight coordination between nuclear and plastid gene expression, in response to environmental stimuli, is required to adjust LHC composition during photoacclimation. In recent years, remarkable progress has been achieved in elucidating structure, function and regulatory pathways involving LHCs; however, a number of molecular details still await elucidation. In this review, we will provide an overview on the current knowledge on LHC biogenesis, ranging from organization of pigment-protein complexes to the modulation of gene expression, import and targeting to the photosynthetic membranes, and regulation of LHC assembly and turnover. Genes controlling these events are potential candidate for biotechnological applications aimed at optimizing light use efficiency of photosynthetic organisms. This article is part of a Special Issue entitled: Chloroplast biogenesis.
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Perin G, Bellan A, Segalla A, Meneghesso A, Alboresi A, Morosinotto T. Generation of random mutants to improve light-use efficiency of Nannochloropsis gaditana cultures for biofuel production. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:161. [PMID: 26413160 PMCID: PMC4583171 DOI: 10.1186/s13068-015-0337-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 09/09/2015] [Indexed: 05/02/2023]
Abstract
BACKGROUND The productivity of an algal culture depends on how efficiently it converts sunlight into biomass and lipids. Wild-type algae in their natural environment evolved to compete for light energy and maximize individual cell growth; however, in a photobioreactor, global productivity should be maximized. Improving light use efficiency is one of the primary aims of algae biotechnological research, and genetic engineering can play a major role in attaining this goal. RESULTS In this work, we generated a collection of Nannochloropsis gaditana mutant strains and screened them for alterations in the photosynthetic apparatus. The selected mutant strains exhibited diverse phenotypes, some of which are potentially beneficial under the specific artificial conditions of a photobioreactor. Particular attention was given to strains showing reduced cellular pigment contents, and further characterization revealed that some of the selected strains exhibited improved photosynthetic activity; in at least one case, this trait corresponded to improved biomass productivity in lab-scale cultures. CONCLUSIONS This work demonstrates that genetic modification of N. gaditana has the potential to generate strains with improved biomass productivity when cultivated under the artificial conditions of a photobioreactor.
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Affiliation(s)
- Giorgio Perin
- />Dipartimento di Biologia, Università di Padova, Via U. Bassi 58/B, 35121 Padua, Italy
| | - Alessandra Bellan
- />Dipartimento di Biologia, Università di Padova, Via U. Bassi 58/B, 35121 Padua, Italy
- />Centro studi di economia e tecnica dell’energia Giorgio Levi Cases, Università di Padova, Padua, Italy
| | - Anna Segalla
- />Dipartimento di Biologia, Università di Padova, Via U. Bassi 58/B, 35121 Padua, Italy
| | - Andrea Meneghesso
- />Dipartimento di Biologia, Università di Padova, Via U. Bassi 58/B, 35121 Padua, Italy
| | - Alessandro Alboresi
- />Dipartimento di Biologia, Università di Padova, Via U. Bassi 58/B, 35121 Padua, Italy
| | - Tomas Morosinotto
- />Dipartimento di Biologia, Università di Padova, Via U. Bassi 58/B, 35121 Padua, Italy
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Gérin S, Mathy G, Franck F. Modeling the dependence of respiration and photosynthesis upon light, acetate, carbon dioxide, nitrate and ammonium in Chlamydomonas reinhardtii using design of experiments and multiple regression. BMC SYSTEMS BIOLOGY 2014; 8:96. [PMID: 25123231 PMCID: PMC4236732 DOI: 10.1186/s12918-014-0096-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 08/04/2014] [Indexed: 11/10/2022]
Abstract
BACKGROUND In photosynthetic organisms, the influence of light, carbon and inorganic nitrogen sources on the cellular bioenergetics has extensively been studied independently, but little information is available on the cumulative effects of these factors. Here, sequential statistical analyses based on design of experiments (DOE) coupled to standard least squares multiple regression have been undertaken to model the dependence of respiratory and photosynthetic responses (assessed by oxymetric and chlorophyll fluorescence measurements) upon the concomitant modulation of light intensity as well as acetate, CO₂, nitrate and ammonium concentrations in the culture medium of Chlamydomonas reinhardtii. The main goals of these analyses were to explain response variability (i.e. bioenergetic plasticity) and to characterize quantitatively the influence of the major explanatory factor(s). RESULTS For each response, 2 successive rounds of multiple regression coupled to one-way ANOVA F-tests have been undertaken to select the major explanatory factor(s) (1st-round) and mathematically simulate their influence (2nd-round). These analyses reveal that a maximal number of 3 environmental factors over 5 is sufficient to explain most of the response variability, and interestingly highlight quadratic effects and second-order interactions in some cases. In parallel, the predictive ability of the 2nd-round models has also been investigated by k-fold cross-validation and experimental validation tests on new random combinations of factors. These validation procedures tend to indicate that the 2nd-round models can also be used to predict the responses with an inherent deviation quantified by the analytical error of the models. CONCLUSIONS Altogether, the results of the 2 rounds of modeling provide an overview of the bioenergetic adaptations of C. reinhardtii to changing environmental conditions and point out promising tracks for future in-depth investigations of the molecular mechanisms underlying the present observations.
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Affiliation(s)
| | | | - Fabrice Franck
- Laboratory of Bioenergetics, Department of Life Sciences, Faculty of Sciences, University of Liege, Boulevard du Rectorat 27, Liege, 4000, Belgium.
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29
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Madireddi SK, Nama S, Devadasu ER, Subramanyam R. Photosynthetic membrane organization and role of state transition in cyt, cpII, stt7 and npq mutants of Chlamydomonas reinhardtii. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2014; 137:77-83. [DOI: 10.1016/j.jphotobiol.2014.03.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 03/13/2014] [Accepted: 03/31/2014] [Indexed: 11/29/2022]
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30
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Alterations in Structural Organization Affect the Functional Ability of Photosynthetic Apparatus. ACTA ACUST UNITED AC 2014. [DOI: 10.1201/b16675-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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31
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Drop B, Webber-Birungi M, Yadav SK, Filipowicz-Szymanska A, Fusetti F, Boekema EJ, Croce R. Light-harvesting complex II (LHCII) and its supramolecular organization in Chlamydomonas reinhardtii. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:63-72. [DOI: 10.1016/j.bbabio.2013.07.012] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 07/23/2013] [Accepted: 07/30/2013] [Indexed: 11/25/2022]
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32
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Shen Y. Carbon dioxide bio-fixation and wastewater treatment via algae photochemical synthesis for biofuels production. RSC Adv 2014. [DOI: 10.1039/c4ra06441k] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Utilizing the energy, nutrients and CO2held within residual waste materials to provide all necessary inputs except for sunlight, the cultivation of algae becomes a closed-loop engineered ecosystem. Developing this green biotechnology is a tangible step towards a waste-free sustainable society.
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Affiliation(s)
- Yafei Shen
- Department of Environmental Science and Technology
- Interdisciplinary Graduate School of Science and Engineering
- Tokyo Institute of Technology
- Yokohama, Japan
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33
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Photobiological hydrogen production: Bioenergetics and challenges for its practical application. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2013. [DOI: 10.1016/j.jphotochemrev.2013.05.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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35
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Mitra M, Kirst H, Dewez D, Melis A. Modulation of the light-harvesting chlorophyll antenna size in Chlamydomonas reinhardtii by TLA1 gene over-expression and RNA interference. Philos Trans R Soc Lond B Biol Sci 2012; 367:3430-43. [PMID: 23148270 PMCID: PMC3497077 DOI: 10.1098/rstb.2012.0229] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Truncated light-harvesting antenna 1 (TLA1) is a nuclear gene proposed to regulate the chlorophyll (Chl) antenna size in Chlamydomonas reinhardtii. The Chl antenna size of the photosystems and the chloroplast ultrastructure were manipulated upon TLA1 gene over-expression and RNAi downregulation. The TLA1 over-expressing lines possessed a larger chlorophyll antenna size for both photosystems and contained greater levels of Chl b per cell relative to the wild type. Conversely, TLA1 RNAi transformants had a smaller Chl antenna size for both photosystems and lower levels of Chl b per cell. Western blot analyses of the TLA1 over-expressing and RNAi transformants showed that modulation of TLA1 gene expression was paralleled by modulation in the expression of light-harvesting protein, reaction centre D1 and D2, and VIPP1 genes. Transmission electron microscopy showed that modulation of TLA1 gene expression impacts the organization of thylakoid membranes in the chloroplast. Over-expressing lines showed well-defined grana, whereas RNAi transformants possessed loosely held together and more stroma-exposed thylakoids. Cell fractionation suggested localization of the TLA1 protein in the inner chloroplast envelope and potentially in association with nascent thylakoid membranes, indicating a role in Chl antenna assembly and thylakoid membrane biogenesis. The results provide a mechanistic understanding of the Chl antenna size regulation by the TLA1 gene.
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Affiliation(s)
- Mautusi Mitra
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
- Department of Biology, University of West Georgia, Carrollton, GA 30118, USA
| | - Henning Kirst
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - David Dewez
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Anastasios Melis
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
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36
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Formighieri C, Franck F, Bassi R. Regulation of the pigment optical density of an algal cell: Filling the gap between photosynthetic productivity in the laboratory and in mass culture. J Biotechnol 2012; 162:115-23. [DOI: 10.1016/j.jbiotec.2012.02.021] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 02/27/2012] [Accepted: 02/29/2012] [Indexed: 11/26/2022]
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37
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38
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Liu CH, Li XY, Zhang JH, Lin DZ, Dong YJ. [Characteristics and molecular mapping of a novel chlorophyll-deficient yellow-leaf mutant in rice]. YI CHUAN = HEREDITAS 2012; 34:223-9. [PMID: 22382064 DOI: 10.3724/sp.j.1005.2012.00223] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A yellow-leaf mutant (yl11) with chlorophyll-deficient in rice (Oryza sativa L.) was selected from the progeny of a japonica rice variety "Jiahua 1" treated with 60Co γ-radiation. In comparison with the wild-type parent, "Jiahua 1", the mutant had yellow-leaves at whole growth stages and displayed significantly decreased in chlorophyll content and net photosynthetic rate. Underdeveloped chloroplast and alterations of the major agronomic traits, such as plant-heights, were also observed in the mutant. Genetic analysis confirmed that the yellow-leaf mutant trait was controlled by a single recessive nuclear gene (yl11). Using SSR and In/Del molecular markers and 920 F2 and F3 plants from the cross of yl11 with the indica variety Peiai 64S, the yl11 was mapped between the molecular markers MM2199 and InDel21039 with a physical distance of 110 kb on the long arm of chromosome 11, in which no known functional genes for chlorophyll synthesis or chloroplast development in rice has been found. These findings will provide a foundation for the cloning and functional analysis of this gene in the future.
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39
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Ferrante P, Ballottari M, Bonente G, Giuliano G, Bassi R. LHCBM1 and LHCBM2/7 polypeptides, components of major LHCII complex, have distinct functional roles in photosynthetic antenna system of Chlamydomonas reinhardtii. J Biol Chem 2012; 287:16276-88. [PMID: 22431727 DOI: 10.1074/jbc.m111.316729] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The photosystem II antenna of Chlamydomonas reinhardtii is composed of monomeric and trimeric complexes, the latter encoded by LHCBM genes. We employed artificial microRNA technology to specifically silence the LHCBM2 and LHCBM7 genes, encoding identical mature polypeptides, and the LHCBM1 gene. As a control, we studied the npq5 mutant, deficient in the LHCBM1 protein. The organization of LHCII complexes, functional antenna size, capacity for photoprotection, thermal energy dissipation and state transitions, and resistance to reactive oxygen species was studied in the various genotypes. Silencing of the LHCBM2/7 genes resulted in a decrease of an LHCII protein with an apparent molecular mass of 22 kDa, whereas silencing/lack of LHCBM1 caused the decrease/disappearance of a 23-kDa protein. A decrease in the abundance of trimeric LHCII complexes and in functional antenna size was observed in both LHCBM2/7 and LHCBM1 knockouts. In agreement with previous data, depletion of LHCBM1 decreased the capacity for excess energy dissipation but not the ability to perform state transitions. The opposite was true for LHCBM2/7, implying that this polypeptide has a different functional role from LHCBM1. The abundance of LHCBM1 and LHCBM2/7 is in both cases correlated with resistance to superoxide anion, whereas only LHCBM1 is also involved in singlet oxygen scavenging. These results suggest that different LHCBM components have well defined, non-redundant functions despite their high homology, implying that engineering of LHCBM proteins can be an effective strategy for manipulating the light harvesting system of Chlamydomonas reinhardtii.
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Affiliation(s)
- Paola Ferrante
- ENEA (Italian National Agency for New technologies, Energy, and Sustainable Development), Casaccia Research Center, Via Anguillarese 301, 00123 Rome, Italy
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40
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Mahong B, Roytrakul S, Phaonaklop N, Wongratana J, Yokthongwattana K. Proteomic analysis of a model unicellular green alga, Chlamydomonas reinhardtii, during short-term exposure to irradiance stress reveals significant down regulation of several heat-shock proteins. PLANTA 2012; 235:499-511. [PMID: 21960164 DOI: 10.1007/s00425-011-1521-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Accepted: 09/14/2011] [Indexed: 05/31/2023]
Abstract
Oxygenic photosynthetic organisms often suffer from excessive irradiance, which cause harmful effects to the chloroplast proteins and lipids. Photoprotection and the photosystem II repair processes are the mechanisms that plants deploy to counteract the drastic effects from irradiance stress. Although the protective and repair mechanisms seemed to be similar in most plants, many species do confer different level of tolerance toward high light. Such diversity may originate from differences at the molecular level, i.e., perception of the light stress, signal transduction and expression of stress responsive genes. Comprehensive analysis of overall changes in the total pool of proteins in an organism can be performed using a proteomic approach. In this study, we employed 2-DE/LC-MS/MS-based comparative proteomic approach to analyze total proteins of the light sensitive model unicellular green alga Chlamydomonas reinhardtii in response to excessive irradiance. Results showed that among all the differentially expressed proteins, several heat-shock proteins and molecular chaperones were surprisingly down-regulated after 3-6 h of high light exposure. Discussions were made on the possible involvement of such down regulation and the light sensitive nature of this model alga.
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Affiliation(s)
- Bancha Mahong
- Department of Biochemistry and Center for Excellence in Protein Structure and Function, Mahidol University, Bangkok 10400, Thailand
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41
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Kirst H, García-Cerdán JG, Zurbriggen A, Melis A. Assembly of the light-harvesting chlorophyll antenna in the green alga Chlamydomonas reinhardtii requires expression of the TLA2-CpFTSY gene. PLANT PHYSIOLOGY 2012; 158:930-45. [PMID: 22114096 PMCID: PMC3271779 DOI: 10.1104/pp.111.189910] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Accepted: 11/22/2011] [Indexed: 05/18/2023]
Abstract
The truncated light-harvesting antenna2 (tla2) mutant of Chlamydomonas reinhardtii showed a lighter-green phenotype, had a lower chlorophyll (Chl) per-cell content, and higher Chl a/b ratio than corresponding wild-type strains. Physiological analyses revealed a higher intensity for the saturation of photosynthesis and greater P(max) values in the tla2 mutant than in the wild type. Biochemical analyses showed that the tla2 strain was deficient in the Chl a-b light-harvesting complex, and had a Chl antenna size of the photosystems that was only about 65% of that in the wild type. Molecular and genetic analyses showed a single plasmid insertion in the tla2 strain, causing a chromosomal DNA rearrangement and deletion/disruption of five nuclear genes. The TLA2 gene, causing the tla2 phenotype, was cloned by mapping the insertion site and upon complementation with each of the genes that were deleted. Successful complementation was achieved with the C. reinhardtii TLA2-CpFTSY gene, whose occurrence and function in green microalgae has not hitherto been investigated. Functional analysis showed that the nuclear-encoded and chloroplast-localized CrCpFTSY protein specifically operates in the assembly of the peripheral components of the Chl a-b light-harvesting antenna. In higher plants, a cpftsy null mutation inhibits assembly of both the light-harvesting complex and photosystem complexes, thus resulting in a seedling-lethal phenotype. The work shows that cpftsy deletion in green algae, but not in higher plants, can be employed to generate tla mutants. The latter exhibit improved solar energy conversion efficiency and photosynthetic productivity under mass culture and bright sunlight conditions.
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42
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Bonente G, Pippa S, Castellano S, Bassi R, Ballottari M. Acclimation of Chlamydomonas reinhardtii to different growth irradiances. J Biol Chem 2011; 287:5833-47. [PMID: 22205699 DOI: 10.1074/jbc.m111.304279] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We report on the changes the photosynthetic apparatus of Chlamydomonas reinhardtii undergoes upon acclimation to different light intensity. When grown in high light, cells had a faster growth rate and higher biomass production compared with low and control light conditions. However, cells acclimated to low light intensity are indeed able to produce more biomass per photon available as compared with high light-acclimated cells, which dissipate as heat a large part of light absorbed, thus reducing their photosynthetic efficiency. This dissipative state is strictly dependent on the accumulation of LhcSR3, a protein related to light-harvesting complexes, responsible for nonphotochemical quenching in microalgae. Other changes induced in the composition of the photosynthetic apparatus upon high light acclimation consist of an increase of carotenoid content on a chlorophyll basis, particularly zeaxanthin, and a major down-regulation of light absorption capacity by decreasing the chlorophyll content per cell. Surprisingly, the antenna size of both photosystem I and II is not modulated by acclimation; rather, the regulation affects the PSI/PSII ratio. Major effects of the acclimation to low light consist of increased activity of state 1 and 2 transitions and increased contributions of cyclic electron flow.
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Affiliation(s)
- Giulia Bonente
- Dipartimento di Biotecnologie, Università di Verona, Ca'Vignal 1, Strada le Grazie 15, I-37134 Verona, Italy
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43
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Larkum AWD, Ross IL, Kruse O, Hankamer B. Selection, breeding and engineering of microalgae for bioenergy and biofuel production. Trends Biotechnol 2011; 30:198-205. [PMID: 22178650 DOI: 10.1016/j.tibtech.2011.11.003] [Citation(s) in RCA: 145] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 11/07/2011] [Accepted: 11/07/2011] [Indexed: 01/08/2023]
Abstract
Microalgal production technologies are seen as increasingly attractive for bioenergy production to improve fuel security and reduce CO(2) emissions. Photosynthetically derived fuels are a renewable, potentially carbon-neutral and scalable alternative reserve. Microalgae have particular promise because they can be produced on non-arable land and utilize saline and wastewater streams. Furthermore, emerging microalgal technologies can be used to produce a range of products such as biofuels, protein-rich animal feeds, chemical feedstocks (e.g. bioplastic precursors) and higher-value products. This review focuses on the selection, breeding and engineering of microalgae for improved biomass and biofuel conversion efficiencies.
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Affiliation(s)
- Anthony W D Larkum
- Climate Change Cluster, University of Technology (Sydney), Broadway, NSW 2007, Australia.
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44
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Yan C, Schofield O, Dubinsky Z, Mauzerall D, Falkowski PG, Gorbunov MY. Photosynthetic energy storage efficiency in Chlamydomonas reinhardtii, based on microsecond photoacoustics. PHOTOSYNTHESIS RESEARCH 2011; 108:215-224. [PMID: 21894460 DOI: 10.1007/s11120-011-9682-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 08/15/2011] [Indexed: 05/31/2023]
Abstract
Using a novel, pulsed micro-second time-resolved photoacoustic (PA) instrument, we measured thermal dissipation and energy storage (ES) in the intact cells of wild type (WT) Chlamydomonas reinhardtii, and mutants lacking either PSI or PSII reaction centers (RCs). On this time scale, the kinetic contributions of the thermal expansion component due to heat dissipation of absorbed energy and the negative volume change due to electrostriction induced by charge separation in each of the photosystems could be readily distinguished. Kinetic analysis revealed that PSI and PSII RCs exhibit strikingly different PA signals where PSI is characterized by a strong electrostriction signal and a weak thermal expansion component while PSII has a small electrostriction component and large thermal expansion. The calculated ES efficiencies at ~10 μs were estimated to be 80 ± 5 and 50 ± 13% for PSII-deficient mutants and PSI-deficient mutants, respectively, and 67 ± 2% for WT. The overall ES efficiency was positively correlated with the ratio of PSI to PSI + PSII. Our results suggest that the shallow excitonic trap in PSII limits the efficiency of ES as a result of an evolutionary frozen metabolic framework of two photosystems in all oxygenic photoautotrophs.
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Affiliation(s)
- Chengyi Yan
- Environmental Biophysics and Molecular Ecology Program, Institute of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
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Srirangan K, Pyne ME, Perry Chou C. Biochemical and genetic engineering strategies to enhance hydrogen production in photosynthetic algae and cyanobacteria. BIORESOURCE TECHNOLOGY 2011; 102:8589-8604. [PMID: 21514821 DOI: 10.1016/j.biortech.2011.03.087] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 03/24/2011] [Accepted: 03/25/2011] [Indexed: 05/30/2023]
Abstract
As an energy carrier, hydrogen gas is a promising substitute to carbonaceous fuels owing to its superb conversion efficiency, non-polluting nature, and high energy content. At present, hydrogen is predominately synthesized via chemical reformation of fossil fuels. While various biological methods have been extensively explored, none of them is justified as economically feasible. A sustainable platform for biological production of hydrogen will certainly impact the biofuel market. Among a selection of biological systems, algae and cyanobacteria have garnered major interests as potential cell factories for hydrogen production. In conjunction with photosynthesis, these organisms utilize inexpensive inorganic substrates and solar energy for simultaneous biosynthesis and hydrogen evolution. However, the hydrogen yield associated with these organisms remains far too low to compete with the existing chemical systems. This article reviews recent advances of biochemical, bioprocess, and genetic engineering strategies in circumventing technological limitations to hopefully improve the applicative potential of these photosynthetic hydrogen production systems.
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Affiliation(s)
- Kajan Srirangan
- Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
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Bonente G, Formighieri C, Mantelli M, Catalanotti C, Giuliano G, Morosinotto T, Bassi R. Mutagenesis and phenotypic selection as a strategy toward domestication of Chlamydomonas reinhardtii strains for improved performance in photobioreactors. PHOTOSYNTHESIS RESEARCH 2011; 108:107-20. [PMID: 21547493 DOI: 10.1007/s11120-011-9660-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Accepted: 04/24/2011] [Indexed: 05/11/2023]
Abstract
Microalgae have a valuable potential for biofuels production. As a matter of fact, algae can produce different molecules with high energy content, including molecular hydrogen (H(2)) by the activity of a chloroplastic hydrogenase fueled by reducing power derived from water and light energy. The efficiency of this reaction, however, is limited and depends from an intricate relationships between oxygenic photosynthesis and mitochondrial respiration. The way toward obtaining algal strains with high productivity in photobioreactors requires engineering of their metabolism at multiple levels in a process comparable to domestication of crops that were derived from their wild ancestors through accumulation of genetic traits providing improved productivity under conditions of intensive cultivation as well as improved nutritional/industrial properties. This holds true for the production of any biofuels from algae: there is the need to isolate multiple traits to be combined and produce organisms with increased performances. Among the different limitations in H(2) productivity, we identified three with a major relevance, namely: (i) the light distribution through the mass culture; (ii) the strong sensitivity of the hydrogenase to even very low oxygen concentrations; and (iii) the presence of alternative pathways, such as the cyclic electron transport, competing for reducing equivalents with hydrogenase and H(2) production. In order to identify potentially favorable mutations, we generated a collection of random mutants in Chlamydomonas reinhardtii which were selected through phenotype analysis for: (i) a reduced photosynthetic antenna size, and thus a lower culture optical density; (ii) an altered photosystem II activity as a tool to manipulate the oxygen concentration within the culture; and (iii) State 1-State 2 transition mutants, for a reduced cyclic electron flow and maximized electrons flow toward the hydrogenase. Such a broad approach has been possible thanks to the high throughput application of absorption/fluorescence optical spectroscopy methods. Strong and weak points of this approach are discussed.
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Affiliation(s)
- Giulia Bonente
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134, Verona, Italy
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Chlorophyll cycle regulates the construction and destruction of the light-harvesting complexes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1807:968-76. [PMID: 21216224 DOI: 10.1016/j.bbabio.2011.01.002] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 12/24/2010] [Accepted: 01/04/2011] [Indexed: 11/20/2022]
Abstract
Chlorophyll a and chlorophyll b are the major constituents of the photosynthetic apparatus in land plants and green algae. Chlorophyll a is essential in photochemistry, while chlorophyll b is apparently dispensable for their photosynthesis. Instead, chlorophyll b is necessary for stabilizing the major light-harvesting chlorophyll-binding proteins. Chlorophyll b is synthesized from chlorophyll a and is catabolized after it is reconverted to chlorophyll a. This interconversion system between chlorophyll a and chlorophyll b refers to the chlorophyll cycle. The chlorophyll b levels are determined by the activity of the three enzymes participating in the chlorophyll cycle, namely, chlorophyllide a oxygenase, chlorophyll b reductase, and 7-hydroxymethyl-chlorophyll reductase. This article reviews the recent progress on the analysis of the chlorophyll cycle and its enzymes. In particular, we emphasize the impact of genetic modification of chlorophyll cycle enzymes on the construction and destruction of the photosynthetic machinery. These studies reveal that plants regulate the construction and destruction of a specific subset of light-harvesting complexes through the chlorophyll cycle. This article is part of a Special Issue entitled: Regulation of Electron Transport in Chloroplasts.
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Scott SA, Davey MP, Dennis JS, Horst I, Howe CJ, Lea-Smith DJ, Smith AG. Biodiesel from algae: challenges and prospects. Curr Opin Biotechnol 2010; 21:277-86. [DOI: 10.1016/j.copbio.2010.03.005] [Citation(s) in RCA: 633] [Impact Index Per Article: 45.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2010] [Accepted: 03/08/2010] [Indexed: 10/19/2022]
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Mitra M, Melis A. Genetic and biochemical analysis of the TLA1 gene in Chlamydomonas reinhardtii. PLANTA 2010; 231:729-40. [PMID: 20012986 PMCID: PMC2806527 DOI: 10.1007/s00425-009-1083-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2009] [Accepted: 11/24/2009] [Indexed: 05/04/2023]
Abstract
The Chlamydomonas reinhardtii genomic DNA database contains a predicted open reading frame (ORF-P) without an apparent stop-codon and unknown coding sequence, located in close proximity and immediately upstream of the TLA1 gene (GenBank Accession No. AF534570). The latter was implicated in the regulation of the light-harvesting chlorophyll antenna size of photosynthesis (Tetali et al. Planta 225:813-829, 2007). To provide currently lacking information on ORF-P and its potential participation in TLA1 gene expression, thus in the regulation of the chlorophyll antenna size, genetic and biochemical analyses were undertaken. The coding and UTR regions of the ORF-P were defined and delineated from those of the adjacent TLA1 gene. ORF-P is shown to encode a protein with a distinct RING-like zinc finger domain that is present in numerous eukaryotic proteins, believed to play a role in cellular ubiquitination, leading to regulation of cellular processes like signaling, growth, transcription, and DNA repair. It is further shown that the two genes share a 74-bp overlap between the 3' UTR region of ORF-P and the 5' UTR region of TLA1. However, they possess distinct start and stop codons and separate coding sequences, and transcribed as separate mRNAs without any trans-splicing between them. Complementation experiments showed that the TLA1 gene alone is sufficient to rescue the truncated chlorophyll antenna size phenotype of the tla1 mutant. Protein sequence alignments in C. reinhardtii and the colorless microalga Polytomella parva suggested that TLA1 defines the relationship between nucleus and organelle in microalgae, indirectly affecting the development of the chlorophyll antenna size.
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Affiliation(s)
- Mautusi Mitra
- Department of Plant and Microbial Biology, University of California, 111 Koshland Hall MC-3102, Berkeley, CA 94720-3102 USA
| | - Anastasios Melis
- Department of Plant and Microbial Biology, University of California, 111 Koshland Hall MC-3102, Berkeley, CA 94720-3102 USA
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Hansson A, Jensen PE. Chlorophyll limitation in plants remodels and balances the photosynthetic apparatus by changing the accumulation of photosystems I and II through two different approaches. PHYSIOLOGIA PLANTARUM 2009; 135:214-228. [PMID: 19055541 DOI: 10.1111/j.1399-3054.2008.01181.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Arabidopsis plants with a reduced expression of CHL27 (chl27), an enzyme (EC 1.14.13.81) required for the synthesis of Pchlide, are chlorotic and have a Chl a/b ratio two times higher than wild-type (WT). Knockdown plants transformed with a construct constitutively expressing CHL27 recovered regarding Chl level, a/b ratio and 77K fluorescence. A negative correlation was found between total Chl and Chl a/b ratio in the examined plants. The chl27 plants fail to assemble WT amounts of complete PSI and PSII, leading to an elevated PSII/PSI ratio. The PSI remaining in chl27 is fully functional with a quantum yield higher than for WT. Despite a severe reduction of photosystem II antennae protein (LHCII) and an increased proportion of stroma lammella, the chl27 plants are able to perform state transitions. No major differences were found regarding PSII quantum yield, qN and 1 - qp whereas non-photochemical quenching was decreased by a factor two in chl27 plants. The PSII quantum yield for dark-adapted plants and plants given 10 min recovery after high light treatment were similar for both WT and chl27 showing that chl27 plants are not more susceptible to photoinhibition than WT. Taken together the plant manage to acclimate and to balance the two photosystems well even when it is severely limited in Chl. The way to achieve this differs for the two photosystems: regarding PSI a general reduction of core and antenna subunits occurs with no apparent change in the antenna composition; whereas for PSII there is a preferential loss of antenna proteins.
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Affiliation(s)
- Andreas Hansson
- Molecular Plant Biology Laboratory, Department of Plant Biology and Biotechnology, Faculty of Life Sciences, VKR Research Centre Pro-Active Plants, University of Copenhagen, 40 Thorvaldsensvej, Frederiksberg C, Denmark
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