1
|
Polanco EA, Opdam LV, Passerini L, Huber M, Bonnet S, Pandit A. An artificial metalloenzyme that can oxidize water photocatalytically: design, synthesis, and characterization. Chem Sci 2024; 15:3596-3609. [PMID: 38455019 PMCID: PMC10915814 DOI: 10.1039/d3sc05870k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 01/29/2024] [Indexed: 03/09/2024] Open
Abstract
In nature, light-driven water oxidation (WO) catalysis is performed by photosystem II via the delicate interplay of different cofactors positioned in its protein scaffold. Artificial systems for homogeneous photocatalytic WO are based on small molecules that often have limited solubility in aqueous solutions. In this work, we alleviated this issue and present a cobalt-based WO-catalyst containing artificial metalloenzyme (ArM) that is active in light-driven, homogeneous WO catalysis in neutral-pH aqueous solutions. A haem-containing electron transfer protein, cytochrome B5 (CB5), served to host a first-row transition-metal-based WO catalyst, CoSalen (CoIISalen, where H2Salen = N,N'-bis(salicylidene)ethylenediamine), thus producing an ArM capable of driving photocatalytic WO. The CoSalen ArM formed a water-soluble pre-catalyst in the presence of [Ru(bpy)3](ClO4)2 as photosensitizer and Na2S2O8 as the sacrificial electron acceptor, with photocatalytic activity similar to that of free CoSalen. During photocatalysis, the CoSalen-protein interactions were destabilized, and the protein partially unfolded. Rather than forming tens of nanometer sized CoOx nanoparticles as free CoSalen does under photocatalytic WO conditions, the CB5 : CoSalen ArM showed limited protein cross-linking and remained soluble. We conclude that a weak, dynamic interaction between a soluble cobalt species and apoCB5 was formed, which generated a catalytically active adduct during photocatalysis. A detailed analysis was performed on protein stability and decomposition processes during the harsh oxidizing reaction conditions of WO, which will serve for the future design of WO ArMs with improved activity and stability.
Collapse
Affiliation(s)
- Ehider A Polanco
- Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2333 CC Leiden The Netherlands
| | - Laura V Opdam
- Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2333 CC Leiden The Netherlands
| | - Leonardo Passerini
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University Niels Bohrweg 2 2333 CA Leiden The Netherlands
| | - Martina Huber
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University Niels Bohrweg 2 2333 CA Leiden The Netherlands
| | - Sylvestre Bonnet
- Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2333 CC Leiden The Netherlands
| | - Anjali Pandit
- Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2333 CC Leiden The Netherlands
| |
Collapse
|
2
|
Marulanda Valencia W, Pandit A. Photosystem II Subunit S (PsbS): A Nano Regulator of Plant Photosynthesis. J Mol Biol 2024; 436:168407. [PMID: 38109993 DOI: 10.1016/j.jmb.2023.168407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/26/2023] [Accepted: 12/13/2023] [Indexed: 12/20/2023]
Abstract
Light is required for photosynthesis, but plants are often exposed to excess light, which can lead to photodamage and eventually cell death. To prevent this, they evolved photoprotective feedback mechanisms that regulate photosynthesis and trigger processes that dissipate light energy as heat, called non-photochemical quenching (NPQ). In excess light conditions, the light reaction and activity of Photosystem II (PSII) generates acidification of the thylakoid lumen, which is sensed by special pH-sensitive proteins called Photosystem II Subunit S (PsbS), actuating a photoprotective "switch" in the light-harvesting antenna. Despite its central role in regulating photosynthetic energy conversion, the molecular mechanism of PsbS as well as its interaction with partner proteins are not well understood. This review summarizes the current knowledge on the molecular structure and mechanistic aspects of the light-stress sensor PsbS and addresses open questions and challenges in the field regarding a full understanding of its functional mechanism and role in NPQ.
Collapse
Affiliation(s)
| | - Anjali Pandit
- Leiden Inst. of Chemistry, Gorlaeus Laboratory, Einsteinweg 55, 2300 RA Leiden, The Netherlands.
| |
Collapse
|
3
|
Yin H, Perera-Castro AV, Randall KL, Turnbull JD, Waterman MJ, Dunn J, Robinson SA. Basking in the sun: how mosses photosynthesise and survive in Antarctica. PHOTOSYNTHESIS RESEARCH 2023; 158:151-169. [PMID: 37515652 PMCID: PMC10684656 DOI: 10.1007/s11120-023-01040-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 07/10/2023] [Indexed: 07/31/2023]
Abstract
The Antarctic environment is extremely cold, windy and dry. Ozone depletion has resulted in increasing ultraviolet-B radiation, and increasing greenhouse gases and decreasing stratospheric ozone have altered Antarctica's climate. How do mosses thrive photosynthetically in this harsh environment? Antarctic mosses take advantage of microclimates where the combination of protection from wind, sufficient melt water, nutrients from seabirds and optimal sunlight provides both photosynthetic energy and sufficient warmth for efficient metabolism. The amount of sunlight presents a challenge: more light creates warmer canopies which are optimal for photosynthetic enzymes but can contain excess light energy that could damage the photochemical apparatus. Antarctic mosses thus exhibit strong photoprotective potential in the form of xanthophyll cycle pigments. Conversion to zeaxanthin is high when conditions are most extreme, especially when water content is low. Antarctic mosses also produce UV screening compounds which are maintained in cell walls in some species and appear to protect from DNA damage under elevated UV-B radiation. These plants thus survive in one of the harshest places on Earth by taking advantage of the best real estate to optimise their metabolism. But survival is precarious and it remains to be seen if these strategies will still work as the Antarctic climate changes.
Collapse
Affiliation(s)
- Hao Yin
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, NSW, 2522, Australia
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia
| | | | - Krystal L Randall
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, NSW, 2522, Australia
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Johanna D Turnbull
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, NSW, 2522, Australia
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Melinda J Waterman
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, NSW, 2522, Australia
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Jodie Dunn
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, NSW, 2522, Australia
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Sharon A Robinson
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, NSW, 2522, Australia.
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia.
| |
Collapse
|
4
|
Shao Z, Wang S, Liu N, Wang W, Zhu L. Interactions between sulfonamide homologues and glycosyltransferase induced metabolic disorders in rice (Oryza sativa L.). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 336:122486. [PMID: 37669699 DOI: 10.1016/j.envpol.2023.122486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 07/24/2023] [Accepted: 08/30/2023] [Indexed: 09/07/2023]
Abstract
Sulfadiazine and its derivatives (sulfonamides, SAs) could induce distinct biotoxic, metabolic and physiological abnormalities, potentially due to their subtle structural differences. This study conducted an in-depth investigation on the interactions between SA homologues, i.e. sulfadiazine (SD), sulfamerazine (SD1), and sulfamethazine (SD2), and the key metabolic enzyme (glycosyltransferase, GT) in rice (Oryza sativa L.). Untargeted screening of SA metabolites revealed that GT-catalyzed glycosylation was the primary transformation pathway of SAs in rice. Molecular docking identified that the binding sites of SAs on GT (D0TZD6) were responsible for transferring sugar moiety to synthesize polysaccharides and detoxify SAs. Specifically, amino acids in the GT-binding cavity (e.g., GLY487 and CYS486) formed stable hydrogen bonds with SAs (e.g., the sulfonamide group of SD). Molecular dynamics simulations revealed that SAs induced conformational changes in GT ligand binding domain, which was supported by the significantly decreased GT activity and gene expression level. As evidenced by proteomics and metabolomics, SAs inhibited the transfer and synthesis of sugar but stimulated sugar decomposition in rice leaves, leading to the accumulation of mono- and disaccharides in rice leaves. While the differences in the increased sugar content by SD (24.3%, compared with control), SD1 (11.1%), and SD2 (6.24%) can be attributed to their number of methyl groups (0, 1, 2, respectively), which determined the steric hindrance and hydrogen bonds formation with GT. This study suggested that the disturbances on crop sugar metabolism by homologues contaminants are determined by the interaction between the contaminants and the target enzyme, and are greatly dependent on the steric hindrance effects contributed by their side chains. The results are of importance to identify priority pollutants and ensure crop quality in contaminated fields.
Collapse
Affiliation(s)
- Zexi Shao
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang, 310058, China
| | - Shuyuan Wang
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang, 310058, China
| | - Na Liu
- College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China
| | - Wei Wang
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang, 310058, China
| | - Lizhong Zhu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang, 310058, China.
| |
Collapse
|
5
|
Ptushenko VV, Knorre DD, Glagoleva ES. The Photoprotective Protein PsbS from Green Microalga Lobosphaera incisa: The Amino Acid Sequence, 3D Structure and Probable pH-Sensitive Residues. Int J Mol Sci 2023; 24:15060. [PMID: 37894741 PMCID: PMC10606523 DOI: 10.3390/ijms242015060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 10/04/2023] [Accepted: 10/09/2023] [Indexed: 10/29/2023] Open
Abstract
PsbS is one of the key photoprotective proteins, ensuring the tolerance of the photosynthetic apparatus (PSA) of a plant to abrupt changes in irradiance. Being a component of photosystem II, it provides the formation of quenching centers for excited states of chlorophyll in the photosynthetic antenna with an excess of light energy. The signal for "turning on" the photoprotective function of the protein is an excessive decrease in pH in the thylakoid lumen occurring when all the absorbed light energy (stored in the form of transmembrane proton potential) cannot be used for carbon assimilation. Hence, lumen-exposed protonatable amino acid residues that could serve as pH sensors are the essential components of PsbS-dependent photoprotection, and their pKa values are necessary to describe it. Previously, calculations of the lumen-exposed protonatable residue pKa values in PsbS from spinach were described in the literature. However, it has recently become clear that PsbS, although typical of higher plants and charophytes, can also provide photoprotection in green algae. Namely, the stress-induced expression of PsbS was recently shown for two green microalgae species: Chlamydomonas reinhardtii and Lobosphaera incisa. Therefore, we determined the amino acid sequence and modeled the three-dimensional structure of the PsbS from L. incisa, as well as calculated the pKa values of its lumen-exposed protonatable residues. Despite significant differences in amino acid sequence, proteins from L. incisa and Spinacia oleracea have similar three-dimensional structures. Along with the other differences, one of the two pH-sensing glutamates in PsbS from S. oleracea (namely, Glu-173) has no analogue in L. incisa protein. Moreover, there are only four glutamate residues in the lumenal region of the L. incisa protein, while there are eight glutamates in S. oleracea. However, our calculations show that, despite the relative deficiency in protonatable residues, at least two residues of L. incisa PsbS can be considered probable pH sensors: Glu-87 and Lys-196.
Collapse
Affiliation(s)
- Vasily V. Ptushenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Russia
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Dmitry D. Knorre
- Faculty of Computational Mathematics and Cybernetics, Lomonosov Moscow State University, 119992 Moscow, Russia
| | - Elena S. Glagoleva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Russia
- Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
| |
Collapse
|
6
|
Salah L, Makhseed S, Ghazal B, Abdel Nazeer A, Etherington MK, Ponseca CS, Li C, Monkman AP, Danos A, Shuaib A. Covalently linked pyrene antennas for optically dense yet aggregation-resistant light-harvesting systems. Phys Chem Chem Phys 2023; 25:24878-24882. [PMID: 37681234 DOI: 10.1039/d3cp02586a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
In this study we present a novel energy transfer material inspired by natural light-harvesting antenna arrays, zinc(II) phthalocyanine-pyrene (ZnPcPy). The ZnPcPy system facilitates energy transfer from 16 covalently linked pyrene (Py) donor chromophores to the emissive central zinc(II) phthalocyanine (ZnPc) core. Nearly 98% energy transfer efficiency is determined from the changes in emission decay rates between free MePy to covalently linked Py, supported by comparisons of photoluminescence quantum yields using different excitation wavelengths. A comparative analysis of ZnPcPy and an equivalent mixture of ZnPc and MePy demonstrates the superior light-harvesting performance of the covalently linked system, with energy transfer rates 9705 times higher in the covalently bound system. This covalent strategy allows for very high loadings of absorbing Py chromophores to be achieved while also avoiding exciton quenching that would otherwise arise, with the same strategy widely applicable to other pairs of Főrster resonance energy transfer (FRET) chromophores.
Collapse
Affiliation(s)
- Lubna Salah
- Department of Chemistry, Faculty of Science, Kuwait University, P. O. Box 5969, Safat 13060, Kuwait
| | - Saad Makhseed
- Department of Chemistry, Faculty of Science, Kuwait University, P. O. Box 5969, Safat 13060, Kuwait
| | - Basma Ghazal
- Organometallic and Organometalloid Chemistry Department, National Research Centre, Giza, Egypt
| | - Ahmed Abdel Nazeer
- Organometallic and Organometalloid Department, National Research Centre, Dokki, Cairo, 12622, Egypt
| | - Marc K Etherington
- Department of Mathematics, Physics & Electrical Engineering, Northumbria University, Ellison Place, Newcastle upon Tyne, NE1 8ST, UK
| | - Carlito S Ponseca
- Mathematics and Natural Science Department, Gulf University for Science and Technology, Kuwait
| | - Chunyong Li
- Department of Physics, Durham University, South Road, Durham, DH1 3LE, UK.
| | - Andrew P Monkman
- Department of Physics, Durham University, South Road, Durham, DH1 3LE, UK.
| | - Andrew Danos
- Department of Physics, Durham University, South Road, Durham, DH1 3LE, UK.
| | - Ali Shuaib
- Biomedical Engineering Unit, Department of Physiology, Faculty of Medicine, Kuwait University, P. O. Box 24923, Safat 13110, Kuwait.
| |
Collapse
|
7
|
Cui J, Qiu T, Li L, Cui S. De novo full-length transcriptome analysis of two ecotypes of Phragmites australis (swamp reed and dune reed) provides new insights into the transcriptomic complexity of dune reed and its long-term adaptation to desert environments. BMC Genomics 2023; 24:180. [PMID: 37020272 PMCID: PMC10077656 DOI: 10.1186/s12864-023-09271-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 03/23/2023] [Indexed: 04/07/2023] Open
Abstract
BACKGROUND The extremely harsh environment of the desert is changing dramatically every moment, and the rapid adaptive stress response in the short term requires enormous energy expenditure to mobilize widespread regulatory networks, which is all the more detrimental to the survival of the desert plants themselves. The dune reed, which has adapted to desert environments with complex and variable ecological factors, is an ideal type of plant for studying the molecular mechanisms by which Gramineae plants respond to combinatorial stress of the desert in their natural state. But so far, the data on the genetic resources of reeds is still scarce, therefore most of their research has focused on ecological and physiological studies. RESULTS In this study, we obtained the first De novo non-redundant Full-Length Non-Chimeric (FLNC) transcriptome databases for swamp reeds (SR), dune reeds (DR) and the All of Phragmites australis (merged of iso-seq data from SR and DR), using PacBio Iso-Seq technology and combining tools such as Iso-Seq3 and Cogent. We then identified and described long non-coding RNAs (LncRNA), transcription factor (TF) and alternative splicing (AS) events in reeds based on a transcriptome database. Meanwhile, we have identified and developed for the first time a large number of candidates expressed sequence tag-SSR (EST-SSRs) markers in reeds based on UniTransModels. In addition, through differential gene expression analysis of wild-type and homogenous cultures, we found a large number of transcription factors that may be associated with desert stress tolerance in the dune reed, and revealed that members of the Lhc family have an important role in the long-term adaptation of dune reeds to desert environments. CONCLUSIONS Our results provide a positive and usable genetic resource for Phragmites australis with a widespread adaptability and resistance, and provide a genetic database for subsequent reeds genome annotation and functional genomic studies.
Collapse
Affiliation(s)
- Jipeng Cui
- College of Life Sciences, Capital Normal University, Haidian District, Beijing, 100048, China
- Beijing Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement, Haidian District, Beijing, 100048, China
| | - Tianhang Qiu
- College of Life Sciences, Capital Normal University, Haidian District, Beijing, 100048, China
- Beijing Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement, Haidian District, Beijing, 100048, China
| | - Li Li
- College of Life Sciences, Capital Normal University, Haidian District, Beijing, 100048, China
- Beijing Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement, Haidian District, Beijing, 100048, China
| | - Suxia Cui
- College of Life Sciences, Capital Normal University, Haidian District, Beijing, 100048, China.
- Beijing Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement, Haidian District, Beijing, 100048, China.
| |
Collapse
|
8
|
LHC-like Proteins: The Guardians of Photosynthesis. Int J Mol Sci 2023; 24:ijms24032503. [PMID: 36768826 PMCID: PMC9916820 DOI: 10.3390/ijms24032503] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/18/2023] [Accepted: 01/20/2023] [Indexed: 02/03/2023] Open
Abstract
The emergence of chlorophyll-containing light-harvesting complexes (LHCs) was a crucial milestone in the evolution of photosynthetic eukaryotic organisms. Light-harvesting chlorophyll-binding proteins form complexes in proximity to the reaction centres of photosystems I and II and serve as an antenna, funnelling the harvested light energy towards the reaction centres, facilitating photochemical quenching, thereby optimizing photosynthesis. It is now generally accepted that the LHC proteins evolved from LHC-like proteins, a diverse family of proteins containing up to four transmembrane helices. Interestingly, LHC-like proteins do not participate in light harvesting to elevate photosynthesis activity under low light. Instead, they protect the photosystems by dissipating excess energy and taking part in non-photochemical quenching processes. Although there is evidence that LHC-like proteins are crucial factors of photoprotection, the roles of only a few of them, mainly the stress-related psbS and lhcSR, are well described. Here, we summarize the knowledge gained regarding the evolution and function of the various LHC-like proteins, with emphasis on those strongly related to photoprotection. We further suggest LHC-like proteins as candidates for improving photosynthesis in significant food crops and discuss future directions in their research.
Collapse
|
9
|
Kato S, Misumi O, Maruyama S, Nozaki H, Tsujimoto-Inui Y, Takusagawa M, Suzuki S, Kuwata K, Noda S, Ito N, Okabe Y, Sakamoto T, Yagisawa F, Matsunaga TM, Matsubayashi Y, Yamaguchi H, Kawachi M, Kuroiwa H, Kuroiwa T, Matsunaga S. Genomic analysis of an ultrasmall freshwater green alga, Medakamo hakoo. Commun Biol 2023; 6:89. [PMID: 36690657 PMCID: PMC9871001 DOI: 10.1038/s42003-022-04367-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 12/12/2022] [Indexed: 01/24/2023] Open
Abstract
Ultrasmall algae have attracted the attention of biologists investigating the basic mechanisms underlying living systems. Their potential as effective organisms for producing useful substances is also of interest in bioindustry. Although genomic information is indispensable for elucidating metabolism and promoting molecular breeding, many ultrasmall algae remain genetically uncharacterized. Here, we present the nuclear genome sequence of an ultrasmall green alga of freshwater habitats, Medakamo hakoo. Evolutionary analyses suggest that this species belongs to a new genus within the class Trebouxiophyceae. Sequencing analyses revealed that its genome, comprising 15.8 Mbp and 7629 genes, is among the smallest known genomes in the Viridiplantae. Its genome has relatively few genes associated with genetic information processing, basal transcription factors, and RNA transport. Comparative analyses revealed that 1263 orthogroups were shared among 15 ultrasmall algae from distinct phylogenetic lineages. The shared gene sets will enable identification of genes essential for algal metabolism and cellular functions.
Collapse
Affiliation(s)
- Shoichi Kato
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, 278-8510, Japan
| | - Osami Misumi
- Department of Biological Science and Chemistry, Faculty of Science, Graduate School of Medicine, Yamaguchi University, Yoshida, Yamaguchi, 753-8512, Japan
| | - Shinichiro Maruyama
- Department of Ecological Developmental Adaptability Life Sciences, Graduate School of Life Sciences, Tohoku University, Aobaku, Sendai, 980-8578, Japan
- Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo, 112-8610, Japan
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, 277-8562, Japan
| | - Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo, Tokyo, 113-0033, Japan
- Biodiversity Division, National Institute for Environmental Studies, Onogawa, Tsukuba, Ibaraki, 305-8506, Japan
| | - Yayoi Tsujimoto-Inui
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, 277-8562, Japan
| | - Mari Takusagawa
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan
| | - Shigekatsu Suzuki
- Biodiversity Division, National Institute for Environmental Studies, Onogawa, Tsukuba, Ibaraki, 305-8506, Japan
| | - Keiko Kuwata
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya, 464-8602, Japan
| | - Saki Noda
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Nanami Ito
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, 277-8562, Japan
| | - Yoji Okabe
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, 277-8562, Japan
| | - Takuya Sakamoto
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, 278-8510, Japan
| | - Fumi Yagisawa
- Center for Research Advancement and Collaboration, University of the Ryukyus, Okinawa, 903-0213, Japan
- Graduate School of Engineering and Science, University of the Ryukyus, Okinawa, 903-0213, Japan
| | - Tomoko M Matsunaga
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, 277-8562, Japan
| | - Yoshikatsu Matsubayashi
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Haruyo Yamaguchi
- Biodiversity Division, National Institute for Environmental Studies, Onogawa, Tsukuba, Ibaraki, 305-8506, Japan
| | - Masanobu Kawachi
- Biodiversity Division, National Institute for Environmental Studies, Onogawa, Tsukuba, Ibaraki, 305-8506, Japan
| | - Haruko Kuroiwa
- Department of Chemical and Biological Science, Faculty of Science, Japan Women's University, Tokyo, 112-8681, Japan
| | - Tsuneyoshi Kuroiwa
- Department of Chemical and Biological Science, Faculty of Science, Japan Women's University, Tokyo, 112-8681, Japan.
| | - Sachihiro Matsunaga
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, 278-8510, Japan.
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, 277-8562, Japan.
| |
Collapse
|
10
|
Ptushenko VV, Bondarenko GN, Vinogradova EN, Glagoleva ES, Karpova OV, Ptushenko OS, Shibzukhova KA, Solovchenko AE, Lobakova ES. Chilling Upregulates Expression of the PsbS and LhcSR Genes in the Chloroplasts of the Green Microalga Lobosphaera incisa IPPAS C-2047. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:1699-1706. [PMID: 36717458 DOI: 10.1134/s0006297922120240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Non-photochemical quenching (NPQ) of excited chlorophyll states is essential for protecting the photosynthetic apparatus (PSA) from the excessive light-induced damage in all groups of oxygenic photosynthetic organisms. The key component of the NPQ mechanism in green algae and some other groups of algae and mosses is the LhcSR protein of the light harvesting complex (LHC) protein superfamily. In vascular plants, LhcSR is replaced by PsbS, another member of the LHC superfamily and a subunit of photosystem II (PSII). PsbS also performs the photoprotective function in mosses. For a long time, PsbS had been believed to be nonfunctional in green algae, although the corresponding gene was discovered in the genome of these organisms. The first evidence of the PsbS accumulation in the model green alga Chlamydomonas reinhardtii in response to the increase in irradiance was obtained only six years ago. However, the observed increase in the PsbS content was short-termed (on an hour-timescale). Here, we report a significant (more than three orders of magnitude) and prolonged (four days) upregulation of PsbS expression in response to the chilling-induced high-light stress followed by a less significant (~ tenfold) increase in the PsbS expression for nine days. This is the first evidence for the long-term upregulation of the PsbS expression in green alga (Chlorophyta) in response to stress. Our data indicate that the role of PsbS in the PSA of Chlorophyta is not limited to the first-line defense against stress, as it was previously assumed, but includes full-scale participation in the photoprotection of PSA from the environmental stress factors.
Collapse
Affiliation(s)
- Vasily V Ptushenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia. .,Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, 119334, Russia
| | | | - Elizaveta N Vinogradova
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.,Kurchatov Institute National Research Center, 123182 Moscow Russia
| | - Elena S Glagoleva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia.,Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Olga V Karpova
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Oxana S Ptushenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia.,Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Karina A Shibzukhova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia.,Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Alexei E Solovchenko
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.,Pskov State University, Pskov, 128000, Russia
| | - Elena S Lobakova
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| |
Collapse
|
11
|
Davies KM, Landi M, van Klink JW, Schwinn KE, Brummell DA, Albert NW, Chagné D, Jibran R, Kulshrestha S, Zhou Y, Bowman JL. Evolution and function of red pigmentation in land plants. ANNALS OF BOTANY 2022; 130:613-636. [PMID: 36070407 PMCID: PMC9670752 DOI: 10.1093/aob/mcac109] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 09/05/2022] [Indexed: 05/10/2023]
Abstract
BACKGROUND Land plants commonly produce red pigmentation as a response to environmental stressors, both abiotic and biotic. The type of pigment produced varies among different land plant lineages. In the majority of species they are flavonoids, a large branch of the phenylpropanoid pathway. Flavonoids that can confer red colours include 3-hydroxyanthocyanins, 3-deoxyanthocyanins, sphagnorubins and auronidins, which are the predominant red pigments in flowering plants, ferns, mosses and liverworts, respectively. However, some flowering plants have lost the capacity for anthocyanin biosynthesis and produce nitrogen-containing betalain pigments instead. Some terrestrial algal species also produce red pigmentation as an abiotic stress response, and these include both carotenoid and phenolic pigments. SCOPE In this review, we examine: which environmental triggers induce red pigmentation in non-reproductive tissues; theories on the functions of stress-induced pigmentation; the evolution of the biosynthetic pathways; and structure-function aspects of different pigment types. We also compare data on stress-induced pigmentation in land plants with those for terrestrial algae, and discuss possible explanations for the lack of red pigmentation in the hornwort lineage of land plants. CONCLUSIONS The evidence suggests that pigment biosynthetic pathways have evolved numerous times in land plants to provide compounds that have red colour to screen damaging photosynthetically active radiation but that also have secondary functions that provide specific benefits to the particular land plant lineage.
Collapse
Affiliation(s)
| | - Marco Landi
- Department of Agriculture, Food and Environment, University of Pisa, Italy
| | - John W van Klink
- The New Zealand Institute for Plant and Food Research Limited, Department of Chemistry, Otago University, Dunedin, New Zealand
| | - Kathy E Schwinn
- The New Zealand Institute for Plant and Food Research Limited, Private Bag 11600, Palmerston North 4442, New Zealand
| | - David A Brummell
- The New Zealand Institute for Plant and Food Research Limited, Private Bag 11600, Palmerston North 4442, New Zealand
| | - Nick W Albert
- The New Zealand Institute for Plant and Food Research Limited, Private Bag 11600, Palmerston North 4442, New Zealand
| | - David Chagné
- The New Zealand Institute for Plant and Food Research Limited, Private Bag 11600, Palmerston North 4442, New Zealand
| | - Rubina Jibran
- The New Zealand Institute for Plant and Food Research Limited, Private Bag 92169, Auckland Mail Centre, Auckland 1142, New Zealand
| | - Samarth Kulshrestha
- The New Zealand Institute for Plant and Food Research Limited, Private Bag 11600, Palmerston North 4442, New Zealand
| | - Yanfei Zhou
- The New Zealand Institute for Plant and Food Research Limited, Private Bag 11600, Palmerston North 4442, New Zealand
| | - John L Bowman
- School of Biological Sciences, Monash University, Melbourne, VIC, Australia
| |
Collapse
|
12
|
Perera-Castro AV, González-Rodríguez ÁM, Fernández-Marín B. When time is not of the essence: constraints to the carbon balance of bryophytes. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:4562-4575. [PMID: 35298628 DOI: 10.1093/jxb/erac104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 03/10/2022] [Indexed: 06/14/2023]
Abstract
The data available so far indicate that the photosynthetic and relative growth rates of bryophytes are 10% of those reported for tracheophytes. By examining the existing literature and reanalysing data published in over 100 studies, this review examines the ecophysiological, biochemical, and structural reasons behind this phenomenon. The limiting Rubisco content and surface for gas exchange are the internal factors that can explain the low photosynthetic and growth rates of bryophytes. The role of the thicker cell walls of bryophytes in limiting CO2 diffusion is unclear, due to the current uncertainties regarding their porosity and permeability to CO2. From this review, it is also evident that, despite bryophytes having low photosynthetic rates, their positive carbon balance is tightly related to their capacity to deal with extreme conditions. Contributing factors include their capacity to deal with large daily temperature oscillations, and their capacity to delay the cessation of photosynthesis under water deficit (or to tolerate desiccation in extreme situations). Although further studies on bryophytes are needed before more solid conclusions can be drawn, it seems that their success relies on their remarkable tolerance to a highly variable environment, possibly at the expense of their maximum photosynthetic rate.
Collapse
Affiliation(s)
- Alicia V Perera-Castro
- Department of Botany, Ecology and Plant Physiology, Universidad de La Laguna, 38200 La Laguna, Canary Islands, Spain
| | - Águeda M González-Rodríguez
- Department of Botany, Ecology and Plant Physiology, Universidad de La Laguna, 38200 La Laguna, Canary Islands, Spain
| | - Beatriz Fernández-Marín
- Department of Botany, Ecology and Plant Physiology, Universidad de La Laguna, 38200 La Laguna, Canary Islands, Spain
| |
Collapse
|
13
|
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.
Collapse
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
| |
Collapse
|
14
|
Photoprotective conformational dynamics of photosynthetic light-harvesting proteins. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148543. [PMID: 35202576 DOI: 10.1016/j.bbabio.2022.148543] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 01/25/2022] [Accepted: 02/15/2022] [Indexed: 11/21/2022]
Abstract
Under high light conditions, excess energy can damage the machinery of oxygenic photosynthesis. Plants have evolved a series of photoprotective processes, including conformational changes of the light-harvesting complexes that activate dissipation of energy as heat. In this mini-review, we will summarize our recent work developing and applying single-molecule methods to investigate the conformational states of the light-harvesting complexes. Through these measurements, we identified dissipative conformations and how they depend on conditions that mimic high light. Our studies revealed an equilibrium between the light-harvesting and dissipative conformations, and that the nature of the equilibrium varies with cellular environment, between proteins, and between species. Finally, we conclude with an outlook on open questions and implications for photosynthetic yields.
Collapse
|
15
|
Structure of the stress-related LHCSR1 complex determined by an integrated computational strategy. Commun Biol 2022; 5:145. [PMID: 35177775 PMCID: PMC8854571 DOI: 10.1038/s42003-022-03083-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 01/25/2022] [Indexed: 11/08/2022] Open
Abstract
Light-harvesting complexes (LHCs) are pigment-protein complexes whose main function is to capture sunlight and transfer the energy to reaction centers of photosystems. In response to varying light conditions, LH complexes also play photoregulation and photoprotection roles. In algae and mosses, a sub-family of LHCs, light-harvesting complex stress-related (LHCSR), is responsible for photoprotective quenching. Despite their functional and evolutionary importance, no direct structural information on LHCSRs is available that can explain their unique properties. In this work, we propose a structural model of LHCSR1 from the moss P. patens, obtained through an integrated computational strategy that combines homology modeling, molecular dynamics, and multiscale quantum chemical calculations. The model is validated by reproducing the spectral properties of LHCSR1. Our model reveals the structural specificity of LHCSR1, as compared with the CP29 LH complex, and poses the basis for understanding photoprotective quenching in mosses. The structure of the moss P. patens light-harvesting complex stress-related 1 (LHCSR1) is determined using a multi-scale computational approach for investigations of its photoprotective function.
Collapse
|
16
|
Size and Fluorescence Properties of Algal Photosynthetic Antenna Proteins Estimated by Microscopy. Int J Mol Sci 2022; 23:ijms23020778. [PMID: 35054961 PMCID: PMC8775774 DOI: 10.3390/ijms23020778] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 12/30/2021] [Accepted: 01/07/2022] [Indexed: 02/04/2023] Open
Abstract
Antenna proteins play a major role in the regulation of light-harvesting in photosynthesis. However, less is known about a possible link between their sizes (oligomerization state) and fluorescence intensity (number of photons emitted). Here, we used a microscopy-based method, Fluorescence Correlation Spectroscopy (FCS), to analyze different antenna proteins at the particle level. The direct comparison indicated that Chromera Light Harvesting (CLH) antenna particles (isolated from Chromera velia) behaved as the monomeric Light Harvesting Complex II (LHCII) (from higher plants), in terms of their radius (based on the diffusion time) and fluorescence yields. FCS data thus indicated a monomeric oligomerization state of algal CLH antenna (at our experimental conditions) that was later confirmed also by biochemical experiments. Additionally, our data provide a proof of concept that the FCS method is well suited to measure proteins sizes (oligomerization state) and fluorescence intensities (photon counts) of antenna proteins per single particle (monomers and oligomers). We proved that antenna monomers (CLH and LHCIIm) are more "quenched" than the corresponding trimers. The FCS measurement thus represents a useful experimental approach that allows studying the role of antenna oligomerization in the mechanism of photoprotection.
Collapse
|
17
|
Non-Photochemical Quenching: From Light Perception to Photoprotective Gene Expression. Int J Mol Sci 2022; 23:ijms23020687. [PMID: 35054872 PMCID: PMC8775618 DOI: 10.3390/ijms23020687] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 01/05/2022] [Accepted: 01/05/2022] [Indexed: 02/06/2023] Open
Abstract
Light is essential for photosynthesis but light levels that exceed an organism's assimilation capacity can cause serious damage or even cell death. Plants and microalgae have developed photoprotective mechanisms collectively referred to as non-photochemical quenching to minimize such potential damage. One such mechanism is energy-dependent quenching (qE), which dissipates excess light energy as heat. Over the last 30 years, much has been learned about the molecular mechanism of qE in green algae and plants. However, the steps between light perception and qE represented a gap in our knowledge until the recent identification of light-signaling pathways that function in these processes in the green alga Chlamydomonas reinhardtii. In this review, we summarize the high light and UV-mediated signaling pathways for qE in Chlamydomonas. We discuss key questions remaining about the pathway from light perception to photoprotective gene expression in Chlamydomonas. We detail possible differences between green algae and plants in light-signaling mechanisms for qE and emphasize the importance of research on light-signaling mechanisms for qE in plants.
Collapse
|
18
|
Serrano-Pérez E, Romero-Losada AB, Morales-Pineda M, García-Gómez ME, Couso I, García-González M, Romero-Campero FJ. Transcriptomic and Metabolomic Response to High Light in the Charophyte Alga Klebsormidium nitens. FRONTIERS IN PLANT SCIENCE 2022; 13:855243. [PMID: 35599877 PMCID: PMC9121098 DOI: 10.3389/fpls.2022.855243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/28/2022] [Indexed: 05/04/2023]
Abstract
The characterization of the molecular mechanisms, such as high light irradiance resistance, that allowed plant terrestralization is a cornerstone in evolutionary studies since the conquest of land by plants played a pivotal role in life evolution on Earth. Viridiplantae or the green lineage is divided into two clades, Chlorophyta and Streptophyta, that in turn splits into Embryophyta or land plants and Charophyta. Charophyta are used in evolutionary studies on plant terrestralization since they are generally accepted as the extant algal species most closely related to current land plants. In this study, we have chosen the facultative terrestrial early charophyte alga Klebsormidium nitens to perform an integrative transcriptomic and metabolomic analysis under high light in order to unveil key mechanisms involved in the early steps of plants terrestralization. We found a fast chloroplast retrograde signaling possibly mediated by reactive oxygen species and the inositol polyphosphate 1-phosphatase (SAL1) and 3'-phosphoadenosine-5'-phosphate (PAP) pathways inducing gene expression and accumulation of specific metabolites. Systems used by both Chlorophyta and Embryophyta were activated such as the xanthophyll cycle with an accumulation of zeaxanthin and protein folding and repair mechanisms constituted by NADPH-dependent thioredoxin reductases, thioredoxin-disulfide reductases, and peroxiredoxins. Similarly, cyclic electron flow, specifically the pathway dependent on proton gradient regulation 5, was strongly activated under high light. We detected a simultaneous co-activation of the non-photochemical quenching mechanisms based on LHC-like stress related (LHCSR) protein and the photosystem II subunit S that are specific to Chlorophyta and Embryophyta, respectively. Exclusive Embryophyta systems for the synthesis, sensing, and response to the phytohormone auxin were also activated under high light in K. nitens leading to an increase in auxin content with the concomitant accumulation of amino acids such as tryptophan, histidine, and phenylalanine.
Collapse
Affiliation(s)
- Emma Serrano-Pérez
- Microalgae Systems Biology and Biotechnology Research Group, Institute for Plant Biochemistry and Photosynthesis, Universidad de Sevilla – Consejo Superior de Investigaciones Científicas, Seville, Spain
- Department of Computer Science and Artificial Intelligence, Universidad de Sevilla, Seville, Spain
| | - Ana B. Romero-Losada
- Microalgae Systems Biology and Biotechnology Research Group, Institute for Plant Biochemistry and Photosynthesis, Universidad de Sevilla – Consejo Superior de Investigaciones Científicas, Seville, Spain
- Department of Computer Science and Artificial Intelligence, Universidad de Sevilla, Seville, Spain
| | - María Morales-Pineda
- Microalgae Systems Biology and Biotechnology Research Group, Institute for Plant Biochemistry and Photosynthesis, Universidad de Sevilla – Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - M. Elena García-Gómez
- Microalgae Systems Biology and Biotechnology Research Group, Institute for Plant Biochemistry and Photosynthesis, Universidad de Sevilla – Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Inmaculada Couso
- Microalgae Systems Biology and Biotechnology Research Group, Institute for Plant Biochemistry and Photosynthesis, Universidad de Sevilla – Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Mercedes García-González
- Microalgae Systems Biology and Biotechnology Research Group, Institute for Plant Biochemistry and Photosynthesis, Universidad de Sevilla – Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Francisco J. Romero-Campero
- Microalgae Systems Biology and Biotechnology Research Group, Institute for Plant Biochemistry and Photosynthesis, Universidad de Sevilla – Consejo Superior de Investigaciones Científicas, Seville, Spain
- Department of Computer Science and Artificial Intelligence, Universidad de Sevilla, Seville, Spain
- *Correspondence: Francisco J. Romero-Campero,
| |
Collapse
|
19
|
Ptushenko VV, Bondarenko GN, Vinogradova EN, Glagoleva ES, Karpova OV, Ptushenko OS, Solovchenko AE, Trubitsin BV, Chivkunova OB, Shibzukhova KA, Shcherbakov PN. The Effect of Chilling on the Photosynthetic Apparatus of Microalga Lobosphaera incisa IPPAS C-2047. BIOCHEMISTRY. BIOKHIMIIA 2021; 86:1590-1598. [PMID: 34937538 DOI: 10.1134/s0006297921120087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Photosynthetic organisms have developed a set of mechanisms aimed at preventing photo-oxidative reactions in the photosynthetic apparatus (PSA) initiated by excessively absorbed light energy. Along with high irradiance, other stressors, e.g., chilling temperatures, can lead to the absorption of the excess of light energy and hence to photo-oxidative stress. Here, we studied induction of photoprotective mechanisms in response to chilling (0°C) at a low irradiance (50 µmol PAR photons m-2·s-1) in the cells of microalga Lobosphaera incisa IPPAS C-2047. After 4 days of incubation at a low temperature, L. incisa IPPAS C-2047 cells showed a notable decrease in the photochemical activity of photosystem II (PSII) and in the efficiency of photosynthetic electron transport, as well as a significant increase in the thermal dissipation of the absorbed light energy in the light-harvesting antenna. In contrast, most conventional markers of PSA acclimation to excess light energy [total chlorophyll and carotenoid content; violaxanthin cycle pigment content and de-epoxidation state; photosynthetic antenna, PSII, and photosystem I (PSI) ratio] remained virtually unchanged. The content of major unsaturated fatty acids also remained almost unaffected, except for arachidonic acid (increased by 40%) recently assumed to activate violaxanthin de-epoxidase by adjusting its lipid microenvironment. Significant changes (4-7-fold increase) were observed in the expression of the gene encoding protective protein LhcSR. Pre-conditioning at 5°C prior to the acclimation to 0°C augmented the PSA photochemical activity. Our data show that the mid-term (4-d) acclimation of L. incisa IPPAS C-2047 to a chilling temperature at a low irradiance triggers the PSA response resembling, in part, the response to high light but relying mostly on the LhcSR protein-dependent quenching of excitation in the photosynthetic antenna.
Collapse
Affiliation(s)
- Vasily V Ptushenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia. .,Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, 119334, Russia
| | | | - Elizaveta N Vinogradova
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.,National Research Center "Kurchatov Institute", 123182 Moscow Russia
| | - Elena S Glagoleva
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Olga V Karpova
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Oxana S Ptushenko
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | | | - Boris V Trubitsin
- Faculty of Physics, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Olga B Chivkunova
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | | | - Pavel N Shcherbakov
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| |
Collapse
|
20
|
Buck JM, Kroth PG, Lepetit B. Identification of sequence motifs in Lhcx proteins that confer qE-based photoprotection in the diatom Phaeodactylum tricornutum. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 108:1721-1734. [PMID: 34651379 DOI: 10.1111/tpj.15539] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 08/11/2021] [Indexed: 05/08/2023]
Abstract
Photosynthetic organisms in nature often experience light fluctuations. While low light conditions limit the energy uptake by algae, light absorption exceeding the maximal rate of photosynthesis may go along with enhanced formation of potentially toxic reactive oxygen species. To preempt high light-induced photodamage, photosynthetic organisms evolved numerous photoprotective mechanisms. Among these, energy-dependent fluorescence quenching (qE) provides a rapid mechanism to dissipate thermally the excessively absorbed energy. Diatoms thrive in all aquatic environments and thus belong to the most important primary producers on earth. qE in diatoms is provided by a concerted action of Lhcx proteins and the xanthophyll cycle pigment diatoxanthin. While the exact Lhcx activation mechanism of diatom qE is unknown, two lumen-exposed acidic amino acids within Lhcx proteins were proposed to function as regulatory switches upon light-induced lumenal acidification. By introducing a modified Lhcx1 lacking these amino acids into a Phaeodactylum tricornutum Lhcx1-null qE knockout line, we demonstrate that qE is unaffected by these two amino acids. Based on sequence comparisons with Lhcx4, being incapable of providing qE, we perform domain swap experiments of Lhcx4 with Lhcx1 and identify two peptide motifs involved in conferring qE. Within one of these motifs, we identify a tryptophan residue with a major influence on qE establishment. This tryptophan residue is located in close proximity to the diadinoxanthin/diatoxanthin-binding site based on the recently revealed diatom Lhc crystal structure. Our findings provide a structural explanation for the intimate link of Lhcx and diatoxanthin in providing qE in diatoms.
Collapse
Affiliation(s)
- Jochen M Buck
- Plant Ecophysiology, Department of Biology, University of Konstanz, Konstanz, 78457, Germany
| | - Peter G Kroth
- Plant Ecophysiology, Department of Biology, University of Konstanz, Konstanz, 78457, Germany
| | - Bernard Lepetit
- Plant Ecophysiology, Department of Biology, University of Konstanz, Konstanz, 78457, Germany
| |
Collapse
|
21
|
Aso M, Matsumae R, Tanaka A, Tanaka R, Takabayashi A. Unique Peripheral Antennas in the Photosystems of the Streptophyte Alga Mesostigma viride. PLANT & CELL PHYSIOLOGY 2021; 62:436-446. [PMID: 33416834 DOI: 10.1093/pcp/pcaa172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 12/19/2020] [Indexed: 06/12/2023]
Abstract
Land plants evolved from a single group of streptophyte algae. One of the key factors needed for adaptation to a land environment is the modification in the peripheral antenna systems of photosystems (PSs). Here, the PSs of Mesostigma viride, one of the earliest-branching streptophyte algae, were analyzed to gain insight into their evolution. Isoform sequencing and phylogenetic analyses of light-harvesting complexes (LHCs) revealed that M. viride possesses three algae-specific LHCs, including algae-type LHCA2, LHCA9 and LHCP, while the streptophyte-specific LHCB6 was not identified. These data suggest that the acquisition of LHCB6 and the loss of algae-type LHCs occurred after the M. viride lineage branched off from other streptophytes. Clear-native (CN)-polyacrylamide gel electrophoresis (PAGE) resolved the photosynthetic complexes, including the PSI-PSII megacomplex, PSII-LHCII, two PSI-LHCI-LHCIIs, PSI-LHCI and the LHCII trimer. Results indicated that the higher-molecular weight PSI-LHCI-LHCII likely had more LHCII than the lower-molecular weight one, a unique feature of M. viride PSs. CN-PAGE coupled with mass spectrometry strongly suggested that the LHCP was bound to PSII-LHCII, while the algae-type LHCA2 and LHCA9 were bound to PSI-LHCI, both of which are different from those in land plants. Results of the present study strongly suggest that M. viride PSs possess unique features that were inherited from a common ancestor of streptophyte and chlorophyte algae.
Collapse
Affiliation(s)
- Michiki Aso
- Institute of Low Temperature Science, Hokkaido University, N19 W8 Kita-ku, Sapporo, 060-0819 Japan
| | - Renon Matsumae
- Institute of Low Temperature Science, Hokkaido University, 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
| | - Ryouichi Tanaka
- Institute of Low Temperature Science, Hokkaido University, N19 W8 Kita-ku, Sapporo, 060-0819 Japan
| | - Atsushi Takabayashi
- Institute of Low Temperature Science, Hokkaido University, N19 W8 Kita-ku, Sapporo, 060-0819 Japan
| |
Collapse
|
22
|
Markham KK, Greenham K. Abiotic stress through time. THE NEW PHYTOLOGIST 2021; 231:40-46. [PMID: 33780004 DOI: 10.1111/nph.17367] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 03/12/2021] [Indexed: 06/12/2023]
Abstract
Throughout plant evolution the circadian clock has expanded into a complex signaling network, coordinating physiological and metabolic processes with the environment. Early land plants faced new environmental pressures that required energy-demanding stress responses. Integrating abiotic stress response into the circadian system provides control over daily energy expenditure. Here, we describe the evolution of the circadian clock in plants and the limited, yet compelling, evidence for conserved regulation of abiotic stress. The need to introduce abiotic stress tolerance into current crops has expanded research into wild accessions and revealed extensive variation in circadian clock parameters across monocot and eudicot species. We argue that research into the ancestral links between the clock and abiotic stress will benefit crop improvement efforts.
Collapse
Affiliation(s)
- Kathleen K Markham
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Kathleen Greenham
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN, 55108, USA
| |
Collapse
|
23
|
Levin G, Kulikovsky S, Liveanu V, Eichenbaum B, Meir A, Isaacson T, Tadmor Y, Adir N, Schuster G. The desert green algae Chlorella ohadii thrives at excessively high light intensities by exceptionally enhancing the mechanisms that protect photosynthesis from photoinhibition. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:1260-1277. [PMID: 33725388 DOI: 10.1111/tpj.15232] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 03/09/2021] [Accepted: 03/11/2021] [Indexed: 06/12/2023]
Abstract
Although light is the driving force of photosynthesis, excessive light can be harmful. One of the main processes that limits photosynthesis is photoinhibition, the process of light-induced photodamage. When the absorbed light exceeds the amount that is dissipated by photosynthetic electron flow and other processes, damaging radicals are formed that mostly inactivate photosystem II (PSII). Damaged PSII must be replaced by a newly repaired complex in order to preserve full photosynthetic activity. Chlorella ohadii is a green microalga, isolated from biological desert soil crusts, that thrives under extreme high light and is highly resistant to photoinhibition. Therefore, C. ohadii is an ideal model for studying the molecular mechanisms underlying protection against photoinhibition. Comparison of the thylakoids of C. ohadii cells that were grown under low light versus extreme high light intensities found that the alga employs all three known photoinhibition protection mechanisms: (i) massive reduction of the PSII antenna size; (ii) accumulation of protective carotenoids; and (iii) very rapid repair of photodamaged reaction center proteins. This work elucidated the molecular mechanisms of photoinhibition resistance in one of the most light-tolerant photosynthetic organisms, and shows how photoinhibition protection mechanisms evolved to marginal conditions, enabling photosynthesis-dependent life in severe habitats.
Collapse
Affiliation(s)
- Guy Levin
- Faculty of Biology, Technion, Haifa, 32000, Israel
| | | | | | | | - Ayala Meir
- Department of Vegetable Research, Agricultural Research Organization, Newe Ya'ar Research Center, Ramat Yishay, Israel
| | - Tal Isaacson
- Department of Vegetable Research, Agricultural Research Organization, Newe Ya'ar Research Center, Ramat Yishay, Israel
| | - Yaakov Tadmor
- Department of Vegetable Research, Agricultural Research Organization, Newe Ya'ar Research Center, Ramat Yishay, Israel
| | - Noam Adir
- Grand Technion Energy Program, Technion, Haifa, 32000, Israel
- Schulich Faculty of Chemistry, Technion, Haifa, 32000, Israel
| | - Gadi Schuster
- Faculty of Biology, Technion, Haifa, 32000, Israel
- Grand Technion Energy Program, Technion, Haifa, 32000, Israel
| |
Collapse
|
24
|
Commault AS, Kuzhiumparambil U, Herdean A, Fabris M, Jaramillo-Madrid AC, Abbriano RM, Ralph PJ, Pernice M. Methyl Jasmonate and Methyl-β-Cyclodextrin Individually Boost Triterpenoid Biosynthesis in Chlamydomonas Reinhardtii UVM4. Pharmaceuticals (Basel) 2021; 14:125. [PMID: 33562714 PMCID: PMC7915139 DOI: 10.3390/ph14020125] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/01/2021] [Accepted: 02/01/2021] [Indexed: 01/01/2023] Open
Abstract
The commercialisation of valuable plant triterpenoids faces major challenges, including low abundance in natural hosts and costly downstream purification procedures. Endeavours to produce these compounds at industrial scale using microbial systems are gaining attention. Here, we report on a strategy to enrich the biomass of the biotechnologically-relevant Chlamydomonas reinhardtii strain UVM4 with valuable triterpenes, such as squalene and (S)-2,3-epoxysqualene. C. reinhardtii UVM4 was subjected to the elicitor compounds methyl jasmonate (MeJA) and methyl-β-cyclodextrine (MβCD) to increase triterpene yields. MeJA treatment triggered oxidative stress, arrested growth, and altered the photosynthetic activity of the cells, while increasing squalene, (S)-2,3-epoxysqualene, and cycloartenol contents. Applying MβCD to cultures of C. reinhardtii lead to the sequestration of the two main sterols (ergosterol and 7-dehydroporiferasterol) into the growth medium and the intracellular accumulation of the intermediate cycloartenol, without compromising cell growth. When MβCD was applied in combination with MeJA, it counteracted the negative effects of MeJA on cell growth and physiology, but no synergistic effect on triterpene yield was observed. Together, our findings provide strategies for the triterpene enrichment of microalgal biomass and medium.
Collapse
Affiliation(s)
- Audrey S. Commault
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia; (U.K.); (A.H.); (M.F.); (A.C.J.-M.); (R.M.A.); (P.J.R.); (M.P.)
| | - Unnikrishnan Kuzhiumparambil
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia; (U.K.); (A.H.); (M.F.); (A.C.J.-M.); (R.M.A.); (P.J.R.); (M.P.)
| | - Andrei Herdean
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia; (U.K.); (A.H.); (M.F.); (A.C.J.-M.); (R.M.A.); (P.J.R.); (M.P.)
| | - Michele Fabris
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia; (U.K.); (A.H.); (M.F.); (A.C.J.-M.); (R.M.A.); (P.J.R.); (M.P.)
- Synthetic Biology Future Science Platform, CSIRO, Brisbane, QLD 4001, Australia
| | - Ana Cristina Jaramillo-Madrid
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia; (U.K.); (A.H.); (M.F.); (A.C.J.-M.); (R.M.A.); (P.J.R.); (M.P.)
| | - Raffaela M. Abbriano
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia; (U.K.); (A.H.); (M.F.); (A.C.J.-M.); (R.M.A.); (P.J.R.); (M.P.)
| | - Peter J. Ralph
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia; (U.K.); (A.H.); (M.F.); (A.C.J.-M.); (R.M.A.); (P.J.R.); (M.P.)
| | - Mathieu Pernice
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia; (U.K.); (A.H.); (M.F.); (A.C.J.-M.); (R.M.A.); (P.J.R.); (M.P.)
| |
Collapse
|
25
|
Coenzyme Q 10 Analogues: Benefits and Challenges for Therapeutics. Antioxidants (Basel) 2021; 10:antiox10020236. [PMID: 33557229 PMCID: PMC7913973 DOI: 10.3390/antiox10020236] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/26/2021] [Accepted: 01/29/2021] [Indexed: 01/31/2023] Open
Abstract
Coenzyme Q10 (CoQ10 or ubiquinone) is a mobile proton and electron carrier of the mitochondrial respiratory chain with antioxidant properties widely used as an antiaging health supplement and to relieve the symptoms of many pathological conditions associated with mitochondrial dysfunction. Even though the hegemony of CoQ10 in the context of antioxidant-based treatments is undeniable, the future primacy of this quinone is hindered by the promising features of its numerous analogues. Despite the unimpeachable performance of CoQ10 therapies, problems associated with their administration and intraorganismal delivery has led clinicians and scientists to search for alternative derivative molecules. Over the past few years, a wide variety of CoQ10 analogues with improved properties have been developed. These analogues conserve the antioxidant features of CoQ10 but present upgraded characteristics such as water solubility or enhanced mitochondrial accumulation. Moreover, recent studies have proven that some of these analogues might even outperform CoQ10 in the treatment of certain specific diseases. The aim of this review is to provide detailed information about these Coenzyme Q10 analogues, as well as their functionality and medical applications.
Collapse
|
26
|
Bhuiyan R, van Iersel MW. Only Extreme Fluctuations in Light Levels Reduce Lettuce Growth Under Sole Source Lighting. FRONTIERS IN PLANT SCIENCE 2021; 12:619973. [PMID: 33584773 PMCID: PMC7875872 DOI: 10.3389/fpls.2021.619973] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 01/06/2021] [Indexed: 05/02/2023]
Abstract
The cost of providing lighting in greenhouses and plant factories can be high. In the case of variable electricity prices, providing most of the light when electricity prices are low can reduce costs. However, it is not clear how plants respond to the resulting fluctuating light levels. We hypothesized that plants that receive a constant photosynthetic photon flux density (PPFD) will produce more biomass than those grown under fluctuating light levels. To understand potential growth reductions caused by fluctuating light levels, we quantified the effects of fluctuating PPFD on the photosynthetic physiology, morphology, and growth of 'Little Gem' and 'Green Salad Bowl' lettuce. Plants were grown in a growth chamber with dimmable white LED bars, alternating between high and low PPFDs every 15 min. The PPFDs were ∼400/0, 360/40, 320/80, 280/120, 240/160, and 200/200 μmol⋅m-2⋅s-1, with a photoperiod of 16 h and a DLI of ∼11.5 mol⋅m-2⋅day-1 in all treatments. CO2 was ∼800 μmol⋅mol-1. Plants in the 400/0 μmol⋅m-2⋅s-1 treatment had ∼69% lower An,30 (net assimilation averaged over 15 min at high and 15 min at low PPFD) than plants grown at a PPFD of 320/80 μmol⋅m-2⋅s-1 (or treatments with smaller PPFD fluctuations). The low An,30 in the 400/0, and to a lesser extent the 360/40 μmol⋅m-2⋅s-1 treatment was caused by low net assimilation at 360 and 400 μmol⋅m-2⋅s-1. Plants grown at 400/0 μmol⋅m-2⋅s-1 also had fewer leaves and lower chlorophyll content compared to those in other treatments. The four treatments with the smallest PPFD fluctuations produced plants with similar numbers of leaves, chlorophyll content, specific leaf area (SLA), dry mass, and leaf area. Chlorophyll content, An,30, and dry mass were positively correlated with each other. Our results show that lettuce tolerates a wide range of fluctuating PPFD without negative effects on growth and development. However, when fluctuations in PPFD are extreme (400/0 or 360/40 μmol⋅m-2⋅s-1), chlorophyll levels and An,30 are low, which can explain the low poor growth in these treatments. The ability of lettuce to tolerate a wide range of fluctuating light levels suggests that PPFD can be adjusted in response to variable electricity pricing.
Collapse
|
27
|
Estimation of Leaf Chlorophyll a, b and Carotenoid Contents and Their Ratios Using Hyperspectral Reflectance. REMOTE SENSING 2020. [DOI: 10.3390/rs12193265] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Japanese horseradish (wasabi) grows in very specific conditions, and recent environmental climate changes have damaged wasabi production. In addition, the optimal culture methods are not well known, and it is becoming increasingly difficult for incipient farmers to cultivate it. Chlorophyll a, b and carotenoid contents, as well as their allocation, could be an adequate indicator in evaluating its production and environmental stress; thus, developing an in situ method to monitor photosynthetic pigments based on reflectance could be useful for agricultural management. Besides original reflectance (OR), five pre-processing techniques, namely, first derivative reflectance (FDR), continuum-removed (CR), de-trending (DT), multiplicative scatter correction (MSC), and standard normal variate transformation (SNV), were compared to assess the accuracy of the estimation. Furthermore, five machine learning algorithms—random forest (RF), support vector machine (SVM), kernel-based extreme learning machine (KELM), Cubist, and Stochastic Gradient Boosting (SGB)—were considered. To classify the samples under different pH or sulphur ion concentration conditions, the end of the red edge bands was effective for OR, FDR, DT, MSC, and SNV, while a green-peak band was effective for CR. Overall, KELM and Cubist showed high performance and incorporating pre-processing techniques was effective for obtaining estimated values with high accuracy. The best combinations were found to be DT–KELM for chl a (RPD = 1.511–5.17, RMSE = 1.23–3.62 μg cm−2) and chl a:b (RPD = 0.73–3.17, RMSE = 0.13–0.60); CR–KELM for chl b (RPD = 1.92–5.06, RMSE = 0.41–1.03 μg cm−2) and chl a:car (RPD = 1.31–3.23, RMSE = 0.26–0.50); SNV–Cubist for car (RPD = 1.63–3.32, RMSE = 0.31–1.89 μg cm−2); and DT–Cubist for chl:car (RPD = 1.53–3.96, RMSE = 0.27–0.74).
Collapse
|
28
|
Assembly of eukaryotic photosystem II with diverse light-harvesting antennas. Curr Opin Struct Biol 2020; 63:49-57. [PMID: 32389895 DOI: 10.1016/j.sbi.2020.03.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 03/07/2020] [Accepted: 03/08/2020] [Indexed: 11/21/2022]
Abstract
Photosystem II (PSII) catalyzes the light-driven oxygen-evolving reaction via its catalytic core and peripheral light-harvesting antennas. Oxyphototrophs have evolved diverse antenna systems, enabling them to adapt to different habitats. Recently, high-resolution structures of PSII-antenna supercomplexes from the green lineage (higher plants and green algae) and the red lineage (diatoms) were solved. The antenna complexes from the two lineages share similar protein folding, but differ in terms of the oligomeric states, pigment composition, and assembly patterns with the core. These differences result in distinct pigment-protein networks in PSII from different organisms. We herein summarize the similarities and differences in these structures and outline the molecular basis of the assembly, energy transfer, and regulation of the eukaryotic PSII-antenna supercomplexes.
Collapse
|