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Sun M, Shen Y. Integrating the multiple functions of CHLH into chloroplast-derived signaling fundamental to plant development and adaptation as well as fruit ripening. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 338:111892. [PMID: 37821024 DOI: 10.1016/j.plantsci.2023.111892] [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: 04/12/2023] [Revised: 10/01/2023] [Accepted: 10/06/2023] [Indexed: 10/13/2023]
Abstract
Chlorophyll (Chl)-mediated oxygenic photosynthesis sustains life on Earth. Greening leaves play fundamental roles in plant growth and crop yield, correlating with the idea that more Chls lead to better adaptation. However, they face significant challenges from various unfavorable environments. Chl biosynthesis hinges on the first committed step, which involves inserting Mg2+ into protoporphyrin. This step is facilitated by the H subunit of magnesium chelatase (CHLH) and features a conserved mechanism from cyanobacteria to plants. For better adaptation to fluctuating land environments, especially drought, CHLH evolves multiple biological functions, including Chl biosynthesis, retrograde signaling, and abscisic acid (ABA) responses. Additionally, it integrates into various chloroplast-derived signaling pathways, encompassing both retrograde signaling and hormonal signaling. The former comprises ROS (reactive oxygen species), heme, GUN (genomes uncoupled), MEcPP (methylerythritol cyclodiphosphate), β-CC (β-cyclocitral), and PAP (3'-phosphoadenosine-5'-phosphate). The latter involves phytohormones like ABA, ethylene, auxin, cytokinin, gibberellin, strigolactone, brassinolide, salicylic acid, and jasmonic acid. Together, these elements create a coordinated regulatory network tailored to plant development and adaptation. An intriguing example is how drought-mediated improvement of fruit quality provides insights into chloroplast-derived signaling, aiding the shift from vegetative to reproductive growth. In this context, we explore the integration of CHLH's multifaceted roles into chloroplast-derived signaling, which lays the foundation for plant development and adaptation, as well as fruit ripening and quality. In the future, manipulating chloroplast-derived signaling may offer a promising avenue to enhance crop yield and quality through the homeostasis, function, and regulation of Chls.
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Affiliation(s)
- Mimi Sun
- College of Horticulture, China Agricultural University, Beijing 100193, China; College of Plant Science and Technology, Beijing University of Agriculture, 7 Beinong Road, Changping District, Beijing 102206, China
| | - Yuanyue Shen
- College of Plant Science and Technology, Beijing University of Agriculture, 7 Beinong Road, Changping District, Beijing 102206, China.
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Ishikawa K, Xie X, Osaki Y, Miyawaki A, Numata K, Kodama Y. Bilirubin is produced nonenzymatically in plants to maintain chloroplast redox status. SCIENCE ADVANCES 2023; 9:eadh4787. [PMID: 37285441 DOI: 10.1126/sciadv.adh4787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 05/01/2023] [Indexed: 06/09/2023]
Abstract
Bilirubin, a potent antioxidant, is a product of heme catabolism in heterotrophs. Heterotrophs mitigate oxidative stress resulting from free heme by catabolism into bilirubin via biliverdin. Although plants also convert heme to biliverdin, they are generally thought to be incapable of producing bilirubin because they lack biliverdin reductase, the enzyme responsible for bilirubin biosynthesis in heterotrophs. Here, we demonstrate that bilirubin is produced in plant chloroplasts. Live-cell imaging using the bilirubin-dependent fluorescent protein UnaG revealed that bilirubin accumulated in chloroplasts. In vitro, bilirubin was produced nonenzymatically through a reaction between biliverdin and reduced form of nicotinamide adenine dinucleotide phosphate at concentrations comparable to those in chloroplasts. In addition, increased bilirubin production led to lower reactive oxygen species levels in chloroplasts. Our data refute the generally accepted pathway of heme degradation in plants and suggest that bilirubin contributes to the maintenance of redox status in chloroplasts.
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Affiliation(s)
- Kazuya Ishikawa
- Center for Bioscience Research and Education, Utsunomiya University, Tochigi 321-8505, Japan
- Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama 700-8530, Japan
| | - Xiaonan Xie
- Center for Bioscience Research and Education, Utsunomiya University, Tochigi 321-8505, Japan
| | - Yasuhide Osaki
- Center for Bioscience Research and Education, Utsunomiya University, Tochigi 321-8505, Japan
| | - Atsushi Miyawaki
- Laboratory for Cell Function Dynamics, RIKEN Center for Brain Science, Saitama 351-0198, Japan
- Biotechnological Optics Research Team, RIKEN Center for Advanced Photonics; Saitama, 351-0198, Japan
| | - Keiji Numata
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University; Kyoto, 615-8246, Japan
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, Saitama 351-0198, Japan
| | - Yutaka Kodama
- Center for Bioscience Research and Education, Utsunomiya University, Tochigi 321-8505, Japan
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, Saitama 351-0198, Japan
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Jin HL, Duan S, Zhang P, Yang Z, Zeng Y, Chen Z, Hong L, Li M, Luo L, Chang Z, Hu J, Wang HB. Dual roles for CND1 in maintenance of nuclear and chloroplast genome stability in plants. Cell Rep 2023; 42:112268. [PMID: 36933214 DOI: 10.1016/j.celrep.2023.112268] [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: 12/23/2021] [Revised: 12/19/2022] [Accepted: 02/28/2023] [Indexed: 03/19/2023] Open
Abstract
The coordination of chloroplast and nuclear genome status is critical for plant cell function. Here, we report that Arabidopsis CHLOROPLAST AND NUCLEUS DUAL-LOCALIZED PROTEIN 1 (CND1) maintains genome stability in the chloroplast and the nucleus. CND1 localizes to both compartments, and complete loss of CND1 results in embryo lethality. Partial loss of CND1 disturbs nuclear cell-cycle progression and photosynthetic activity. CND1 binds to nuclear pre-replication complexes and DNA replication origins and regulates nuclear genome stability. In chloroplasts, CND1 interacts with and facilitates binding of the regulator of chloroplast genome stability WHY1 to chloroplast DNA. The defects in nuclear cell-cycle progression and photosynthesis of cnd1 mutants are respectively rescued by compartment-restricted CND1 localization. Light promotes the association of CND1 with HSP90 and its import into chloroplasts. This study provides a paradigm of the convergence of genome status across organelles to coordinately regulate cell cycle to control plant growth and development.
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Affiliation(s)
- Hong-Lei Jin
- Institute of Medical Plant Physiology and Ecology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China; Guangzhou Key Laboratory of Chinese Medicine Research on Prevention and Treatment of Osteoporosis, The Third Affiliated Hospital of Guangzhou University of Chinese Medicine, No. 263, Longxi Avenue, Guangzhou, China.
| | - Sujuan Duan
- Institute of Medical Plant Physiology and Ecology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China
| | - Pengxiang Zhang
- Institute of Medical Plant Physiology and Ecology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China
| | - Ziyue Yang
- Institute of Medical Plant Physiology and Ecology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China
| | - Yunping Zeng
- Institute of Medical Plant Physiology and Ecology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China
| | - Ziqi Chen
- Institute of Medical Plant Physiology and Ecology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China
| | - Liu Hong
- Institute of Medical Plant Physiology and Ecology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China
| | - Mengshu Li
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Lujun Luo
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Zhenyi Chang
- Institute of Medical Plant Physiology and Ecology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China
| | - Jiliang Hu
- Institute of Medical Plant Physiology and Ecology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China
| | - Hong-Bin Wang
- Institute of Medical Plant Physiology and Ecology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China; Key Laboratory of Chinese Medicinal Resource from Lingnan (Guangzhou University of Chinese Medicine), Ministry of Education, Guangzhou, China; State Key Laboratory of Dampness Syndrome of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China.
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4
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Akagi C, Kurihara Y, Makita Y, Kawauchi M, Tsuge T, Aoyama T, Matsui M. Translational activation of ribosome-related genes at initial photoreception is dependent on signals derived from both the nucleus and the chloroplasts in Arabidopsis thaliana. JOURNAL OF PLANT RESEARCH 2023; 136:227-238. [PMID: 36658292 DOI: 10.1007/s10265-022-01430-8] [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: 09/21/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Light is one of the indispensable elements that plants need in order to grow and develop. In particular, it is essential for inducing morphogenesis, such as suppression of hypocotyl elongation and cotyledon expansion, that plants undergo when they first emerge after germination. However, there is a lack of knowledge about the gene expression and, in particular, the translational levels that induce a response upon light exposure. We have investigated the translational expression of nuclear genes in Arabidopsis thaliana seedlings germinated in the dark and then exposed to blue monochromatic light. In this study, ribosome profiling analysis was performed in the blue-light-receptor mutant cry1cry2 and the light-signaling mutant hy5 to understand which signaling pathways are responsible for the changes in gene expression at the translational level after blue-light exposure. The analysis showed that the expression of certain chloroplast- and ribosome-related genes was up-regulated at the translational level in the wild type. However, in both mutants the translational up-regulation of ribosome-related genes was apparently compromised. This suggests that light signaling through photoreceptors and the HY5 transcription factor are responsible for translation of ribosome-related genes. To further understand the effect of photoreception by chloroplasts on nuclear gene expression, chloroplast function was inhibited by adding a photosynthesis inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), and a carotenoid synthesis inhibitor, norflurazon. The results show that inhibition of chloroplast function did not lead to an increase in the expression of ribosome-related genes at the translational level. These results suggest that signals from both the nucleus and chloroplasts are required to activate translation of ribosome-related genes during blue-light reception.
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Affiliation(s)
- Chika Akagi
- Synthetic Genomics Research Group, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Yukio Kurihara
- Synthetic Genomics Research Group, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902, Japan
| | - Yuko Makita
- Synthetic Genomics Research Group, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
- Faculty of Engineering, Maebashi Institute of Technology, Kamisadori 460-1, Maebashi, Gunma, 371-0816, Japan
| | - Masaharu Kawauchi
- Synthetic Genomics Research Group, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Tomohiko Tsuge
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Takashi Aoyama
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Minami Matsui
- Synthetic Genomics Research Group, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.
- Graduate School of Nanobioscience Department of Life and Environmental System Science, Yokohama City University, Yokohama, Kanagawa, 236-0027, Japan.
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Méteignier LV. Exfiltration from the chloroplast: A shuttle protein shows the way to the nucleus. THE PLANT CELL 2023; 35:634-635. [PMID: 36427254 PMCID: PMC9940861 DOI: 10.1093/plcell/koac332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 11/17/2022] [Indexed: 06/16/2023]
Affiliation(s)
- Louis-Valentin Méteignier
- Assistant Features Editor, The Plant Cell, American Society of Plant Biologists, USA
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
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Wheat Long Noncoding RNAs from Organelle and Nuclear Genomes Carry Conserved microRNA Precursors Which May Together Comprise Intricate Networks in Insect Responses. Int J Mol Sci 2023; 24:ijms24032226. [PMID: 36768565 PMCID: PMC9917100 DOI: 10.3390/ijms24032226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/10/2023] [Accepted: 01/20/2023] [Indexed: 01/24/2023] Open
Abstract
Long noncoding RNAs (lncRNAs) are a diverse class of noncoding RNAs that are typically longer than 200 nucleotides but lack coding potentials. Advances in deep sequencing technologies enabled a better exploration of this type of noncoding transcripts. The poor sequence conservation, however, complicates the identification and annotation of lncRNAs at a large scale. Wheat is among the leading food staples worldwide whose production is threatened by both biotic and abiotic stressors. Here, we identified putative lncRNAs from durum wheat varieties that differ in stem solidness, a major source of defense against wheat stem sawfly, a devastating insect pest. We also analyzed and annotated lncRNAs from two bread wheat varieties, resistant and susceptible to another destructive pest, orange wheat blossom midge, with and without infestation. Several putative lncRNAs contained potential precursor sequences and/or target regions for microRNAs, another type of regulatory noncoding RNAs, which may indicate functional networks. Interestingly, in contrast to lncRNAs themselves, microRNAs with potential precursors within the lncRNA sequences appeared to be highly conserved at the sequence and family levels. We also observed a few putative lncRNAs that have perfect to near-perfect matches to organellar genomes, supporting the recent observations that organellar genomes may contribute to the noncoding transcript pool of the cell.
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Richter AS, Nägele T, Grimm B, Kaufmann K, Schroda M, Leister D, Kleine T. Retrograde signaling in plants: A critical review focusing on the GUN pathway and beyond. PLANT COMMUNICATIONS 2023; 4:100511. [PMID: 36575799 PMCID: PMC9860301 DOI: 10.1016/j.xplc.2022.100511] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 12/05/2022] [Accepted: 12/22/2022] [Indexed: 06/01/2023]
Abstract
Plastids communicate their developmental and physiological status to the nucleus via retrograde signaling, allowing nuclear gene expression to be adjusted appropriately. Signaling during plastid biogenesis and responses of mature chloroplasts to environmental changes are designated "biogenic" and "operational" controls, respectively. A prominent example of the investigation of biogenic signaling is the screen for gun (genomes uncoupled) mutants. Although the first five gun mutants were identified 30 years ago, the functions of GUN proteins in retrograde signaling remain controversial, and that of GUN1 is hotly disputed. Here, we provide background information and critically discuss recently proposed concepts that address GUN-related signaling and some novel gun mutants. Moreover, considering heme as a candidate in retrograde signaling, we revisit the spatial organization of heme biosynthesis and export from plastids. Although this review focuses on GUN pathways, we also highlight recent progress in the identification and elucidation of chloroplast-derived signals that regulate the acclimation response in green algae and plants. Here, stress-induced accumulation of unfolded/misassembled chloroplast proteins evokes a chloroplast-specific unfolded protein response, which leads to changes in the expression levels of nucleus-encoded chaperones and proteases to restore plastid protein homeostasis. We also address the importance of chloroplast-derived signals for activation of flavonoid biosynthesis leading to production of anthocyanins during stress acclimation through sucrose non-fermenting 1-related protein kinase 1. Finally, a framework for identification and quantification of intercompartmental signaling cascades at the proteomic and metabolomic levels is provided, and we discuss future directions of dissection of organelle-nucleus communication.
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Affiliation(s)
- Andreas S Richter
- Physiology of Plant Metabolism, Institute for Biosciences, University of Rostock, Albert-Einstein-Str. 3, 18059 Rostock, Germany
| | - Thomas Nägele
- Plant Evolutionary Cell Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Bernhard Grimm
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, Philippstr. 13, 10115 Berlin, Germany
| | - Kerstin Kaufmann
- Plant Cell and Molecular Biology, Institute of Biology, Humboldt-Universität zu Berlin, Philippstr. 13, 10115 Berlin, Germany
| | - Michael Schroda
- Molecular Biotechnology and Systems Biology, TU Kaiserslautern, Kaiserslautern, Germany
| | - Dario Leister
- Plant Molecular Biology (Botany), Faculty of Biology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Tatjana Kleine
- Plant Molecular Biology (Botany), Faculty of Biology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany.
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Ardelean IV, Bălăcescu L, Sicora O, Bălăcescu O, Mladin L, Haș V, Miclăuș M. Maize cytolines as models to study the impact of different cytoplasms on gene expression under heat stress conditions. BMC PLANT BIOLOGY 2023; 23:4. [PMID: 36588161 PMCID: PMC9806912 DOI: 10.1186/s12870-022-04023-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 12/22/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND Crops are under constant pressure due to global warming, which unfolds at a much faster pace than their ability to adapt through evolution. Agronomic traits are linked to cytoplasmic-nuclear genome interactions. It thus becomes important to understand the influence exerted by the organelles on gene expression under heat stress conditions and profit from the available genetic diversity. Maize (Zea mays) cytolines allow us to investigate how the gene expression changes under heat stress conditions in three different cytoplasmic environments, but each having the same nucleus. Analyzing retrograde signaling in such an experimental set-up has never been done before. Here, we quantified the response of three cytolines to heat stress as differentially expressed genes (DEGs), and studied gene expression patterns in the context of existing polymorphism in their organellar genomes. RESULTS Our study unveils a plethora of new genes and GO terms that are differentially expressed or enriched, respectively, in response to heat stress. We report 19,600 DEGs as responding to heat stress (out of 30,331 analyzed), which significantly enrich 164 GO biological processes, 30 GO molecular functions, and 83 GO cell components. Our approach allowed for the discovery of a significant number of DEGs and GO terms that are not common in the three cytolines and could therefore be linked to retrograde signaling. Filtering for DEGs with a fold regulation > 2 (absolute values) that are exclusive to just one of the cytolines, we find a total of 391 up- and down-DEGs. Similarly, there are 19 GO terms with a fold enrichment > 2 that are cytoline-specific. Using GBS data we report contrasting differences in the number of DEGs and GO terms in each cytoline, which correlate with the genetic distances between the mitochondrial genomes (but not chloroplast) and the original nuclei of the cytolines, respectively. CONCLUSIONS The experimental design used here adds a new facet to the paradigm used to explain how gene expression changes in response to heat stress, capturing the influence exerted by different organelles upon one nucleus rather than investigating the response of several nuclei in their innate cytoplasmic environments.
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Affiliation(s)
- Ioana V Ardelean
- Biological Research Center, "Babeș-Bolyai" University, Jibou, Romania
- NIRDBS, Institute of Biological Research, Cluj-Napoca, Romania
| | | | - Oana Sicora
- Biological Research Center, "Babeș-Bolyai" University, Jibou, Romania
| | - Ovidiu Bălăcescu
- The Oncology Institute "Prof Dr Ion Chiricuta", Cluj-Napoca, Romania
| | - Lia Mladin
- Biological Research Center, "Babeș-Bolyai" University, Jibou, Romania
| | - Voichița Haș
- Agricultural Research and Development Station, Turda, Romania
| | - Mihai Miclăuș
- NIRDBS, Institute of Biological Research, Cluj-Napoca, Romania.
- STAR-UBB, "Babeș-Bolyai" University, Cluj-Napoca, Romania.
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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.
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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,
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