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Zirngibl ME, Araguirang GE, Kitashova A, Jahnke K, Rolka T, Kühn C, Nägele T, Richter AS. Triose phosphate export from chloroplasts and cellular sugar content regulate anthocyanin biosynthesis during high light acclimation. Plant Commun 2023; 4:100423. [PMID: 35962545 PMCID: PMC9860169 DOI: 10.1016/j.xplc.2022.100423] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 07/22/2022] [Accepted: 08/09/2022] [Indexed: 05/07/2023]
Abstract
Plants have evolved multiple strategies to cope with rapid changes in the environment. During high light (HL) acclimation, the biosynthesis of photoprotective flavonoids, such as anthocyanins, is induced. However, the exact nature of the signal and downstream factors for HL induction of flavonoid biosynthesis (FB) is still under debate. Here, we show that carbon fixation in chloroplasts, subsequent export of photosynthates by triose phosphate/phosphate translocator (TPT), and rapid increase in cellular sugar content permit the transcriptional and metabolic activation of anthocyanin biosynthesis during HL acclimation. In combination with genetic and physiological analysis, targeted and whole-transcriptome gene expression studies suggest that reactive oxygen species and phytohormones play only a minor role in rapid HL induction of the anthocyanin branch of FB. In addition to transcripts of FB, sugar-responsive genes showed delayed repression or induction in tpt-2 during HL treatment, and a significant overlap with transcripts regulated by SNF1-related protein kinase 1 (SnRK1) was observed, including a central transcription factor of FB. Analysis of mutants with increased and repressed SnRK1 activity suggests that sugar-induced inactivation of SnRK1 is required for HL-mediated activation of anthocyanin biosynthesis. Our study emphasizes the central role of chloroplasts as sensors for environmental changes as well as the vital function of sugar signaling in plant acclimation.
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Affiliation(s)
- Max-Emanuel Zirngibl
- Humboldt-Universität zu Berlin, Institute of Biology, Physiology of Plant Cell Organelles, Philippstrasse 13, 10115 Berlin, Germany
| | - Galileo Estopare Araguirang
- University of Rostock, Institute for Biosciences, Physiology of Plant Metabolism, Albert-Einstein-Strasse 3, 18059 Rostock, Germany; Humboldt-Universität zu Berlin, Institute of Biology, Physiology of Plant Cell Organelles, Philippstrasse 13, 10115 Berlin, Germany
| | - Anastasia Kitashova
- Ludwig-Maximilians-Universität München, Faculty of Biology, Plant Evolutionary Cell Biology, 82152 Planegg-Martinsried, Germany
| | - Kathrin Jahnke
- University of Rostock, Institute for Biosciences, Physiology of Plant Metabolism, Albert-Einstein-Strasse 3, 18059 Rostock, Germany
| | - Tobias Rolka
- Humboldt-Universität zu Berlin, Institute of Biology, Physiology of Plant Cell Organelles, Philippstrasse 13, 10115 Berlin, Germany
| | - Christine Kühn
- University of Rostock, Institute for Biosciences, Physiology of Plant Metabolism, Albert-Einstein-Strasse 3, 18059 Rostock, Germany
| | - Thomas Nägele
- Ludwig-Maximilians-Universität München, Faculty of Biology, Plant Evolutionary Cell Biology, 82152 Planegg-Martinsried, Germany
| | - Andreas S Richter
- University of Rostock, Institute for Biosciences, Physiology of Plant Metabolism, Albert-Einstein-Strasse 3, 18059 Rostock, Germany; Humboldt-Universität zu Berlin, Institute of Biology, Physiology of Plant Cell Organelles, Philippstrasse 13, 10115 Berlin, Germany.
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Araguirang GE, Richter AS. Activation of anthocyanin biosynthesis in high light - what is the initial signal? New Phytol 2022; 236:2037-2043. [PMID: 36110042 DOI: 10.1111/nph.18488] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 09/01/2022] [Indexed: 06/15/2023]
Abstract
Due to their sessile nature, plants cannot escape adverse environmental conditions and evolved mechanisms to cope with sudden environmental changes. The reaction to variations in abiotic factors, also summarized as acclimation response, affects all layers of cellular functions and involves rapid modification of enzymatic activities, the metabolome, proteome and transcriptome on different timescales. One trait of plants acclimating to high light (HL) is the rapid transcriptional activation of the flavonoid biosynthesis (FB) pathway resulting in the accumulation of photoprotective and antioxidative flavonoids, such as flavonols and anthocyanins, in the leaf tissue. Although enormous progress has been made in identifying enzymes and transcriptional regulators of FB by forward and reverse genetic approaches in the past, the signals and signalling pathways permitting the conditional activation of FB in HL are still debated. With this Tansley Insight, we summarize the current knowledge on the proposed signals and downstream factors involved in regulating FB and will discuss their contribution to, particularly, HL-induced accumulation of anthocyanins.
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Affiliation(s)
- Galileo Estopare Araguirang
- Physiology of Plant Metabolism, Institute for Biosciences, University of Rostock, Albert-Einstein-Strasse 3, 18059, Rostock, Germany
| | - Andreas S Richter
- Physiology of Plant Metabolism, Institute for Biosciences, University of Rostock, Albert-Einstein-Strasse 3, 18059, Rostock, Germany
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Lin YC, Araguirang GE, Ngo AH, Lin KT, Angkawijaya AE, Nakamura Y. The Four Arabidopsis Choline/Ethanolamine Kinase Isozymes Play Distinct Roles in Metabolism and Development. Plant Physiol 2020; 183:152-166. [PMID: 32205454 PMCID: PMC7210642 DOI: 10.1104/pp.19.01399] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 03/09/2020] [Indexed: 05/25/2023]
Abstract
Phosphatidylcholine and phosphatidylethanolamine are two major phospholipid classes in eukaryotes. Each biosynthesis pathway starts with the phosphorylation of choline (Cho) or ethanolamine (Etn) catalyzed by either choline or ethanolamine kinase (CEK). Arabidopsis contains four CEK isoforms, but their isozyme-specific roles in metabolism and development are poorly described. Here, we showed that these four CEKs have distinct substrate specificities in vitro. While CEK1 and CEK2 showed substrate preference for Cho over Etn, CEK3 and CEK4 had clear substrate specificity for Cho and Etn, respectively. In vivo, CEK1, CEK2, and CEK3 exhibited kinase activity for Cho but not Etn, although the latter two isoforms showed rather minor contributions to total Cho kinase activity in both shoots and roots. The knockout mutants of CEK2 and CEK3 both affected root growth, and these isoforms had nonoverlapping cell-type-specific expression patterns in the root meristematic zone. In-depth phenotype analysis, as well as chemical and genetic complementation, revealed that CEK3, a Cho-specific kinase, is involved in cell elongation during root development. Phylogenetic analysis of CEK orthologs in Brassicaceae species showed evolutionary divergence between Etn kinases and Cho kinases. Collectively, our results demonstrate the distinct roles of the four CEK isoforms in Cho/Etn metabolism and plant development.
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Affiliation(s)
- Ying-Chen Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
- Molecular and Biological Agricultural Sciences Program, Academia Sinica, Taiwan International Graduate Program, Taipei 11529, Taiwan
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 402, Taiwan
| | | | - Anh H Ngo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Kui-Ting Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | | | - Yuki Nakamura
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
- Molecular and Biological Agricultural Sciences Program, Academia Sinica, Taiwan International Graduate Program, Taipei 11529, Taiwan
- Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
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Araguirang GE, Niemann N, Kiontke S, Eckel M, Dionisio-Sese ML, Batschauer A. The Arabidopsis cryptochrome 2 I404F mutant is hypersensitive and shows flavin reduction even in the absence of light. Planta 2019; 251:33. [PMID: 31832774 DOI: 10.1007/s00425-019-03323-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/03/2019] [Indexed: 06/10/2023]
Abstract
The cryptochrome photoreceptor mutant cry2I404F exhibits hyperactivity in the dark, hypersensitivity in different light conditions, and in contrast to the wild-type protein, its flavin chromophore is reducible even in the absence of light. Plant cryptochromes (cry) are blue-light photoreceptors involved in multiple signaling pathways and various photomorphogenic responses. One biologically hyperactive mutant of a plant cryptochrome that was previously characterized is Arabidopsis cry1L407F (Exner et al. in Plant Physiol 154:1633-1645, 2010). Protein sequence alignments of different cryptochromes revealed that L407 in cry1 corresponds to I404 in cry2. Point mutation of Ile to Phe in cry2 in this position created a novel mutant. The present study provided a baseline data on the elucidation of the properties of cry2I404F. This mutant was still able to bind ATP-triggering conformational changes, as confirmed by partial tryptic digestion and thermo-FAD assays. Surprisingly, the FAD cofactor of cry2I404F was reduced by the addition of reductant even in the absence of light. In vivo, cry2I404F exhibited a cop phenotype in the dark and hypersensitivity to various light conditions compared to cry2 wild type. Overall, these data suggest that the hypersensitivity to red and blue light and hyperactivity of this novel mutant in the dark can be mostly accounted to structural alterations brought forth by the Ile to Phe mutation at position 404 that allows reduction of the flavin chromophore even in the absence of light.
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Affiliation(s)
- Galileo Estopare Araguirang
- Graduate School, University of the Philippines Los Baños, College, 4031, Laguna, Philippines
- Department of Plant Adaptation, Leibniz-Institut für Gemüse- und Zierpflanzenbau (IGZ), Großbeeren, 14979, Germany
| | - Nils Niemann
- Department of Plant Physiology and Photobiology, Faculty of Biology, Philipps-University Marburg, 35032, Marburg, Germany
| | - Stephan Kiontke
- Department of Plant Physiology and Photobiology, Faculty of Biology, Philipps-University Marburg, 35032, Marburg, Germany
| | - Maike Eckel
- Department of Plant Physiology and Photobiology, Faculty of Biology, Philipps-University Marburg, 35032, Marburg, Germany
| | - Maribel L Dionisio-Sese
- Graduate School, University of the Philippines Los Baños, College, 4031, Laguna, Philippines
- Plant Biology Division, Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños, College, 4031, Laguna, Philippines
| | - Alfred Batschauer
- Department of Plant Physiology and Photobiology, Faculty of Biology, Philipps-University Marburg, 35032, Marburg, Germany.
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