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Shahbazi M, Majka J, Kubíková D, Zwierzykowski Z, Glombik M, Wendel JF, Sharbrough J, Hartmann S, Szecówka M, Doležel J, Bartoš J, Kopecký D, Kneřová J. Cytonuclear interplay in auto- and allopolyploids: a multifaceted perspective from the Festuca-Lolium complex. Plant J 2024; 118:1102-1118. [PMID: 38323852 DOI: 10.1111/tpj.16659] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 12/15/2023] [Accepted: 01/22/2024] [Indexed: 02/08/2024]
Abstract
Restoring cytonuclear stoichiometry is necessary after whole-genome duplication (WGD) and interspecific/intergeneric hybridization in plants. We investigated this phenomenon in auto- and allopolyploids of the Festuca-Lolium complex providing insights into the mechanisms governing cytonuclear interactions in early polyploid and hybrid generations. Our study examined the main processes potentially involved in restoring the cytonuclear balance after WGD comparing diploids and new and well-established autopolyploids. We uncovered that both the number of chloroplasts and the number of chloroplast genome copies were significantly higher in the newly established autopolyploids and grew further in more established autopolyploids. The increase in the copy number of the chloroplast genome exceeded the rise in the number of chloroplasts and fully compensated for the doubling of the nuclear genome. In addition, changes in nuclear and organelle gene expression were insignificant. Allopolyploid Festuca × Lolium hybrids displayed potential structural conflicts in parental protein variants within the cytonuclear complexes. While biased maternal allele expression has been observed in numerous hybrids, our results suggest that its role in cytonuclear stabilization in the Festuca × Lolium hybrids is limited. This study provides insights into the restoration of the cytonuclear stoichiometry, yet it emphasizes the need for future research to explore post-transcriptional regulation and its impact on cytonuclear gene expression stoichiometry. Our findings may enhance the understanding of polyploid plant evolution, with broader implications for the study of cytonuclear interactions in diverse biological contexts.
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Affiliation(s)
- Mehrdad Shahbazi
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, 77900, Olomouc, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, 61137, Brno, Czech Republic
| | - Joanna Majka
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, 77900, Olomouc, Czech Republic
- Department of Environmental Stress Biology, Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479, Poznań, Poland
| | - Denisa Kubíková
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, 77900, Olomouc, Czech Republic
| | - Zbigniew Zwierzykowski
- Department of Environmental Stress Biology, Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479, Poznań, Poland
| | - Marek Glombik
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, 77900, Olomouc, Czech Republic
- Department of Crop Genetics, John Innes Centre, Norwich, NR4 7UH, UK
| | - Jonathan F Wendel
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, Iowa, USA
| | - Joel Sharbrough
- New Mexico Institute of Mining and Technology, Biology Department, Socorro, New Mexico, 87801, USA
| | - Stephan Hartmann
- Bavarian State Research Center for Agriculture (LfL), Institute for Crop Science and Plant Breeding, Am Gereuth 4, 85354, Freising, Germany
| | - Marek Szecówka
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, 77900, Olomouc, Czech Republic
| | - Jaroslav Doležel
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, 77900, Olomouc, Czech Republic
| | - Jan Bartoš
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, 77900, Olomouc, Czech Republic
| | - David Kopecký
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, 77900, Olomouc, Czech Republic
| | - Jana Kneřová
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, 77900, Olomouc, Czech Republic
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Hurtado-Castano N, Atkins E, Barnes J, Boxall SF, Dever LV, Kneřová J, Hartwell J, Cushman JC, Borland AM. The starch-deficient plastidic PHOSPHOGLUCOMUTASE mutant of the constitutive crassulacean acid metabolism (CAM) species Kalanchoë fedtschenkoi impacts diel regulation and timing of stomatal CO2 responsiveness. Ann Bot 2023; 132:881-894. [PMID: 36661206 PMCID: PMC10799981 DOI: 10.1093/aob/mcad017] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 06/17/2023]
Abstract
BACKGROUND AND AIMS Crassulacean acid metabolism (CAM) is a specialized type of photosynthesis characterized by a diel pattern of stomatal opening at night and closure during the day, which increases water-use efficiency. Starch degradation is a key regulator of CAM, providing phosphoenolpyruvate as a substrate in the mesophyll for nocturnal assimilation of CO2. Growing recognition of a key role for starch degradation in C3 photosynthesis guard cells for mediating daytime stomatal opening presents the possibility that starch degradation might also impact CAM by regulating the provision of energy and osmolytes to increase guard cell turgor and drive stomatal opening at night. In this study, we tested the hypothesis that the timing of diel starch turnover in CAM guard cells has been reprogrammed during evolution to enable nocturnal stomatal opening and daytime closure. METHODS Biochemical and genetic characterization of wild-type and starch-deficient RNAi lines of Kalanchoë fedtschenkoi with reduced activity of plastidic phosphoglucomutase (PGM) constituted a preliminary approach for the understanding of starch metabolism and its implications for stomatal regulation in CAM plants. KEY RESULTS Starch deficiency reduced nocturnal net CO2 uptake but had negligible impact on nocturnal stomatal opening. In contrast, daytime stomatal closure was reduced in magnitude and duration in the starch-deficient rPGM RNAi lines, and their stomata were unable to remain closed in response to elevated concentrations of atmospheric CO2 administered during the day. Curtailed daytime stomatal closure was linked to higher soluble sugar contents in the epidermis and mesophyll. CONCLUSIONS Nocturnal stomatal opening is not reliant upon starch degradation, but starch biosynthesis is an important sink for carbohydrates, ensuring daytime stomatal closure in this CAM species.
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Affiliation(s)
- Natalia Hurtado-Castano
- School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne NE1 7RU, UK
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Elliott Atkins
- School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne NE1 7RU, UK
- John Innes Centre, Norwich Research Park, Colney Lane, Norwich NR4 7UH, UK
| | - Jerry Barnes
- School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne NE1 7RU, UK
| | - Susanna F Boxall
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 72B, UK
| | - Louisa V Dever
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 72B, UK
| | - Jana Kneřová
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 72B, UK
| | - James Hartwell
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 72B, UK
| | - John C Cushman
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557-0330, USA
| | - Anne M Borland
- School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne NE1 7RU, UK
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Majka J, Glombik M, Doležalová A, Kneřová J, Ferreira MTM, Zwierzykowski Z, Duchoslav M, Studer B, Doležel J, Bartoš J, Kopecký D. Both male and female meiosis contribute to non-Mendelian inheritance of parental chromosomes in interspecific plant hybrids (Lolium × Festuca). New Phytol 2023; 238:624-636. [PMID: 36658468 DOI: 10.1111/nph.18753] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [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: 11/20/2022] [Accepted: 01/14/2023] [Indexed: 06/17/2023]
Abstract
Some interspecific plant hybrids show unequal transmission of chromosomes from parental genomes to the successive generations. It has been suggested that this is due to a differential behavior of parental chromosomes during meiosis. However, underlying mechanism is unknown. We analyzed chromosome composition of the F2 generation of Festuca × Lolium hybrids and reciprocal backcrosses to elucidate effects of male and female meiosis on the shift in parental genome composition. We studied male meiosis, including the attachment of chromosomes to the karyokinetic spindle and gene expression profiling of the kinetochore genes. We found that Lolium and Festuca homoeologues were transmitted differently to the F2 generation. Female meiosis led to the replacement of Festuca chromosomes by their Lolium counterparts. In male meiosis, Festuca univalents were attached less frequently to microtubules than Lolium univalents, lagged in divisions and formed micronuclei, which were subsequently eliminated. Genome sequence analysis revealed a number of non-synonymous mutations between copies of the kinetochore genes from Festuca and Lolium genomes. Furthermore, we found that outer kinetochore proteins NDC80 and NNF1 were exclusively expressed from the Lolium allele. We hypothesize that silencing of Festuca alleles results in improper attachment of Festuca chromosomes to karyokinetic spindle and subsequently their gradual elimination.
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Affiliation(s)
- Joanna Majka
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, 77900, Olomouc, Czech Republic
- Institute of Plant Genetics, Polish Academy of Sciences, 60479, Poznan, Poland
| | - Marek Glombik
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, 77900, Olomouc, Czech Republic
- Department of Crop Genetics, John Innes Centre, Norwich. NR4 7UH, UK
| | - Alžběta Doležalová
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, 77900, Olomouc, Czech Republic
| | - Jana Kneřová
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, 77900, Olomouc, Czech Republic
| | - Marco Tulio Mendes Ferreira
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, 77900, Olomouc, Czech Republic
- Department of Biology, Federal University of Lavras, 37200-000, Lavras, MG, Brazil
| | | | - Martin Duchoslav
- Department of Botany, Palacký University, 77900, Olomouc, Czech Republic
| | - Bruno Studer
- Molecular Plant Breeding, Institute of Agricultural Sciences, ETH Zurich, 8092, Zurich, Switzerland
| | - Jaroslav Doležel
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, 77900, Olomouc, Czech Republic
| | - Jan Bartoš
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, 77900, Olomouc, Czech Republic
| | - David Kopecký
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, 77900, Olomouc, Czech Republic
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Ceusters N, Ceusters J, Hurtado-Castano N, Dever LV, Boxall SF, Kneřová J, Waller JL, Rodick R, Van den Ende W, Hartwell J, Borland AM. Phosphorolytic degradation of leaf starch via plastidic α-glucan phosphorylase leads to optimized plant growth and water use efficiency over the diel phases of Crassulacean acid metabolism. J Exp Bot 2021; 72:4419-4434. [PMID: 33754643 PMCID: PMC8266541 DOI: 10.1093/jxb/erab132] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 03/19/2021] [Indexed: 05/27/2023]
Abstract
In plants with Crassulacean acid metabolism (CAM), it has been proposed that the requirement for nocturnal provision of phosphoenolpyruvate as a substrate for CO2 uptake has resulted in a re-routing of chloroplastic starch degradation from the amylolytic route to the phosphorolytic route. To test this hypothesis, we generated and characterized four independent RNAi lines of the obligate CAM species Kalanchoë fedtschenkoi with a >10-fold reduction in transcript abundance of plastidic α-glucan phosphorylase (PHS1). The rPHS1 lines showed diminished nocturnal starch degradation, reduced dark CO2 uptake, a reduction in diel water use efficiency (WUE), and an overall reduction in growth. A re-routing of starch degradation via the hydrolytic/amylolytic pathway was indicated by hyperaccumulation of maltose in all rPHS1 lines. Further examination indicated that whilst operation of the core circadian clock was not compromised, plasticity in modulating net dark CO2 uptake in response to changing photoperiods was curtailed. The data show that phosphorolytic starch degradation is critical for efficient operation of the CAM cycle and for optimizing WUE. This finding has clear relevance for ongoing efforts to engineer CAM into non-CAM species as a means of boosting crop WUE for a warmer, drier future.
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Affiliation(s)
- Nathalie Ceusters
- Faculty of Engineering Technology, Department of Biosystems, Division of Crop Biotechnics, Campus Geel, KU Leuven, Kleinhoefstraat 4, 2440 Geel, Belgium
| | - Johan Ceusters
- Faculty of Engineering Technology, Department of Biosystems, Division of Crop Biotechnics, Campus Geel, KU Leuven, Kleinhoefstraat 4, 2440 Geel, Belgium
- UHasselt, Centre for Environmental Sciences, Environmental Biology, Campus Diepenbeek, Agoralaan Building D, 3590 Diepenbeek, Belgium
| | - Natalia Hurtado-Castano
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - Louisa V Dever
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Susanna F Boxall
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Jana Kneřová
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Jade L Waller
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Rebecca Rodick
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Wim Van den Ende
- Faculty of Science, Department of Biology, Laboratory of Molecular Plant Biology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Heverlee, Belgium
| | - James Hartwell
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Anne M Borland
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
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5
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Dickinson PJ, Kneřová J, Szecówka M, Stevenson SR, Burgess SJ, Mulvey H, Bågman AM, Gaudinier A, Brady SM, Hibberd JM. A bipartite transcription factor module controlling expression in the bundle sheath of Arabidopsis thaliana. Nat Plants 2020; 6:1468-1479. [PMID: 33230313 DOI: 10.1038/s41477-020-00805-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 10/14/2020] [Indexed: 06/11/2023]
Abstract
C4 photosynthesis evolved repeatedly from the ancestral C3 state, improving photosynthetic efficiency by ~50%. In most C4 lineages, photosynthesis is compartmented between mesophyll and bundle sheath cells, but how gene expression is restricted to these cell types is poorly understood. Using the C3 model Arabidopsis thaliana, we identified cis-elements and transcription factors driving expression in bundle sheath strands. Upstream of the bundle sheath preferentially expressed MYB76 gene, we identified a region necessary and sufficient for expression containing two cis-elements associated with the MYC and MYB families of transcription factors. MYB76 expression is reduced in mutant alleles for these transcription factors. Moreover, downregulated genes shared by both mutants are preferentially expressed in the bundle sheath. Our findings are broadly relevant for understanding the spatial patterning of gene expression, provide specific insights into mechanisms associated with the evolution of C4 photosynthesis and identify a short tuneable sequence for manipulating gene expression in the bundle sheath.
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Affiliation(s)
| | - Jana Kneřová
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Marek Szecówka
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Sean R Stevenson
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Steven J Burgess
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Hugh Mulvey
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Anne-Maarit Bågman
- Department of Plant Biology and Genome Center, University of California, Davis, CA, USA
| | - Allison Gaudinier
- Department of Plant Biology and Genome Center, University of California, Davis, CA, USA
| | - Siobhan M Brady
- Department of Plant Biology and Genome Center, University of California, Davis, CA, USA
| | - Julian M Hibberd
- Department of Plant Sciences, University of Cambridge, Cambridge, UK.
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6
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Boxall SF, Kadu N, Dever LV, Kneřová J, Waller JL, Gould PJD, Hartwell J. Kalanchoë PPC1 Is Essential for Crassulacean Acid Metabolism and the Regulation of Core Circadian Clock and Guard Cell Signaling Genes. Plant Cell 2020; 32:1136-1160. [PMID: 32051209 PMCID: PMC7145507 DOI: 10.1105/tpc.19.00481] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 01/28/2020] [Accepted: 02/09/2020] [Indexed: 05/21/2023]
Abstract
Unlike C3 plants, Crassulacean acid metabolism (CAM) plants fix CO2 in the dark using phosphoenolpyruvate carboxylase (PPC; EC 4.1.1.31). PPC combines phosphoenolpyruvate with CO2 (as HCO3 -), forming oxaloacetate. The oxaloacetate is converted to malate, leading to malic acid accumulation in the vacuole, which peaks at dawn. During the light period, malate decarboxylation concentrates CO2 around Rubisco for secondary fixation. CAM mutants lacking PPC have not been described. Here, we employed RNA interference to silence the CAM isogene PPC1 in Kalanchoë laxiflora Line rPPC1-B lacked PPC1 transcripts, PPC activity, dark period CO2 fixation, and nocturnal malate accumulation. Light period stomatal closure was also perturbed, and the plants displayed reduced but detectable dark period stomatal conductance and arrhythmia of the CAM CO2 fixation circadian rhythm under constant light and temperature free-running conditions. By contrast, the rhythm of delayed fluorescence was enhanced in plants lacking PPC1 Furthermore, a subset of gene transcripts within the central circadian oscillator was upregulated and oscillated robustly in this line. The regulation of guard cell genes involved in controlling stomatal movements was also perturbed in rPPC1-B These findings provide direct evidence that the regulatory patterns of key guard cell signaling genes are linked with the characteristic inverse pattern of stomatal opening and closing during CAM.
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Affiliation(s)
- Susanna F Boxall
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Nirja Kadu
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Louisa V Dever
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Jana Kneřová
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Jade L Waller
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Peter J D Gould
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - James Hartwell
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
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7
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Borba AR, Serra TS, Górska A, Gouveia P, Cordeiro AM, Reyna-Llorens I, Kneřová J, Barros PM, Abreu IA, Oliveira MM, Hibberd JM, Saibo NJM. Synergistic Binding of bHLH Transcription Factors to the Promoter of the Maize NADP-ME Gene Used in C4 Photosynthesis Is Based on an Ancient Code Found in the Ancestral C3 State. Mol Biol Evol 2018; 35:1690-1705. [PMID: 29659975 PMCID: PMC5995220 DOI: 10.1093/molbev/msy060] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
C4 photosynthesis has evolved repeatedly from the ancestral C3 state to generate a carbon concentrating mechanism that increases photosynthetic efficiency. This specialized form of photosynthesis is particularly common in the PACMAD clade of grasses, and is used by many of the world's most productive crops. The C4 cycle is accomplished through cell-type-specific accumulation of enzymes but cis-elements and transcription factors controlling C4 photosynthesis remain largely unknown. Using the NADP-Malic Enzyme (NADP-ME) gene as a model we tested whether mechanisms impacting on transcription in C4 plants evolved from ancestral components found in C3 species. Two basic Helix-Loop-Helix (bHLH) transcription factors, ZmbHLH128 and ZmbHLH129, were shown to bind the C4NADP-ME promoter from maize. These proteins form heterodimers and ZmbHLH129 impairs trans-activation by ZmbHLH128. Electrophoretic mobility shift assays indicate that a pair of cis-elements separated by a seven base pair spacer synergistically bind either ZmbHLH128 or ZmbHLH129. This pair of cis-elements is found in both C3 and C4 Panicoid grass species of the PACMAD clade. Our analysis is consistent with this cis-element pair originating from a single motif present in the ancestral C3 state. We conclude that C4 photosynthesis has co-opted an ancient C3 regulatory code built on G-box recognition by bHLH to regulate the NADP-ME gene. More broadly, our findings also contribute to the understanding of gene regulatory networks controlling C4 photosynthesis.
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Affiliation(s)
- Ana Rita Borba
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
| | - Tânia S Serra
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
| | - Alicja Górska
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
| | - Paulo Gouveia
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
| | - André M Cordeiro
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
| | - Ivan Reyna-Llorens
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Jana Kneřová
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Pedro M Barros
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Isabel A Abreu
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
| | - Maria Margarida Oliveira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
| | - Julian M Hibberd
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Nelson J M Saibo
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
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8
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Boxall SF, Dever LV, Kneřová J, Gould PD, Hartwell J. Phosphorylation of Phospho enolpyruvate Carboxylase Is Essential for Maximal and Sustained Dark CO 2 Fixation and Core Circadian Clock Operation in the Obligate Crassulacean Acid Metabolism Species Kalanchoë fedtschenkoi. Plant Cell 2017; 29:2519-2536. [PMID: 28887405 PMCID: PMC5774574 DOI: 10.1105/tpc.17.00301] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 07/25/2017] [Accepted: 09/04/2017] [Indexed: 05/14/2023]
Abstract
Phosphoenolpyruvate carboxylase (PPC; EC 4.1.1.31) catalyzes primary nocturnal CO2 fixation in Crassulacean acid metabolism (CAM) species. CAM PPC is regulated posttranslationally by a circadian clock-controlled protein kinase called phosphoenolpyruvate carboxylase kinase (PPCK). PPCK phosphorylates PPC during the dark period, reducing its sensitivity to feedback inhibition by malate and thus enhancing nocturnal CO2 fixation to stored malate. Here, we report the generation and characterization of transgenic RNAi lines of the obligate CAM species Kalanchoë fedtschenkoi with reduced levels of KfPPCK1 transcripts. Plants with reduced or no detectable dark phosphorylation of PPC displayed up to a 66% reduction in total dark period CO2 fixation. These perturbations paralleled reduced malate accumulation at dawn and decreased nocturnal starch turnover. Loss of oscillations in the transcript abundance of KfPPCK1 was accompanied by a loss of oscillations in the transcript abundance of many core circadian clock genes, suggesting that perturbing the only known link between CAM and the circadian clock feeds back to perturb the central circadian clock itself. This work shows that clock control of KfPPCK1 prolongs the activity of PPC throughout the dark period in K. fedtschenkoi, optimizing CAM-associated dark CO2 fixation, malate accumulation, CAM productivity, and core circadian clock robustness.
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Affiliation(s)
- Susanna F Boxall
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Louisa V Dever
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Jana Kneřová
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Peter D Gould
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - James Hartwell
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
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Dever LV, Boxall SF, Kneřová J, Hartwell J. Transgenic perturbation of the decarboxylation phase of Crassulacean acid metabolism alters physiology and metabolism but has only a small effect on growth. Plant Physiol 2015; 167:44-59. [PMID: 25378692 PMCID: PMC4281012 DOI: 10.1104/pp.114.251827] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 10/28/2014] [Indexed: 05/19/2023]
Abstract
Mitochondrial NAD-malic enzyme (ME) and/or cytosolic/plastidic NADP-ME combined with the cytosolic/plastidic pyruvate orthophosphate dikinase (PPDK) catalyze two key steps during light-period malate decarboxylation that underpin secondary CO(2) fixation in some Crassulacean acid metabolism (CAM) species. We report the generation and phenotypic characterization of transgenic RNA interference lines of the obligate CAM species Kalanchoë fedtschenkoi with reduced activities of NAD-ME or PPDK. Transgenic line rNAD-ME1 had 8%, and rPPDK1 had 5% of the wild-type level of activity, and showed dramatic changes in the light/dark cycle of CAM CO(2) fixation. In well-watered conditions, these lines fixed all of their CO(2) in the light; they thus performed C(3) photosynthesis. The alternative malate decarboxylase, NADP-ME, did not appear to compensate for the reduction in NAD-ME, suggesting that NAD-ME was the key decarboxylase for CAM. The activity of other CAM enzymes was reduced as a consequence of knocking out either NAD-ME or PPDK activity, particularly phosphoenolpyruvate carboxylase (PPC) and PPDK in rNAD-ME1. Furthermore, the circadian clock-controlled phosphorylation of PPC in the dark was reduced in both lines, especially in rNAD-ME1. This had the consequence that circadian rhythms of PPC phosphorylation, PPC kinase transcript levels and activity, and the classic circadian rhythm of CAM CO(2) fixation were lost, or dampened toward arrhythmia, under constant light and temperature conditions. Surprisingly, oscillations in the transcript abundance of core circadian clock genes also became arrhythmic in the rNAD-ME1 line, suggesting that perturbing CAM in K. fedtschenkoi feeds back to perturb the central circadian clock.
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Affiliation(s)
- Louisa V Dever
- Department of Plant Sciences, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Susanna F Boxall
- Department of Plant Sciences, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Jana Kneřová
- Department of Plant Sciences, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - James Hartwell
- Department of Plant Sciences, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
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Abstract
There is currently significant interest in engineering the two-celled C4 photosynthesis pathway into crops such as rice in order to increase yield. This will require alterations to the biochemistry of photosynthesis in both mesophyll (M) and bundle-sheath (BS) cells, but also alterations to leaf anatomy. For example, the BS of C4 species is enlarged compared with that in C3 species. Because cell and nucleus size are often correlated, this study investigated whether nuclear endoreduplication is associated with increased differentiation and expansion of BS cells. Nuclei in the BS of C4 Cleome gynandra were tagged with green fluorescent protein. Confocal laser-scanning microscopy and flow cytometry of isolated nuclei were used to quantify size and DNA content in BS cells. The results showed a significant endoreduplication in BS cells of C. gynandra but not in additional C4 lineages from both the monocotyledonous and dicotyledenous plants. Furthermore, in the C3 species Arabidopsis thaliana, BS cells undergo endoreduplication. Due to this significant endoreduplication in the small BS cells of C3 A. thaliana, it was concluded that endoreduplication of BS nuclei in C4 plants is not linked to expansion and differentiation of BS cells, and therefore that alternative strategies to increase this compartment need to be sought in order to engineer C4 traits into C3 crops such as rice.
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Affiliation(s)
- Sylvain Aubry
- Department of Plant Sciences, Downing Street, University of Cambridge, Cambridge CB2 3EA, UK
| | - Jana Kneřová
- Department of Plant Sciences, Downing Street, University of Cambridge, Cambridge CB2 3EA, UK
| | - Julian M Hibberd
- Department of Plant Sciences, Downing Street, University of Cambridge, Cambridge CB2 3EA, UK
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Covshoff S, Burgess SJ, Kneřová J, Kümpers BMC. Getting the most out of natural variation in C4 photosynthesis. Photosynth Res 2014; 119:157-167. [PMID: 23794170 DOI: 10.1007/s11120-013-9872-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 06/12/2013] [Indexed: 06/02/2023]
Abstract
C4 photosynthesis is a complex trait that has a high degree of natural variation, involving anatomical and biochemical changes relative to the ancestral C3 state. It has evolved at least 66 times across a variety of lineages and the evolutionary route from C3 to C4 is likely conserved but not necessarily genetically identical. As such, a variety of C4 species are needed to identify what is fundamental to the C4 evolutionary process in a global context. In order to identify the genetic components of C4 form and function, a number of species are used as genetic models. These include Zea mays (maize), Sorghum bicolor (sorghum), Setaria viridis (Setaria), Flaveria bidentis, and Cleome gynandra. Each of these species has different benefits and challenges associated with its use as a model organism. Here, we propose that RNA profiling of a large sampling of C4, C3-C4, and C3 species, from as many lineages as possible, will allow identification of candidate genes necessary and sufficient to confer C4 anatomy and/or biochemistry. Furthermore, C4 model species will play a critical role in the functional characterization of these candidate genes and identification of their regulatory elements, by providing a platform for transformation and through the use of gene expression profiles in mesophyll and bundle sheath cells and along the leaf developmental gradient. Efforts should be made to sequence the genomes of F. bidentis and C. gynandra and to develop congeneric C3 species as genetic models for comparative studies. In combination, such resources would facilitate discovery of common and unique C4 regulatory mechanisms across genera.
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Affiliation(s)
- Sarah Covshoff
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK,
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