1
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Rojas M, Chotewutmontri P, Barkan A. Translational activation by a synthetic PPR protein elucidates control of psbA translation in Arabidopsis chloroplasts. THE PLANT CELL 2024; 36:4168-4178. [PMID: 38593198 PMCID: PMC11449048 DOI: 10.1093/plcell/koae112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/11/2024] [Accepted: 03/22/2024] [Indexed: 04/11/2024]
Abstract
Translation initiation on chloroplast psbA mRNA in plants scales with light intensity, providing its gene product, D1, as needed to replace photodamaged D1 in Photosystem II. The psbA translational activator HIGH CHLOROPHYLL FLUORESCENCE 173 (HCF173) has been hypothesized to mediate this regulation. HCF173 belongs to the short-chain dehydrogenase/reductase superfamily, associates with the psbA 5'-untranslated region (5'-UTR), and has been hypothesized to enhance translation by binding an RNA segment that would otherwise pair with and mask the ribosome binding region. To test these hypotheses, we examined whether a synthetic pentatricopeptide repeat (sPPR) protein can substitute for HCF173 when bound to the HCF173 binding site. We show that an sPPR designed to bind HCF173's footprint in the psbA 5'-UTR bound the intended site in vivo and partially substituted for HCF173 to activate psbA translation. However, sPPR-activated translation did not respond to light. These results imply that HCF173 activates translation, at least in part, by sequestering the RNA it binds to maintain an accessible ribosome binding region, and that HCF173 is also required to regulate psbA translation in response to light. Translational activation can be added to the functions that can be programmed with sPPR proteins for synthetic biology applications in chloroplasts.
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Affiliation(s)
- Margarita Rojas
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97405, USA
| | | | - Alice Barkan
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97405, USA
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2
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Xu C, Wang JC, Sun L, Zhuang LH, Guo ZJ, Ding QS, Ma DN, Song LY, Li J, Tang HC, Zhu XY, Zheng HL. Genome-Wide Identification of Pentatricopeptide Repeat (PPR) Gene Family and Multi-Omics Analysis Provide New Insights Into the Albinism Mechanism of Kandelia obovata Propagule Leaves. PLANT, CELL & ENVIRONMENT 2024. [PMID: 39222055 DOI: 10.1111/pce.15132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Revised: 07/29/2024] [Accepted: 08/19/2024] [Indexed: 09/04/2024]
Abstract
Pentatricopeptide repeat (PPR) gene family constitutes one of the largest gene families in plants, which mainly participate in RNA editing and RNA splicing of organellar RNAs, thereby affecting the organellar development. Recently, some evidence elucidated the important roles of PPR proteins in the albino process of plant leaves. However, the functions of PPR genes in the woody mangrove species have not been investigated. In this study, using a typical true mangrove Kandelia obovata, we systematically identified 298 PPR genes and characterized their general features and physicochemical properties, including evolutionary relationships, the subcellular localization, PPR motif type, the number of introns and PPR motifs, and isoelectric point, and so forth. Furthermore, we combined genome-wide association studies (GWAS) and transcriptome analysis to identify the genetic architecture and potential PPR genes associated with propagule leaves colour variations of K. obovata. As a result, we prioritized 16 PPR genes related to the albino phenotype using different strategies, including differentially expressed genes analysis and genetic diversity analysis. Further analysis discovered two genes of interest, namely Maker00002998 (PLS-type) and Maker00003187 (P-type), which were differentially expressed genes and causal genes detected by GWAS analysis. Moreover, we successfully predicted downstream target chloroplast genes (rps14, rpoC1 and rpoC2) bound by Maker00002998 PPR proteins. The experimental verification of RNA editing sites of rps14, rpoC1, and rpoC2 in our previous study and the verification of interaction between Maker00002998 and rps14 transcript using in vitro RNA pull-down assays revealed that Maker00002998 PPR protein might be involved in the post-transcriptional process of chloroplast genes. Our result provides new insights into the roles of PPR genes in the albinism mechanism of K. obovata propagule leaves.
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Affiliation(s)
- Chaoqun Xu
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Ji-Cheng Wang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Ling Sun
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Li-Han Zhuang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Ze-Jun Guo
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, China
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, School of Marine Sciences, Coral Reef Research Center of China, Guangxi University, Nanning, China
| | - Qian-Su Ding
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Dong-Na Ma
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, China
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
| | - Ling-Yu Song
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Jing Li
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Han-Chen Tang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Xue-Yi Zhu
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Hai-Lei Zheng
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, China
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3
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Mirzaee M, Leung A, Parulekar M, Candia A, Matsuoka A, Lutz KA, Maliga P. Seed plastids: A novel platform for recombinant protein expression. PLANT BIOTECHNOLOGY JOURNAL 2024; 22:2575-2577. [PMID: 38803087 PMCID: PMC11331780 DOI: 10.1111/pbi.14369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 04/11/2024] [Accepted: 04/22/2024] [Indexed: 05/29/2024]
Affiliation(s)
- Malihe Mirzaee
- Waksman Institute of Microbiology, Rutgers UniversityPiscatawayNew JerseyUSA
| | - Alyssa Leung
- Waksman Institute of Microbiology, Rutgers UniversityPiscatawayNew JerseyUSA
| | - Mugdha Parulekar
- Waksman Institute of Microbiology, Rutgers UniversityPiscatawayNew JerseyUSA
| | - Ana Candia
- Department of Biology, Farmingdale State CollegeFarmingdaleNew YorkUSA
| | - Aki Matsuoka
- Waksman Institute of Microbiology, Rutgers UniversityPiscatawayNew JerseyUSA
| | - Kerry A. Lutz
- Department of Biology, Farmingdale State CollegeFarmingdaleNew YorkUSA
| | - Pal Maliga
- Waksman Institute of Microbiology, Rutgers UniversityPiscatawayNew JerseyUSA
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4
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Yu Q, Tungsuchat-Huang T, Ioannou A, Barkan A, Maliga P. Posttranscriptional tuning of gene expression over a large dynamic range in synthetic tobacco chloroplast operons. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 119:2437-2449. [PMID: 39031552 DOI: 10.1111/tpj.16930] [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: 03/06/2024] [Revised: 06/02/2024] [Accepted: 07/01/2024] [Indexed: 07/22/2024]
Abstract
Achieving optimally balanced gene expression within synthetic operons requires regulatory elements capable of providing a spectrum of expression levels. In this study, we investigate the expression of gfp reporter gene in tobacco chloroplasts, guided by variants of the plastid atpH 5' UTR, which harbors a binding site for PPR10, a protein that activates atpH at the posttranscriptional level. Our findings reveal that endogenous tobacco PPR10 confers distinct levels of reporter activation when coupled with the tobacco and maize atpH 5' UTRs in different design contexts. Notably, high GFP expression was not coupled to the stabilization of monocistronic gfp transcripts in dicistronic reporter lines, adding to the evidence that PPR10 activates translation via a mechanism that is independent of its stabilization of monocistronic transcripts. Furthermore, the incorporation of a tRNA upstream of the UTR nearly abolishes gfp mRNA (and GFP protein), presumably by promoting such rapid RNA cleavage and 5' exonucleolytic degradation that PPR10 had insufficient time to bind and protect gfp RNA, resulting in a substantial reduction in GFP accumulation. When combined with a mutant atpH 5' UTR, the tRNA leads to an exceptionally low level of transgene expression. Collectively, this approach allows for tuning of reporter gene expression across a wide range, spanning from a mere 0.02-25% of the total soluble cellular protein. These findings highlight the potential of employing cis-elements from heterologous species and expand the toolbox available for plastid synthetic biology applications requiring multigene expression at varying levels.
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Affiliation(s)
- Qiguo Yu
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey, 08854, USA
| | | | - Alexander Ioannou
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey, 08854, USA
| | - Alice Barkan
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, 97403, USA
| | - Pal Maliga
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey, 08854, USA
- Department of Plant Biology, Rutgers University, New Brunswick, New Jersey, 08901, USA
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5
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Wei Y, Li X, Li D, Su X, Huang Y, Li Q, Liang M, Yang X. Mapping and Candidate Gene Analysis of the Low-Temperature-Sensitive Albino Gene OsLTSA8 in Rice Seedlings. Curr Issues Mol Biol 2024; 46:6508-6521. [PMID: 39057030 PMCID: PMC11275959 DOI: 10.3390/cimb46070388] [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: 05/12/2024] [Revised: 06/19/2024] [Accepted: 06/24/2024] [Indexed: 07/28/2024] Open
Abstract
Chloroplasts are organelles responsible for photosynthesis in plants, providing energy for growth and development. However, the genetic regulatory mechanisms underlying early chloroplast development in rice remain incompletely understood. In this study, we identified a rice seedling thermosensitive chlorophyll-deficient mutant, osltsa8, and the genetic analysis of two F2 populations suggested that this trait may be controlled by more than one pair of alleles. Through reciprocal F2 populations and QTL-seq technology, OsLTSA8 was mapped to the interval of 24,280,402-25,920,942 bp on rice chromosome 8, representing a novel albino gene in rice. Within the candidate gene region of OsLTSA8, there were 258 predicted genes, among which LOC_Os08g39050, LOC_Os08g39130, and LOC_Os08g40870 encode pentatricopeptide repeat (PPR) proteins. RNA-seq identified 18 DEGs (differentially expressed genes) within the candidate interval, with LOC_Os08g39420 showing homology to the pigment biosynthesis-related genes Zm00001d017656 and Sb01g000470; LOC_Os08g39430 and LOC_Os08g39850 were implicated in chlorophyll precursor synthesis. RT-qPCR was employed to assess the expression levels of LOC_Os08g39050, LOC_Os08g39130, LOC_Os08g40870, LOC_Os08g39420, LOC_Os08g39430, and LOC_Os08g39850 in the wild-type and mutant plants. Among them, the differences in the expression levels of LOC_Os08g39050 and LOC_Os08g39430 were the most significant. This study will contribute to further elucidating the molecular mechanisms of rice chloroplast development.
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Affiliation(s)
- Yu Wei
- Guangxi Key Laboratory of Rice Genetics and Breeding, Rice Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; (Y.W.); (X.L.); (D.L.); (X.S.); (Y.H.); (Q.L.); (M.L.)
- State Key Laboratory for Conservation and Utillzation of Subtropical Agro-Bioresources, Nanning 530007, China
| | - Xiaoqiong Li
- Guangxi Key Laboratory of Rice Genetics and Breeding, Rice Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; (Y.W.); (X.L.); (D.L.); (X.S.); (Y.H.); (Q.L.); (M.L.)
- State Key Laboratory for Conservation and Utillzation of Subtropical Agro-Bioresources, Nanning 530007, China
| | - Dongxiu Li
- Guangxi Key Laboratory of Rice Genetics and Breeding, Rice Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; (Y.W.); (X.L.); (D.L.); (X.S.); (Y.H.); (Q.L.); (M.L.)
| | - Xuejun Su
- Guangxi Key Laboratory of Rice Genetics and Breeding, Rice Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; (Y.W.); (X.L.); (D.L.); (X.S.); (Y.H.); (Q.L.); (M.L.)
| | - Yunchuan Huang
- Guangxi Key Laboratory of Rice Genetics and Breeding, Rice Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; (Y.W.); (X.L.); (D.L.); (X.S.); (Y.H.); (Q.L.); (M.L.)
| | - Qiuwen Li
- Guangxi Key Laboratory of Rice Genetics and Breeding, Rice Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; (Y.W.); (X.L.); (D.L.); (X.S.); (Y.H.); (Q.L.); (M.L.)
| | - Manling Liang
- Guangxi Key Laboratory of Rice Genetics and Breeding, Rice Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; (Y.W.); (X.L.); (D.L.); (X.S.); (Y.H.); (Q.L.); (M.L.)
| | - Xinghai Yang
- Guangxi Key Laboratory of Rice Genetics and Breeding, Rice Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; (Y.W.); (X.L.); (D.L.); (X.S.); (Y.H.); (Q.L.); (M.L.)
- State Key Laboratory for Conservation and Utillzation of Subtropical Agro-Bioresources, Nanning 530007, China
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6
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Raza A, Siddique KHM, Hu Z. Chloroplast gene control: unlocking RNA thermometer mechanisms in photosynthetic systems. TRENDS IN PLANT SCIENCE 2024; 29:623-625. [PMID: 38311501 DOI: 10.1016/j.tplants.2024.01.005] [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: 12/12/2023] [Revised: 01/16/2024] [Accepted: 01/23/2024] [Indexed: 02/06/2024]
Abstract
RNA thermometers offer straightforward, protein-independent methods to regulate gene expression at the post-transcriptional level. In this context, Chung and colleagues have discovered a revolutionary RNA thermometer in the chloroplast genome of Chlamydomonas reinhardtii. This will facilitate temperature-driven control of inducible transgene expression for biotechnology applications in plant and algal systems.
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Affiliation(s)
- Ali Raza
- Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Guangdong Technology Research Center for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China; College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China; Shenzhen Collaborative Innovation Public Service Platform for Marine Algae Industry, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
| | - Kadambot H M Siddique
- The UWA Institute of Agriculture, The University of Western Australia, Crawley, Perth 6009, Australia
| | - Zhangli Hu
- Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Guangdong Technology Research Center for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China; Shenzhen Collaborative Innovation Public Service Platform for Marine Algae Industry, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China.
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7
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Kwok van der Giezen F, Honkanen S, Colas des Francs-Small C, Bond C, Small I. Applications of Synthetic Pentatricopeptide Repeat Proteins. PLANT & CELL PHYSIOLOGY 2024; 65:503-515. [PMID: 38035801 PMCID: PMC11094755 DOI: 10.1093/pcp/pcad150] [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: 07/31/2023] [Revised: 11/20/2023] [Accepted: 11/29/2023] [Indexed: 12/02/2023]
Abstract
RNA-binding proteins play integral roles in the regulation of essential processes in cells and as such are attractive targets for engineering to manipulate gene expression at the RNA level. Expression of transcripts in chloroplasts and mitochondria is heavily regulated by pentatricopeptide repeat (PPR) proteins. The diverse roles of PPR proteins and their naturally modular architecture make them ideal candidates for engineering. Synthetic PPR proteins are showing great potential to become valuable tools for controlling the expression of plastid and mitochondrial transcripts. In this review, by 'synthetic', we mean both rationally modified natural PPR proteins and completely novel proteins designed using the principles learned from their natural counterparts. We focus on the many different applications of synthetic PPR proteins, covering both their use in basic research to learn more about protein-RNA interactions and their use to achieve specific outcomes in RNA processing and the control of gene expression. We describe the challenges associated with the design, construction and deployment of synthetic PPR proteins and provide perspectives on how they might be assembled and used in future biotechnology applications.
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Affiliation(s)
- Farley Kwok van der Giezen
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
| | - Suvi Honkanen
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
| | - Catherine Colas des Francs-Small
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
| | - Charles Bond
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
| | - Ian Small
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
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8
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Xu W, Li S, Bock R, Zhang J. A heat-inducible expression system for external control of gene expression in plastids. PLANT BIOTECHNOLOGY JOURNAL 2024; 22:960-969. [PMID: 38059318 PMCID: PMC10955493 DOI: 10.1111/pbi.14238] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 10/17/2023] [Accepted: 11/04/2023] [Indexed: 12/08/2023]
Abstract
Inducible expression systems can overcome the trade-off between high-level transgene expression and its pleiotropic effects on plant growth. In addition, they can facilitate the expression of biochemical pathways that produce toxic metabolites. Although a few inducible expression systems for the control of transgene expression in plastids have been developed, they all depend on chemical inducers and/or nuclear transgenes. Here we report a temperature-inducible expression system for plastids that is based on the bacteriophage λ leftward and rightward promoters (pL/pR) and the temperature-sensitive repressor cI857. We show that the expression of green fluorescent protein (GFP) in plastids can be efficiently repressed by cI857 under normal growth conditions, and becomes induced over time upon exposure to elevated temperatures in a light-dependent process. We further demonstrate that by introducing into plastids an expression system based on the bacteriophage T7 RNA polymerase, the temperature-dependent accumulation of GFP increased further and was ~24 times higher than expression driven by the pL/pR promoter alone, reaching ~0.48% of the total soluble protein. In conclusion, our heat-inducible expression system provides a new tool for the external control of plastid (trans) gene expression that is cost-effective and does not depend on chemical inducers.
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Affiliation(s)
- Wenbo Xu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, School of Life SciencesHubei UniversityWuhanChina
| | - Shengchun Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, School of Life SciencesHubei UniversityWuhanChina
| | - Ralph Bock
- Max‐Planck‐Institut für Molekulare PflanzenphysiologiePotsdam‐GolmGermany
| | - Jiang Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, School of Life SciencesHubei UniversityWuhanChina
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhenChina
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9
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Yang F, Vincis Pereira Sanglard L, Lee CP, Ströher E, Singh S, Oh GGK, Millar AH, Small I, Colas des Francs-Small C. Mitochondrial atp1 mRNA knockdown by a custom-designed pentatricopeptide repeat protein alters ATP synthase. PLANT PHYSIOLOGY 2024; 194:2631-2647. [PMID: 38206203 PMCID: PMC10980415 DOI: 10.1093/plphys/kiae008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 11/28/2023] [Accepted: 11/30/2023] [Indexed: 01/12/2024]
Abstract
Spontaneous mutations are rare in mitochondria and the lack of mitochondrial transformation methods has hindered genetic analyses. We show that a custom-designed RNA-binding pentatricopeptide repeat (PPR) protein binds and specifically induces cleavage of ATP synthase subunit1 (atp1) mRNA in mitochondria, significantly decreasing the abundance of the Atp1 protein and the assembled F1Fo ATP synthase in Arabidopsis (Arabidopsis thaliana). The transformed plants are characterized by delayed vegetative growth and reduced fertility. Five-fold depletion of Atp1 level was accompanied by a decrease in abundance of other ATP synthase subunits and lowered ATP synthesis rate of isolated mitochondria, but no change to mitochondrial electron transport chain complexes, adenylates, or energy charge in planta. Transcripts for amino acid transport and a variety of stress response processes were differentially expressed in lines containing the PPR protein, indicating changes to achieve cellular homeostasis when ATP synthase was highly depleted. Leaves of ATP synthase-depleted lines showed higher respiratory rates and elevated steady-state levels of numerous amino acids, most notably of the serine family. The results show the value of using custom-designed PPR proteins to influence the expression of specific mitochondrial transcripts to carry out reverse genetic studies on mitochondrial gene functions and the consequences of ATP synthase depletion on cellular functions in Arabidopsis.
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Affiliation(s)
- Fei Yang
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming 650201, P. R. China
| | - Lilian Vincis Pereira Sanglard
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Chun-Pong Lee
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Elke Ströher
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Swati Singh
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Glenda Guec Khim Oh
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - A Harvey Millar
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Ian Small
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Catherine Colas des Francs-Small
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia
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10
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Tanwar N, Arya SS, Rookes JE, Cahill DM, Lenka SK, Bansal KC. Prospects of chloroplast metabolic engineering for developing nutrient-dense food crops. Crit Rev Biotechnol 2023; 43:1001-1018. [PMID: 35815847 DOI: 10.1080/07388551.2022.2092717] [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: 01/31/2022] [Accepted: 05/29/2022] [Indexed: 11/03/2022]
Abstract
Addressing nutritional deficiencies in food crops through biofortification is a sustainable approach to tackling malnutrition. Biofortification is continuously being attempted through conventional breeding as well as through various plant biotechnological interventions, ranging from molecular breeding to genetic engineering and genome editing for enriching crops with various health-promoting metabolites. Genetic engineering is used for the rational incorporation of desired nutritional traits in food crops and predominantly operates through nuclear and chloroplast genome engineering. In the recent past, chloroplast engineering has been deployed as a strategic tool to develop model plants with enhanced nutritional traits due to the various advantages it offers over nuclear genome engineering. However, this approach needs to be extended for the nutritional enhancement of major food crops. Further, this platform could be combined with strategies, such as synthetic biology, chloroplast editing, nanoparticle-mediated rapid chloroplast transformation, and horizontal gene transfer through grafting for targeting endogenous metabolic pathways for overproducing native nutraceuticals, production of biopharmaceuticals, and biosynthesis of designer nutritional compounds. This review focuses on exploring various features of chloroplast genome engineering for nutritional enhancement of food crops by enhancing the levels of existing metabolites, restoring the metabolites lost during crop domestication, and introducing novel metabolites and phytonutrients needed for a healthy daily diet.
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Affiliation(s)
- Neha Tanwar
- TERI-Deakin Nano-Biotechnology Centre, The Energy Resources Institute (TERI), New Delhi, India
- School of Life and Environmental Sciences, Deakin University, Waurn Ponds Campus, Geelong, Australia
| | - Sagar S Arya
- School of Life and Environmental Sciences, Deakin University, Waurn Ponds Campus, Geelong, Australia
| | - James E Rookes
- School of Life and Environmental Sciences, Deakin University, Waurn Ponds Campus, Geelong, Australia
| | - David M Cahill
- School of Life and Environmental Sciences, Deakin University, Waurn Ponds Campus, Geelong, Australia
| | - Sangram K Lenka
- TERI-Deakin Nano-Biotechnology Centre, The Energy Resources Institute (TERI), New Delhi, India
- Gujarat Biotechnology University, Gujarat, India
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11
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Chung KP, Loiacono FV, Neupert J, Wu M, Bock R. An RNA thermometer in the chloroplast genome of Chlamydomonas facilitates temperature-controlled gene expression. Nucleic Acids Res 2023; 51:11386-11400. [PMID: 37855670 PMCID: PMC10639063 DOI: 10.1093/nar/gkad816] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/01/2023] [Accepted: 09/20/2023] [Indexed: 10/20/2023] Open
Abstract
Riboregulators such as riboswitches and RNA thermometers provide simple, protein-independent tools to control gene expression at the post-transcriptional level. In bacteria, RNA thermometers regulate protein synthesis in response to temperature shifts. Thermometers outside of the bacterial world are rare, and in organellar genomes, no RNA thermometers have been identified to date. Here we report the discovery of an RNA thermometer in a chloroplast gene of the unicellular green alga Chlamydomonas reinhardtii. The thermometer, residing in the 5' untranslated region of the psaA messenger RNA forms a hairpin-type secondary structure that masks the Shine-Dalgarno sequence at 25°C. At 40°C, melting of the secondary structure increases accessibility of the Shine-Dalgarno sequence to initiating ribosomes, thus enhancing protein synthesis. By targeted nucleotide substitutions and transfer of the thermometer into Escherichia coli, we show that the secondary structure is necessary and sufficient to confer the thermometer properties. We also demonstrate that the thermometer provides a valuable tool for inducible transgene expression from the Chlamydomonas plastid genome, in that a simple temperature shift of the algal culture can greatly increase recombinant protein yields.
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Affiliation(s)
- Kin Pan Chung
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - F Vanessa Loiacono
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Juliane Neupert
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Mengting Wu
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
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12
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Zhang Y, Tian L, Lu C. Chloroplast gene expression: Recent advances and perspectives. PLANT COMMUNICATIONS 2023; 4:100611. [PMID: 37147800 PMCID: PMC10504595 DOI: 10.1016/j.xplc.2023.100611] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 04/11/2023] [Accepted: 05/01/2023] [Indexed: 05/07/2023]
Abstract
Chloroplasts evolved from an ancient cyanobacterial endosymbiont more than 1.5 billion years ago. During subsequent coevolution with the nuclear genome, the chloroplast genome has remained independent, albeit strongly reduced, with its own transcriptional machinery and distinct features, such as chloroplast-specific innovations in gene expression and complicated post-transcriptional processing. Light activates the expression of chloroplast genes via mechanisms that optimize photosynthesis, minimize photodamage, and prioritize energy investments. Over the past few years, studies have moved from describing phases of chloroplast gene expression to exploring the underlying mechanisms. In this review, we focus on recent advances and emerging principles that govern chloroplast gene expression in land plants. We discuss engineering of pentatricopeptide repeat proteins and its biotechnological effects on chloroplast RNA research; new techniques for characterizing the molecular mechanisms of chloroplast gene expression; and important aspects of chloroplast gene expression for improving crop yield and stress tolerance. We also discuss biological and mechanistic questions that remain to be answered in the future.
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Affiliation(s)
- Yi Zhang
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Lin Tian
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Congming Lu
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China.
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13
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Small I, Melonek J, Bohne AV, Nickelsen J, Schmitz-Linneweber C. Plant organellar RNA maturation. THE PLANT CELL 2023; 35:1727-1751. [PMID: 36807982 PMCID: PMC10226603 DOI: 10.1093/plcell/koad049] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 01/05/2023] [Accepted: 01/17/2023] [Indexed: 05/30/2023]
Abstract
Plant organellar RNA metabolism is run by a multitude of nucleus-encoded RNA-binding proteins (RBPs) that control RNA stability, processing, and degradation. In chloroplasts and mitochondria, these post-transcriptional processes are vital for the production of a small number of essential components of the photosynthetic and respiratory machinery-and consequently for organellar biogenesis and plant survival. Many organellar RBPs have been functionally assigned to individual steps in RNA maturation, often specific to selected transcripts. While the catalog of factors identified is ever-growing, our knowledge of how they achieve their functions mechanistically is far from complete. This review summarizes the current knowledge of plant organellar RNA metabolism taking an RBP-centric approach and focusing on mechanistic aspects of RBP functions and the kinetics of the processes they are involved in.
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Affiliation(s)
- Ian Small
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley 6009, Australia
| | - Joanna Melonek
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley 6009, Australia
| | | | - Jörg Nickelsen
- Department of Molecular Plant Sciences, LMU Munich, 82152 Martinsried, Germany
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14
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Xiong B, Li L, Li Q, Mao H, Wang L, Bie Y, Zeng X, Liao L, Wang X, Deng H, Zhang M, Sun G, Wang Z. Identification of Photosynthesis Characteristics and Chlorophyll Metabolism in Leaves of Citrus Cultivar ( Harumi) with Varying Degrees of Chlorosis. Int J Mol Sci 2023; 24:ijms24098394. [PMID: 37176103 PMCID: PMC10179384 DOI: 10.3390/ijms24098394] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/22/2023] [Accepted: 05/05/2023] [Indexed: 05/15/2023] Open
Abstract
In autumn and spring, citrus leaves with a Ponkan (Citrus reticulata Blanco cv. Ponkan) genetic background (Harumi, Daya, etc.) are prone to abnormal physiological chlorosis. The effects of different degrees of chlorosis (normal, mild, moderate and severe) on photosynthesis and the chlorophyll metabolism of leaves of Citrus cultivar (Harumi) were studied via field experiment. Compared with severe chlorotic leaves, the results showed that chlorosis could break leaf metabolism balance, including reduced chlorophyll content, photosynthetic parameters, antioxidant enzyme activity and enzyme activity related to chlorophyll synthesis, increased catalase and decreased enzyme activity. In addition, the content of chlorophyll synthesis precursors showed an overall downward trend expected for uroporphyrinogen III. Furthermore, the relative expression of genes for chlorophyll synthesis (HEMA1, HEME2, HEMG1 and CHLH) was down-regulated to some extent and chlorophyll degradation (CAO, CLH, PPH, PAO and SGR) showed the opposite trend with increased chlorosis. Changes in degradation were more significant. In general, the chlorosis of Harumi leaves might be related to the blocked transformation of uroporphyrinogen III (Urogen III) to coproporphyrinogen III (Coprogen III), the weakening of antioxidant enzyme system activity, the weakening of chlorophyll synthesis and the enhancement in degradation.
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Affiliation(s)
- Bo Xiong
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Ling Li
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Qin Li
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Huiqiong Mao
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Lixinyi Wang
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Yuhui Bie
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Xin Zeng
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Ling Liao
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Xun Wang
- Institute of Pomology and Olericulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Honghong Deng
- Institute of Pomology and Olericulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Mingfei Zhang
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Guochao Sun
- Institute of Pomology and Olericulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Zhihui Wang
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
- Institute of Pomology and Olericulture, Sichuan Agricultural University, Chengdu 611130, China
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15
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Lee K, Kang H. Engineering of pentatricopeptide repeat proteins in organellar gene regulation. FRONTIERS IN PLANT SCIENCE 2023; 14:1144298. [PMID: 36938060 PMCID: PMC10014608 DOI: 10.3389/fpls.2023.1144298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Affiliation(s)
- Kwanuk Lee
- Department of Biology, Jeju National University, Jeju, Republic of Korea
| | - Hunseung Kang
- Department of Applied Biology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, Republic of Korea
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16
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Legen J, Dühnen S, Gauert A, Götz M, Schmitz-Linneweber C. A CRR2-Dependent sRNA Sequence Supports Papillomavirus Vaccine Expression in Tobacco Chloroplasts. Metabolites 2023; 13:metabo13030315. [PMID: 36984756 PMCID: PMC10054877 DOI: 10.3390/metabo13030315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 02/11/2023] [Accepted: 02/15/2023] [Indexed: 02/24/2023] Open
Abstract
Introduction: Human papillomavirus (HPV) infection is the leading cause of cervical cancer, and vaccination with HPV L1 capsid proteins has been successful in controlling it. However, vaccination coverage is not universal, particularly in developing countries, where 80% of all cervical cancer cases occur. Cost-effective vaccination could be achieved by expressing the L1 protein in plants. Various efforts have been made to produce the L1 protein in plants, including attempts to express it in chloroplasts for high-yield performance. However, manipulating chloroplast gene expression requires complex and difficult-to-control expression elements. In recent years, a family of nuclear-encoded, chloroplast-targeted RNA-binding proteins, the pentatricopeptide repeat (PPR) proteins, were described as key regulators of chloroplast gene expression. For example, PPR proteins are used by plants to stabilize and translate chloroplast mRNAs. Objectives: To demonstrate that a PPR target site can be used to drive HPV L1 expression in chloroplasts. Methods: To test our hypothesis, we used biolistic chloroplast transformation to establish tobacco lines that express two variants of the HPV L1 protein under the control of the target site of the PPR protein CHLORORESPIRATORY REDUCTION2 (CRR2). The transgenes were inserted into a dicistronic operon driven by the plastid rRNA promoter. To determine the effectiveness of the PPR target site for the expression of the HPV L1 protein in the chloroplasts, we analyzed the accumulation of the transgenic mRNA and its processing, as well as the accumulation of the L1 protein in the transgenic lines. Results: We established homoplastomic lines carrying either the HPV18 L1 protein or an HPV16B Enterotoxin::L1 fusion protein. The latter line showed severe growth retardation and pigment loss, suggesting that the fusion protein is toxic to the chloroplasts. Despite the presence of dicistronic mRNAs, we observed very little accumulation of monocistronic transgenic mRNA and no significant increase in CRR2-associated small RNAs. Although both lines expressed the L1 protein, quantification using an external standard suggested that the amounts were low. Conclusions: Our results suggest that PPR binding sites can be used to drive vaccine expression in plant chloroplasts; however, the factors that modulate the effectiveness of target gene expression remain unclear. The identification of dozens of PPR binding sites through small RNA sequencing expands the set of expression elements available for high-value protein production in chloroplasts.
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Affiliation(s)
- Julia Legen
- Molecular Genetics, Humboldt-University Berlin, Philippstr. 13, 10115 Berlin, Germany
| | - Sara Dühnen
- Molecular Genetics, Humboldt-University Berlin, Philippstr. 13, 10115 Berlin, Germany
| | - Anton Gauert
- Molecular Genetics, Humboldt-University Berlin, Philippstr. 13, 10115 Berlin, Germany
| | - Michael Götz
- BioEnergy GmbH, Dietersberg 1, 92334 Berching, Germany
| | - Christian Schmitz-Linneweber
- Molecular Genetics, Humboldt-University Berlin, Philippstr. 13, 10115 Berlin, Germany
- Correspondence: ; Tel.: +49-20-2093-49700
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17
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McDowell R, Small I, Bond CS. Synthetic PPR proteins as tools for sequence-specific targeting of RNA. Methods 2022; 208:19-26. [DOI: 10.1016/j.ymeth.2022.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 09/29/2022] [Accepted: 10/11/2022] [Indexed: 11/06/2022] Open
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18
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An Y, Wang Y, Wang X, Xiao J. Development of chloroplast transformation and gene expression regulation technology in land plants. FRONTIERS IN PLANT SCIENCE 2022; 13:1037038. [PMID: 36407602 PMCID: PMC9667944 DOI: 10.3389/fpls.2022.1037038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 10/07/2022] [Indexed: 06/16/2023]
Abstract
Chloroplasts in land plants have their own small circular DNA that is presumed to have originated from cyanobacteria-related endosymbionts, and the chloroplast genome is an attractive target to improve photosynthetic ability and crop yield. However, to date, most transgenic or genetic engineering technologies for plants are restricted to manipulations of the nuclear genome. In this review, we provide a comprehensive overview of chloroplast genetic engineering and regulation of gene expression from the perspective of history and biology, focusing on current and latest methods. In addition, we suggest techniques that may regulate the chloroplast gene expression at the transcriptional or post-transcriptional level.
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Affiliation(s)
- Yaqi An
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, Beijing Forestry University, Beijing, China
- The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, Beijing Forestry University, Beijing, China
| | - Yue Wang
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, Beijing Forestry University, Beijing, China
- The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, Beijing Forestry University, Beijing, China
| | - Xinwei Wang
- College of Agriculture and Forestry, Hebei North University, Zhangjiakou, China
| | - Jianwei Xiao
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, Beijing Forestry University, Beijing, China
- The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, Beijing Forestry University, Beijing, China
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19
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Hoelscher MP, Forner J, Calderone S, Krämer C, Taylor Z, Loiacono FV, Agrawal S, Karcher D, Moratti F, Kroop X, Bock R. Expression strategies for the efficient synthesis of antimicrobial peptides in plastids. Nat Commun 2022; 13:5856. [PMID: 36195597 PMCID: PMC9532397 DOI: 10.1038/s41467-022-33516-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 09/21/2022] [Indexed: 12/29/2022] Open
Abstract
Antimicrobial peptides (AMPs) kill microbes or inhibit their growth and are promising next-generation antibiotics. Harnessing their full potential as antimicrobial agents will require methods for cost-effective large-scale production and purification. Here, we explore the possibility to exploit the high protein synthesis capacity of the chloroplast to produce AMPs in plants. Generating a large series of 29 sets of transplastomic tobacco plants expressing nine different AMPs as fusion proteins, we show that high-level constitutive AMP expression results in deleterious plant phenotypes. However, by utilizing inducible expression and fusions to the cleavable carrier protein SUMO, the cytotoxic effects of AMPs and fused AMPs are alleviated and plants with wild-type-like phenotypes are obtained. Importantly, purified AMP fusion proteins display antimicrobial activity independently of proteolytic removal of the carrier. Our work provides expression strategies for the synthesis of toxic polypeptides in chloroplasts, and establishes transplastomic plants as efficient production platform for antimicrobial peptides.
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Affiliation(s)
- Matthijs P Hoelscher
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476, Potsdam-Golm, Germany
- Utrecht University, Pharmaceutical sciences, Pharmaceutics, Universiteitsweg 99, 3584 CG, Utrecht, Netherlands
| | - Joachim Forner
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476, Potsdam-Golm, Germany
| | - Silvia Calderone
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476, Potsdam-Golm, Germany
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, Bellaterra, 08193, Barcelona, Spain
| | - Carolin Krämer
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476, Potsdam-Golm, Germany
| | - Zachary Taylor
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476, Potsdam-Golm, Germany
| | - F Vanessa Loiacono
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476, Potsdam-Golm, Germany
| | - Shreya Agrawal
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476, Potsdam-Golm, Germany
- Neoplants, 630 Rue Noetzlin Bâtiment, 91190, Gif-sur-Yvette, France
| | - Daniel Karcher
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476, Potsdam-Golm, Germany
| | - Fabio Moratti
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476, Potsdam-Golm, Germany
| | - Xenia Kroop
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476, Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476, Potsdam-Golm, Germany.
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20
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U-to-C RNA editing by synthetic PPR-DYW proteins in bacteria and human culture cells. Commun Biol 2022; 5:968. [PMID: 36109586 PMCID: PMC9478123 DOI: 10.1038/s42003-022-03927-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 08/31/2022] [Indexed: 11/22/2022] Open
Abstract
Programmable RNA editing offers significant therapeutic potential for a wide range of genetic diseases. Currently, several deaminase enzymes, including ADAR and APOBEC, can perform programmable adenosine-to-inosine or cytidine-to-uridine RNA correction. However, enzymes to perform guanosine-to-adenosine and uridine-to-cytidine (U-to-C) editing are still lacking to complete the set of transition reactions. It is believed that the DYW:KP proteins, specific to seedless plants, catalyze the U-to-C reactions in mitochondria and chloroplasts. In this study, we designed seven DYW:KP domains based on consensus sequences and fused them to a designer RNA-binding pentatricopeptide repeat (PPR) domain. We show that three of these PPR-DYW:KP proteins edit targeted uridine to cytidine in bacteria and human cells. In addition, we show that these proteins have a 5′ but not apparent 3′ preference for neighboring nucleotides. Our results establish the DYW:KP aminase domain as a potential candidate for the development of a U-to-C editing tool in human cells. DYW:KP domains, designed on proteins found in the mitochondria and chloroplasts of seedless plants, are fused to a designer RNA-binding pentatricopeptide repeat (PPR) domain to edit targeted uridine to cytidine in bacteria and human cells.
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21
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Lesch E, Schilling MT, Brenner S, Yang Y, Gruss O, Knoop V, Schallenberg-Rüdinger M. Plant mitochondrial RNA editing factors can perform targeted C-to-U editing of nuclear transcripts in human cells. Nucleic Acids Res 2022; 50:9966-9983. [PMID: 36107771 PMCID: PMC9508816 DOI: 10.1093/nar/gkac752] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 08/10/2022] [Accepted: 08/29/2022] [Indexed: 11/12/2022] Open
Abstract
RNA editing processes are strikingly different in animals and plants. Up to thousands of specific cytidines are converted into uridines in plant chloroplasts and mitochondria whereas up to millions of adenosines are converted into inosines in animal nucleo-cytosolic RNAs. It is unknown whether these two different RNA editing machineries are mutually incompatible. RNA-binding pentatricopeptide repeat (PPR) proteins are the key factors of plant organelle cytidine-to-uridine RNA editing. The complete absence of PPR mediated editing of cytosolic RNAs might be due to a yet unknown barrier that prevents its activity in the cytosol. Here, we transferred two plant mitochondrial PPR-type editing factors into human cell lines to explore whether they could operate in the nucleo-cytosolic environment. PPR56 and PPR65 not only faithfully edited their native, co-transcribed targets but also different sets of off-targets in the human background transcriptome. More than 900 of such off-targets with editing efficiencies up to 91%, largely explained by known PPR-RNA binding properties, were identified for PPR56. Engineering two crucial amino acid positions in its PPR array led to predictable shifts in target recognition. We conclude that plant PPR editing factors can operate in the entirely different genetic environment of the human nucleo-cytosol and can be intentionally re-engineered towards new targets.
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Affiliation(s)
- Elena Lesch
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn , Kirschallee 1 , D-53115 Bonn , Germany
| | - Maximilian T Schilling
- Institut für Genetik, Abteilung Zellteilung, Universität Bonn , Karlrobert-Kreiten-Str. 13 , D-53115 Bonn , Germany
| | - Sarah Brenner
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn , Kirschallee 1 , D-53115 Bonn , Germany
| | - Yingying Yang
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn , Kirschallee 1 , D-53115 Bonn , Germany
| | - Oliver J Gruss
- Institut für Genetik, Abteilung Zellteilung, Universität Bonn , Karlrobert-Kreiten-Str. 13 , D-53115 Bonn , Germany
| | - Volker Knoop
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn , Kirschallee 1 , D-53115 Bonn , Germany
| | - Mareike Schallenberg-Rüdinger
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn , Kirschallee 1 , D-53115 Bonn , Germany
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22
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Yang S, Deng Y, Li S. Advances in plastid transformation for metabolic engineering in higher plants. ABIOTECH 2022; 3:224-232. [PMID: 36313931 PMCID: PMC9590572 DOI: 10.1007/s42994-022-00083-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 09/09/2022] [Indexed: 03/12/2023]
Abstract
The plastid (chloroplast) genome of higher plants is an appealing target for metabolic engineering via genetic transformation. Although the bacterial-type plastid genome is small compared with the nuclear genome, it can accommodate large quantities of foreign genes that precisely integrate through homologous recombination. Engineering complex metabolic pathways in plants often requires simultaneous and concerted expression of multiple transgenes, the possibility of stacking several transgenes in synthetic operons makes the transplastomic approach amazing. The potential for extraordinarily high-level transgene expression, absence of epigenetic gene silencing and transgene containment due to the exclusion of plastids from pollen transmission in most angiosperm species further add to the attractiveness of plastid transformation technology. This minireview describes recent advances in expanding the toolboxes for plastid genome engineering, and highlights selected high-value metabolites produced using transplastomic plants, including artemisinin, astaxanthin and paclitaxel.
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Affiliation(s)
- Sheng Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Yi Deng
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Shengchun Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062 China
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23
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Sugita M. An Overview of Pentatricopeptide Repeat (PPR) Proteins in the Moss Physcomitrium patens and Their Role in Organellar Gene Expression. PLANTS 2022; 11:plants11172279. [PMID: 36079663 PMCID: PMC9459714 DOI: 10.3390/plants11172279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 08/29/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022]
Abstract
Pentatricopeptide repeat (PPR) proteins are one type of helical repeat protein that are widespread in eukaryotes. In particular, there are several hundred PPR members in flowering plants. The majority of PPR proteins are localized in the plastids and mitochondria, where they play a crucial role in various aspects of RNA metabolism at the post-transcriptional and translational steps during gene expression. Among the early land plants, the moss Physcomitrium (formerly Physcomitrella) patens has at least 107 PPR protein-encoding genes, but most of their functions remain unclear. To elucidate the functions of PPR proteins, a reverse-genetics approach has been applied to P. patens. To date, the molecular functions of 22 PPR proteins were identified as essential factors required for either mRNA processing and stabilization, RNA splicing, or RNA editing. This review examines the P. patens PPR gene family and their current functional characterization. Similarities and a diversity of functions of PPR proteins between P. patens and flowering plants and their roles in the post-transcriptional regulation of organellar gene expression are discussed.
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Affiliation(s)
- Mamoru Sugita
- Graduate School of Informatics, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
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Bock R. Transplastomic approaches for metabolic engineering. CURRENT OPINION IN PLANT BIOLOGY 2022; 66:102185. [PMID: 35183927 DOI: 10.1016/j.pbi.2022.102185] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 06/14/2023]
Abstract
The plastid (chloroplast) genome of seed plants represents an attractive target of metabolic pathway engineering by genetic transformation. Although the plastid genome is relatively small, it can accommodate large amounts of foreign DNA that precisely integrates via homologous recombination, and is largely excluded from pollen transmission due to the maternal mode of plastid inheritance. Since the engineering of metabolic pathways often requires the expression of multiple transgenes, the possibility to conveniently stack transgenes in synthetic operons makes the transplastomic technology particularly appealing in the area of metabolic engineering. Absence of epigenetic gene silencing mechanisms from plastids and the possibility to achieve high transgene expression levels further add to the attractiveness of plastid genome transformation. This review focuses on engineering principles and available tools for the transplastomic expression of enzymes and pathways, and highlights selected recent applications in metabolic engineering.
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Affiliation(s)
- Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany.
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25
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Shahar N, Elman T, Williams-Carrier R, Ben-Zvi O, Yacoby I, Barkan A. Use of plant chloroplast RNA-binding proteins as orthogonal activators of chloroplast transgenes in the green alga Chlamydomonas reinhardtii. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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26
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Huang D, Kosentka PZ, Liu W. Synthetic biology approaches in regulation of targeted gene expression. CURRENT OPINION IN PLANT BIOLOGY 2021; 63:102036. [PMID: 33930839 DOI: 10.1016/j.pbi.2021.102036] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 05/15/2023]
Abstract
Synthetic biology approaches are highly sought-after to facilitate the regulation of targeted gene expression in plants for functional genomics research and crop trait improvement. To date, synthetic regulation of gene expression predominantly focuses at the transcription level via engineering of synthetic promoters and transcription factors, while pioneering examples have started to emerge for synthetic regulation of gene expression at the levels of mRNA stability, translation, and protein degradation. This review discusses recent advances in plant synthetic biology for the regulation of gene expression at multiple levels, and highlights their future directions.
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Affiliation(s)
- Debao Huang
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27607, USA
| | - Pawel Z Kosentka
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27607, USA
| | - Wusheng Liu
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27607, USA.
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The radish Ogura fertility restorer impedes translation elongation along its cognate CMS-causing mRNA. Proc Natl Acad Sci U S A 2021; 118:2105274118. [PMID: 34433671 DOI: 10.1073/pnas.2105274118] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The control of messenger RNA (mRNA) translation has been increasingly recognized as a key regulatory step for gene control, but clear examples in eukaryotes are still scarce. Nucleo-cytoplasmic male sterilities (CMS) represent ideal genetic models to dissect genetic interactions between the mitochondria and the nucleus in plants. This trait is determined by specific mitochondrial genes and is associated with a pollen sterility phenotype that can be suppressed by nuclear genes known as restorer-of-fertility (Rf). In this study, we focused on the Ogura CMS system in rapeseed and showed that reversion to male sterility by the PPR-B fertility restorer (also called Rfo) occurs through a specific translation inhibition of the mitochondria-encoded CMS-causing mRNA orf138 We also demonstrate that PPR-B binds within the coding sequence of orf138 and acts as a ribosome blocker to specifically impede translation elongation along the orf138 mRNA. Rfo is the first recognized fertility restorer shown to act this way. These observations will certainly facilitate the development of synthetic fertility restorers for CMS systems in which efficient natural Rfs are lacking.
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Larrea-Álvarez M, Purton S. The Chloroplast of Chlamydomonas reinhardtii as a Testbed for Engineering Nitrogen Fixation into Plants. Int J Mol Sci 2021; 22:8806. [PMID: 34445505 PMCID: PMC8395883 DOI: 10.3390/ijms22168806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 08/05/2021] [Accepted: 08/10/2021] [Indexed: 12/27/2022] Open
Abstract
Eukaryotic organisms such as plants are unable to utilise nitrogen gas (N2) directly as a source of this essential element and are dependent either on its biological conversion to ammonium by diazotrophic prokaryotes, or its supply as chemically synthesised nitrate fertiliser. The idea of genetically engineering crops with the capacity to fix N2 by introduction of the bacterial nitrogenase enzyme has long been discussed. However, the expression of an active nitrogenase must overcome several major challenges: the coordinated expression of multiple genes to assemble an enzyme complex containing several different metal cluster co-factors; the supply of sufficient ATP and reductant to the enzyme; the enzyme's sensitivity to oxygen; and the intracellular accumulation of ammonium. The chloroplast of plant cells represents an attractive location for nitrogenase expression, but engineering the organelle's genome is not yet feasible in most crop species. However, the unicellular green alga Chlamydomonas reinhardtii represents a simple model for photosynthetic eukaryotes with a genetically tractable chloroplast. In this review, we discuss the main advantages, and limitations, of this microalga as a testbed for producing such a complex multi-subunit enzyme. Furthermore, we suggest that a minimal set of six transgenes are necessary for chloroplast-localised synthesis of an 'Fe-only' nitrogenase, and from this set we demonstrate the stable expression and accumulation of the homocitrate synthase, NifV, under aerobic conditions. Arguably, further studies in C. reinhardtii aimed at testing expression and function of the full gene set would provide the groundwork for a concerted future effort to create nitrogen-fixing crops.
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Affiliation(s)
- Marco Larrea-Álvarez
- School of Biological Sciences and Engineering, Yachay-Tech University Hacienda San José, Urcuquí-Imbabura 100650, Ecuador;
- Algal Research Group, Department of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Saul Purton
- Algal Research Group, Department of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK
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Frangedakis E, Guzman-Chavez F, Rebmann M, Markel K, Yu Y, Perraki A, Tse SW, Liu Y, Rever J, Sauret-Gueto S, Goffinet B, Schneider H, Haseloff J. Construction of DNA Tools for Hyperexpression in Marchantia Chloroplasts. ACS Synth Biol 2021; 10:1651-1666. [PMID: 34097383 PMCID: PMC8296666 DOI: 10.1021/acssynbio.0c00637] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Chloroplasts are attractive platforms for synthetic biology applications since they are capable of driving very high levels of transgene expression, if mRNA production and stability are properly regulated. However, plastid transformation is a slow process and currently limited to a few plant species. The liverwort Marchantia polymorpha is a simple model plant that allows rapid transformation studies; however, its potential for protein hyperexpression has not been fully exploited. This is partially due to the fact that chloroplast post-transcriptional regulation is poorly characterized in this plant. We have mapped patterns of transcription in Marchantia chloroplasts. Furthermore, we have obtained and compared sequences from 51 bryophyte species and identified putative sites for pentatricopeptide repeat protein binding that are thought to play important roles in mRNA stabilization. Candidate binding sites were tested for their ability to confer high levels of reporter gene expression in Marchantia chloroplasts, and levels of protein production and effects on growth were measured in homoplastic transformed plants. We have produced novel DNA tools for protein hyperexpression in this facile plant system that is a test-bed for chloroplast engineering.
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Affiliation(s)
- Eftychios Frangedakis
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Fernando Guzman-Chavez
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Marius Rebmann
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Kasey Markel
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Ying Yu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China
| | - Artemis Perraki
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Sze Wai Tse
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Yang Liu
- Fairy Lake Botanical Garden & Chinese Academy of Sciences, Shenzhen, Guangdong 518004, China
| | - Jenna Rever
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Susanna Sauret-Gueto
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Bernard Goffinet
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut 06269-3043, United States
| | - Harald Schneider
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan 666303, China
| | - Jim Haseloff
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
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30
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Manavski N, Mathieu S, Rojas M, Méteignier LV, Brachmann A, Barkan A, Hammani K. In vivo stabilization of endogenous chloroplast RNAs by customized artificial pentatricopeptide repeat proteins. Nucleic Acids Res 2021; 49:5985-5997. [PMID: 34037778 PMCID: PMC8191804 DOI: 10.1093/nar/gkab390] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 04/05/2021] [Accepted: 04/28/2021] [Indexed: 12/17/2022] Open
Abstract
Pentatricopeptide repeat (PPR) proteins are helical repeat-proteins that bind RNA in a modular fashion with a sequence-specificity that can be manipulated by the use of an amino acid code. As such, PPR repeats are promising scaffolds for the design of RNA binding proteins for synthetic biology applications. However, the in vivo functional capabilities of artificial PPR proteins built from consensus PPR motifs are just starting to be explored. Here, we report in vivo functions of an artificial PPR protein, dPPRrbcL, made of consensus PPR motifs that were designed to bind a sequence near the 5′ end of rbcL transcripts in Arabidopsis chloroplasts. We used a functional complementation assay to demonstrate that this protein bound its intended RNA target with specificity in vivo and that it substituted for a natural PPR protein by stabilizing processed rbcL mRNA. We targeted a second protein of analogous design to the petL 5′ UTR, where it substituted for the native stabilizing PPR protein PGR3, albeit inefficiently. These results showed that artificial PPR proteins can be engineered to functionally mimic the class of native PPR proteins that serve as physical barriers against exoribonucleases.
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Affiliation(s)
- Nikolay Manavski
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
| | - Sébastien Mathieu
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
| | - Margarita Rojas
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403 USA
| | - Louis-Valentin Méteignier
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
| | - Andreas Brachmann
- Genetics, Faculty of Biology, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried Germany
| | - Alice Barkan
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403 USA
| | - Kamel Hammani
- To whom correspondence should be addressed. Tel: +33 367155281; Fax: +33 367155300;
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Wang H, Xiao Q, Wei C, Chen H, Chen X, Dai C, Wen J, Ma C, Tu J, Fu T, Shen J, Yi B. A mitochondria-localized pentatricopeptide repeat protein is required to restore hau cytoplasmic male sterility in Brassica napus. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2021; 134:1377-1386. [PMID: 33725137 DOI: 10.1007/s00122-021-03777-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 01/16/2021] [Indexed: 06/12/2023]
Abstract
A mitochondria-localized pentatricopeptide repeat protein was identified by positional cloning and transferred into the hau CMS line, where it successfully restored fertility Cytoplasmic male sterility (CMS) is a maternally inherited trait that can be controlled by restorer-of-fertility (Rf) genes present in the nucleus. The hau CMS was identified as a new form of CMS associated with the mitochondrial transcript orf288; however, a lack of a restorer gene has limited its utilization in Brassica crops. Here, the combination of Brassica 60 K array with bulk segregant analysis and map-based cloning was used to delimit the Rfh locus to an 82.2-kb region on chromosome A09. A candidate gene encoding a mitochondria-localized pentatricopeptide repeat (PPR) protein was identified and transferred into the hau CMS line, where it successfully restored the fertility of the hau CMS plants. Furthermore, the expression analysis showed that Rfh was highly expressed in the flower buds, and the sequence analysis results implied that functional divergence between RFH and rfh could be due to 59 amino acid residue differences in the deduced protein sequences. In addition, a co-separated molecular marker was developed based on the divergent sequences between the dominant and recessive alleles. These results will help enable the heterosis of Brassica crops in the future.
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Affiliation(s)
- Huadong Wang
- National Key Laboratory of Crop Genetic Improvement, National Centre of Rapeseed Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Qing Xiao
- National Key Laboratory of Crop Genetic Improvement, National Centre of Rapeseed Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Chao Wei
- National Key Laboratory of Crop Genetic Improvement, National Centre of Rapeseed Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
- College of Life Science, Zhaoqing University, Zhaoqing, 526061, People's Republic of China
| | - Hui Chen
- National Key Laboratory of Crop Genetic Improvement, National Centre of Rapeseed Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Xiaohan Chen
- National Key Laboratory of Crop Genetic Improvement, National Centre of Rapeseed Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Cheng Dai
- National Key Laboratory of Crop Genetic Improvement, National Centre of Rapeseed Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Jing Wen
- National Key Laboratory of Crop Genetic Improvement, National Centre of Rapeseed Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Chaozhi Ma
- National Key Laboratory of Crop Genetic Improvement, National Centre of Rapeseed Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Jinxing Tu
- National Key Laboratory of Crop Genetic Improvement, National Centre of Rapeseed Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Tingdong Fu
- National Key Laboratory of Crop Genetic Improvement, National Centre of Rapeseed Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Jinxiong Shen
- National Key Laboratory of Crop Genetic Improvement, National Centre of Rapeseed Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
| | - Bin Yi
- National Key Laboratory of Crop Genetic Improvement, National Centre of Rapeseed Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
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Li S, Chang L, Zhang J. Advancing organelle genome transformation and editing for crop improvement. PLANT COMMUNICATIONS 2021; 2:100141. [PMID: 33898977 PMCID: PMC8060728 DOI: 10.1016/j.xplc.2021.100141] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 12/15/2020] [Accepted: 01/01/2021] [Indexed: 05/05/2023]
Abstract
Plant cells contain three organelles that harbor DNA: the nucleus, plastids, and mitochondria. Plastid transformation has emerged as an attractive platform for the generation of transgenic plants, also referred to as transplastomic plants. Plastid genomes have been genetically engineered to improve crop yield, nutritional quality, and resistance to abiotic and biotic stresses, as well as for recombinant protein production. Despite many promising proof-of-concept applications, transplastomic plants have not been commercialized to date. Sequence-specific nuclease technologies are widely used to precisely modify nuclear genomes, but these tools have not been applied to edit organelle genomes because the efficient homologous recombination system in plastids facilitates plastid genome editing. Unlike plastid transformation, successful genetic transformation of higher plant mitochondrial genome transformation was tested in several research group, but not successful to date. However, stepwise progress has been made in modifying mitochondrial genes and their transcripts, thus enabling the study of their functions. Here, we provide an overview of advances in organelle transformation and genome editing for crop improvement, and we discuss the bottlenecks and future development of these technologies.
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Affiliation(s)
- Shengchun Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Ling Chang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Jiang Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China
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Macedo-Osorio KS, Martínez-Antonio A, Badillo-Corona JA. Pas de Trois: An Overview of Penta-, Tetra-, and Octo-Tricopeptide Repeat Proteins From Chlamydomonas reinhardtii and Their Role in Chloroplast Gene Expression. FRONTIERS IN PLANT SCIENCE 2021; 12:775366. [PMID: 34868174 PMCID: PMC8635915 DOI: 10.3389/fpls.2021.775366] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 10/26/2021] [Indexed: 05/05/2023]
Abstract
Penta-, Tetra-, and Octo-tricopeptide repeat (PPR, TPR, and OPR) proteins are nucleus-encoded proteins composed of tandem repeats of 35, 34, and 38-40 amino acids, respectively. They form helix-turn-helix structures that interact with mRNA or other proteins and participate in RNA stabilization, processing, maturation, and act as translation enhancers of chloroplast and mitochondrial mRNAs. These helical repeat proteins are unevenly present in plants and algae. While PPR proteins are more abundant in plants than in algae, OPR proteins are more abundant in algae. In Arabidopsis, maize, and rice there have been 450, 661, and 477 PPR proteins identified, respectively, which contrasts with only 14 PPR proteins identified in Chlamydomonas reinhardtii. Likewise, more than 120 OPR proteins members have been predicted from the nuclear genome of C. reinhardtii and only one has been identified in Arabidopsis thaliana. Due to their abundance in land plants, PPR proteins have been largely characterized making it possible to elucidate their RNA-binding code. This has even allowed researchers to generate engineered PPR proteins with defined affinity to a particular target, which has served as the basis to develop tools for gene expression in biotechnological applications. However, fine elucidation of the helical repeat proteins code in Chlamydomonas is a pending task. In this review, we summarize the current knowledge on the role PPR, TPR, and OPR proteins play in chloroplast gene expression in the green algae C. reinhardtii, pointing to relevant similarities and differences with their counterparts in plants. We also recapitulate on how these proteins have been engineered and shown to serve as mRNA regulatory factors for biotechnological applications in plants and how this could be used as a starting point for applications in algae.
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Affiliation(s)
- Karla S. Macedo-Osorio
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, México City, México
- Biological Engineering Laboratory, Genetic Engineering Department, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional-Unidad Irapuato, Irapuato, México
- División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana-Xochimilco, México City, México
- *Correspondence: Karla S. Macedo-Osorio,
| | - Agustino Martínez-Antonio
- Biological Engineering Laboratory, Genetic Engineering Department, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional-Unidad Irapuato, Irapuato, México
| | - Jesús A. Badillo-Corona
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, México City, México
- Jesús A. Badillo-Corona,
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Breman FC, Snijder RC, Korver JW, Pelzer S, Sancho-Such M, Schranz ME, Bakker FT. Interspecific Hybrids Between Pelargonium × hortorum and Species From P. Section Ciconium Reveal Biparental Plastid Inheritance and Multi-Locus Cyto-Nuclear Incompatibility. FRONTIERS IN PLANT SCIENCE 2020; 11:614871. [PMID: 33391328 PMCID: PMC7775418 DOI: 10.3389/fpls.2020.614871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/23/2020] [Indexed: 06/01/2023]
Abstract
The genetics underlying Cyto-Nuclear Incompatibility (CNI) was studied in Pelargonium interspecific hybrids. We created hybrids of 12 closely related crop wild relatives (CWR) with the ornamental P. × hortorum. Ten of the resulting 12 (F1) interspecific hybrids segregate for chlorosis suggesting biparental plastid inheritance. The segregation ratios of the interspecific F2 populations show nuclear interactions of one, two, or three nuclear genes regulating plastid function dependent on the parents. We further validated that biparental inheritance of plastids is common in section Ciconium, using diagnostic PCR primers. Our results pave the way for using the diverse species from section Ciconium, each with its own set of characteristics, as novel sources of desired breeding traits for P. × hortorum cultivars.
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Affiliation(s)
- Floris C. Breman
- Biosystematics Group, Wageningen University and Research, Wageningen, Netherlands
| | | | - Joost W. Korver
- Biosystematics Group, Wageningen University and Research, Wageningen, Netherlands
| | - Sieme Pelzer
- Biosystematics Group, Wageningen University and Research, Wageningen, Netherlands
| | | | - M. Eric Schranz
- Biosystematics Group, Wageningen University and Research, Wageningen, Netherlands
| | - Freek T. Bakker
- Biosystematics Group, Wageningen University and Research, Wageningen, Netherlands
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35
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Yu Q, Tungsuchat-Huang T, Verma K, Radler MR, Maliga P. Independent translation of ORFs in dicistronic operons, synthetic building blocks for polycistronic chloroplast gene expression. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:2318-2329. [PMID: 32497322 DOI: 10.1111/tpj.14864] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 05/13/2020] [Accepted: 05/21/2020] [Indexed: 06/11/2023]
Abstract
We designed a dicistronic plastid marker system that relies on the plastid's ability to translate polycistronic mRNAs. The identification of transplastomic clones is based on selection for antibiotic resistance encoded in the first open reading frame (ORF) and accumulation of the reporter gene product in tobacco chloroplasts encoded in the second ORF. The antibiotic resistance gene may encode spectinomycin or kanamycin resistance based on the expression of aadA or neo genes, respectively. The reporter gene used in the study is the green fluorescent protein (GFP). The mRNA level depends on the 5'-untranslated region of the first ORF. The protein output depends on the strengths of the ribosome binding, and is proportional with the level of translatable mRNA. Because the dicistronic mRNA is not processed, we could show that protein output from the second ORF is independent from the first ORF. High-level GFP accumulation from the second ORF facilitates identification of transplastomic events under ultraviolet light. Expression of multiple proteins from an unprocessed mRNA is an experimental design that enables predictable protein output from polycistronic mRNAs, expanding the toolkit of plant synthetic biology.
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Affiliation(s)
- Qiguo Yu
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
| | | | - Kanak Verma
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
| | - Megan R Radler
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
| | - Pal Maliga
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, 08901, USA
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Carrera-Pacheco SE, Hankamer B, Oey M. Light and heat-shock mediated TDA1 overexpression as a tool for controlled high-yield recombinant protein production in Chlamydomonas reinhardtii chloroplasts. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.101921] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Zhang X, Gu C, Zhang T, Tong B, Zhang H, Wu Y, Yang C. Chloroplast (Cp) Transcriptome of P. davidiana Dode×P. bolleana Lauch provides insight into the Cp drought response and Populus Cp phylogeny. BMC Evol Biol 2020; 20:51. [PMID: 32375634 PMCID: PMC7201580 DOI: 10.1186/s12862-020-01622-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 04/29/2020] [Indexed: 02/06/2023] Open
Abstract
Background Raw second-generation (2G) lignocellulosic biomass materials have the potential for development into a sustainable and renewable source of energy. Poplar is regarded as a promising 2G material (P. davidiana Dode×P. bolleana Lauch, P. bolleana, P. davidiana, P. euphratica, et al). However, their large-scale commercialization still faces many obstacles. For example, drought prevents sufficient irrigation or rainfall, which can reduce soil moisture and eventually destroy the chloroplast, the plant photosynthetic organelle. Heterosis is widely used in the production of drought-tolerant materials, such as the superior clone “Shanxinyang” selected from the offspring of Populus davidiana Dode×Populus bolleana Lauch. Because it produces good wood and is easily genetically transformed, “Shanxinyang” has become a promising material for use in tree genetics. It is also one of the most abundant biofuel plants in northern China. Understanding the genetic features of chloroplasts, the cp transcriptome and physiology is crucial to elucidating the chloroplast drought-response model. Results In this study, the whole genome of “Shanxinyang” was sequenced. The chloroplast genome was assembled, and chloroplast structure was analysed and compared with that of other popular plants. Chloroplast transcriptome analysis was performed under drought conditions. The total length of the “Shanxinyang” chloroplast genome was 156,190 bp, the GC content was 36.75%, and the genome was composed of four typical areas (LSC, IRa, IRb, and SSC). A total of 114 simple repeats were detected in the chloroplast genome of “Shanxinyang”. In cp transcriptome analysis, we found 161 up-regulated and 157 down-regulated genes under drought, and 9 cpDEGs was randomly selected to conduct reverse transcription (RT)–qPCR., in which the Log2 (fold change) was significantly consistent with the qPCR results. The analysis of chloroplast transcription under drought provided clues for understanding chloroplast function under drought. The phylogenetic position of “Shanxinyang” within Populus was analysed by using the chloroplast genome sequences of 23 Populus plants, showing that “Shanxinyang” belongs to Sect. Populus and is sister to Populus davidiana. Further, mVISTA analysis showed that the variation in non-coding (regulatory) regions was greater than that in coding regions, which suggests that further attention should be paid to the chloroplast in order to obtain new evolutionary or functional insights related to aspects of plant biology. Conclusions Our findings indicate that complex prokaryotic genome regulation occurs when processing transcripts under drought stress. The results not only offer clues for understanding the chloroplast genome and transcription features in woody plants but also serve as a basis for future molecular studies on poplar species.
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Affiliation(s)
- Xin Zhang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China.,School of Forestry, Shenyang Agricultural University, 120 Dongling Road, Shenyang, 10866, China
| | - Chenrui Gu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China
| | - Tianxu Zhang
- College of Life Science, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China
| | - Botong Tong
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China
| | - Heng Zhang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China
| | - Yueliang Wu
- School of Forestry, Shenyang Agricultural University, 120 Dongling Road, Shenyang, 10866, China
| | - Chuanping Yang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China.
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Matsuda T, Sugita M, Ichinose M. The L motifs of two moss pentatricopeptide repeat proteins are involved in RNA editing but predominantly not in RNA recognition. PLoS One 2020; 15:e0232366. [PMID: 32348368 PMCID: PMC7190159 DOI: 10.1371/journal.pone.0232366] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 04/13/2020] [Indexed: 11/18/2022] Open
Abstract
Pentatricopeptide repeat (PPR) proteins, composed of PPR motifs repeated in tandem, are sequence-specific RNA binding proteins. Recent bioinformatic studies have shown that the combination of polar amino acids at positions 5 and last in each PPR motif recognizes RNA bases, and an RNA recognition code for PPR proteins has been proposed. Subsequent studies confirmed that the P (canonical length) and S (short) motifs bind to specific nucleotides according to this code. However, the contribution of L (long) motifs to RNA recognition is mostly controversial, owing to the presence of a nonpolar amino acid at position 5. The PLS-class PPR protein PpPPR_56 is a mitochondrial RNA editing factor in the moss Physcomitrella patens. Here, we performed in vitro RNA binding and in vivo complementation assays with PpPPR_56 and its variants containing mutated L motifs to investigate their contributions to RNA recognition. In vitro RNA binding assay showed that the original combination of amino acids at positions 5 and last in the L motifs of PpPPR_56 is not required for RNA recognition. In addition, an in vivo complementation assay with RNA editing factors PpPPR_56 and PpPPR_78 revealed the importance of nonpolar amino acids at position 5 of C-terminal L motifs for efficient RNA editing. Our findings suggest that L motifs function as non-binding spacers, not as RNA-binding motifs, to facilitate the formation of a complex between PLS-class PPR protein and RNA. As a result, the DYW domain, a putative catalytic deaminase responsible for C-to-U RNA editing, is correctly placed in proximity to C, which is to be edited.
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Affiliation(s)
- Takuya Matsuda
- Center for Gene Research, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Mamoru Sugita
- Center for Gene Research, Nagoya University, Chikusa-ku, Nagoya, Japan
- * E-mail: (MI); (MS)
| | - Mizuho Ichinose
- Center for Gene Research, Nagoya University, Chikusa-ku, Nagoya, Japan
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa-ku, Nagoya, Japan
- * E-mail: (MI); (MS)
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Small ID, Schallenberg-Rüdinger M, Takenaka M, Mireau H, Ostersetzer-Biran O. Plant organellar RNA editing: what 30 years of research has revealed. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:1040-1056. [PMID: 31630458 DOI: 10.1111/tpj.14578] [Citation(s) in RCA: 181] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 09/25/2019] [Accepted: 10/08/2019] [Indexed: 05/21/2023]
Abstract
The central dogma in biology defines the flow of genetic information from DNA to RNA to protein. Accordingly, RNA molecules generally accurately follow the sequences of the genes from which they are transcribed. This rule is transgressed by RNA editing, which creates RNA products that differ from their DNA templates. Analyses of the RNA landscapes of terrestrial plants have indicated that RNA editing (in the form of C-U base transitions) is highly prevalent within organelles (that is, mitochondria and chloroplasts). Numerous C→U conversions (and in some plants also U→C) alter the coding sequences of many of the organellar transcripts and can also produce translatable mRNAs by creating AUG start sites or eliminating premature stop codons, or affect the RNA structure, influence splicing and alter the stability of RNAs. RNA-binding proteins are at the heart of post-transcriptional RNA expression. The C-to-U RNA editing process in plant mitochondria involves numerous nuclear-encoded factors, many of which have been identified as pentatricopeptide repeat (PPR) proteins that target editing sites in a sequence-specific manner. In this review we report on major discoveries on RNA editing in plant organelles, since it was first documented 30 years ago.
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Affiliation(s)
- Ian D Small
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, WA, 6009, Australia
| | - Mareike Schallenberg-Rüdinger
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abt. Molekulare Evolution, University of Bonn, Kirschallee 1, 53115, Bonn, Germany
| | - Mizuki Takenaka
- Department of Botany, Graduate School of Science, Kyoto University, Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Hakim Mireau
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78026, Versailles Cedex, France
| | - Oren Ostersetzer-Biran
- Department of Plant and Environmental Sciences, Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus - Givat Ram, Jerusalem, 9190401, Israel
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Gutmann B, Royan S, Schallenberg-Rüdinger M, Lenz H, Castleden IR, McDowell R, Vacher MA, Tonti-Filippini J, Bond CS, Knoop V, Small ID. The Expansion and Diversification of Pentatricopeptide Repeat RNA-Editing Factors in Plants. MOLECULAR PLANT 2020; 13:215-230. [PMID: 31760160 DOI: 10.1016/j.molp.2019.11.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 10/10/2019] [Accepted: 11/11/2019] [Indexed: 05/08/2023]
Abstract
The RNA-binding pentatricopeptide repeat (PPR) family comprises hundreds to thousands of genes in most plants, but only a few dozen in algae, indicating massive gene expansions during land plant evolution. The nature and timing of these expansions has not been well defined due to the sparse sequence data available from early-diverging land plant lineages. In this study, we exploit the comprehensive OneKP datasets of over 1000 transcriptomes from diverse plants and algae toward establishing a clear picture of the evolution of this massive gene family, focusing on the proteins typically associated with RNA editing, which show the most spectacular variation in numbers and domain composition across the plant kingdom. We characterize over 2 250 000 PPR motifs in over 400 000 proteins. In lycophytes, polypod ferns, and hornworts, nearly 10% of expressed protein-coding genes encode putative PPR editing factors, whereas they are absent from algae and complex-thalloid liverworts. We show that rather than a single expansion, most land plant lineages with high numbers of editing factors have continued to generate novel sequence diversity. We identify sequence variations that imply functional differences between PPR proteins in seed plants versus non-seed plants and variations we propose to be linked to seed-plant-specific editing co-factors. Finally, using the sequence variations across the datasets, we develop a structural model of the catalytic DYW domain associated with C-to-U editing and identify a clade of unique DYW variants that are strong candidates as U-to-C RNA-editing factors, given their phylogenetic distribution and sequence characteristics.
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Affiliation(s)
- Bernard Gutmann
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Perth 6009, WA, Australia; School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, WA, Australia
| | - Santana Royan
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Perth 6009, WA, Australia; School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, WA, Australia
| | - Mareike Schallenberg-Rüdinger
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Henning Lenz
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Ian R Castleden
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Perth 6009, WA, Australia; School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, WA, Australia
| | - Rose McDowell
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Perth 6009, WA, Australia; School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, WA, Australia
| | - Michael A Vacher
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Perth 6009, WA, Australia; School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, WA, Australia
| | - Julian Tonti-Filippini
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Perth 6009, WA, Australia; School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, WA, Australia
| | - Charles S Bond
- School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, WA, Australia
| | - Volker Knoop
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Ian D Small
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Perth 6009, WA, Australia; School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, WA, Australia.
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Yu Q, Barkan A, Maliga P. Engineered RNA-binding protein for transgene activation in non-green plastids. NATURE PLANTS 2019; 5:486-490. [PMID: 31036913 DOI: 10.1038/s41477-019-0413-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 03/22/2019] [Indexed: 06/09/2023]
Abstract
Non-green plastids are desirable for the expression of recombinant proteins in edible plant parts to enhance the nutritional value of tubers or fruits, or to deliver pharmaceuticals. However, plastid transgenes are expressed at extremely low levels in the amyloplasts of storage organs such as tubers1-3. Here, we report a regulatory system comprising a variant of the maize RNA-binding protein PPR10 and a cognate binding site upstream of a plastid transgene that encodes green fluorescent protein (GFP). The binding site is not recognized by the resident potato PPR10 protein, restricting GFP protein accumulation to low levels in leaves. When the PPR10 variant is expressed from the tuber-specific patatin promoter, GFP accumulates up to 1.3% of the total soluble protein, a 60-fold increase compared with previous studies2 (0.02%). This regulatory system enables an increase in transgene expression in non-photosynthetic plastids without interfering with chloroplast gene expression in leaves.
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Affiliation(s)
- Qiguo Yu
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, USA
| | - Alice Barkan
- Institute of Molecular Biology, University of Oregon, Eugene, OR, USA
| | - Pal Maliga
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, USA.
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, USA.
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Quétier F. Building biofactories with PPR10s. NATURE PLANTS 2019; 5:453-454. [PMID: 31040445 DOI: 10.1038/s41477-019-0426-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Affiliation(s)
- Francis Quétier
- Biology Department, Paris-Saclay University, Evry, France.
- GIP-Genopole, Evry, France.
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