1
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Gorjifard S, Jores T, Tonnies J, Mueth NA, Bubb K, Wrightsman T, Buckler ES, Fields S, Cuperus JT, Queitsch C. Arabidopsis and maize terminator strength is determined by GC content, polyadenylation motifs and cleavage probability. Nat Commun 2024; 15:5868. [PMID: 38997252 PMCID: PMC11245536 DOI: 10.1038/s41467-024-50174-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 07/03/2024] [Indexed: 07/14/2024] Open
Abstract
The 3' end of a gene, often called a terminator, modulates mRNA stability, localization, translation, and polyadenylation. Here, we adapted Plant STARR-seq, a massively parallel reporter assay, to measure the activity of over 50,000 terminators from the plants Arabidopsis thaliana and Zea mays. We characterize thousands of plant terminators, including many that outperform bacterial terminators commonly used in plants. Terminator activity is species-specific, differing in tobacco leaf and maize protoplast assays. While recapitulating known biology, our results reveal the relative contributions of polyadenylation motifs to terminator strength. We built a computational model to predict terminator strength and used it to conduct in silico evolution that generated optimized synthetic terminators. Additionally, we discover alternative polyadenylation sites across tens of thousands of terminators; however, the strongest terminators tend to have a dominant cleavage site. Our results establish features of plant terminator function and identify strong naturally occurring and synthetic terminators.
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Affiliation(s)
- Sayeh Gorjifard
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA
| | - Tobias Jores
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA
| | - Jackson Tonnies
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA
- Graduate Program in Biology, University of Washington, Seattle, WA, 98195, USA
| | - Nicholas A Mueth
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA
| | - Kerry Bubb
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA
| | - Travis Wrightsman
- Section of Plant Breeding and Genetics, Cornell University, Ithaca, NY, 14853, USA
| | - Edward S Buckler
- Section of Plant Breeding and Genetics, Cornell University, Ithaca, NY, 14853, USA
- Agricultural Research Service, United States Department of Agriculture, Ithaca, NY, 14853, USA
- Institute for Genomic Diversity, Cornell University, Ithaca, NY, 14853, USA
| | - Stanley Fields
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA
- Department of Medicine, University of Washington, Seattle, WA, 98195, USA
| | - Josh T Cuperus
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA
| | - Christine Queitsch
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA.
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2
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Nazarian-Firouzabadi F, Torres MDT, de la Fuente-Nunez C. Recombinant production of antimicrobial peptides in plants. Biotechnol Adv 2024; 71:108296. [PMID: 38042311 DOI: 10.1016/j.biotechadv.2023.108296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/10/2023] [Accepted: 11/26/2023] [Indexed: 12/04/2023]
Abstract
Classical plant breeding methods are limited in their ability to confer disease resistance on plants. However, in recent years, advancements in molecular breeding and biotechnological have provided new approaches to overcome these limitations and protect plants from disease. Antimicrobial peptides (AMPs) constitute promising agents that may be able to protect against infectious agents. Recently, peptides have been recombinantly produced in plants at scale and low cost. Because AMPs are less likely than conventional antimicrobials to elicit resistance of pathogenic bacteria, they open up exciting new avenues for agricultural applications. Here, we review recent advances in the design and production of bioactive recombinant AMPs that can effectively protect crop plants from diseases.
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Affiliation(s)
- Farhad Nazarian-Firouzabadi
- Production Engineering and Plant Genetics Department, Faculty of Agriculture, Lorestan University, P.O. Box, 465, Khorramabad, Iran.
| | - Marcelo Der Torossian Torres
- Machine Biology Group, Departments of Psychiatry and Microbiology, Institute for Biomedical Informatics, Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America; Departments of Bioengineering and Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, United States of America; Penn Institute for Computational Science, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Cesar de la Fuente-Nunez
- Machine Biology Group, Departments of Psychiatry and Microbiology, Institute for Biomedical Informatics, Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America; Departments of Bioengineering and Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, United States of America; Penn Institute for Computational Science, University of Pennsylvania, Philadelphia, PA, United States of America.
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3
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Gorjifard S, Jores T, Tonnies J, Mueth NA, Bubb K, Wrightsman T, Buckler ES, Fields S, Cuperus JT, Queitsch C. Arabidopsis and Maize Terminator Strength is Determined by GC Content, Polyadenylation Motifs and Cleavage Probability. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.06.16.545379. [PMID: 37398426 PMCID: PMC10312805 DOI: 10.1101/2023.06.16.545379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
The 3' end of a gene, often called a terminator, modulates mRNA stability, localization, translation, and polyadenylation. Here, we adapted Plant STARR-seq, a massively parallel reporter assay, to measure the activity of over 50,000 terminators from the plants Arabidopsis thaliana and Zea mays. We characterize thousands of plant terminators, including many that outperform bacterial terminators commonly used in plants. Terminator activity is species-specific, differing in tobacco leaf and maize protoplast assays. While recapitulating known biology, our results reveal the relative contributions of polyadenylation motifs to terminator strength. We built a computational model to predict terminator strength and used it to conduct in silico evolution that generated optimized synthetic terminators. Additionally, we discover alternative polyadenylation sites across tens of thousands of terminators; however, the strongest terminators tend to have a dominant cleavage site. Our results establish features of plant terminator function and identify strong naturally occurring and synthetic terminators.
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Affiliation(s)
- Sayeh Gorjifard
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Tobias Jores
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Jackson Tonnies
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
- Graduate Program in Biology, University of Washington, Seattle, WA 98195
| | - Nicholas A Mueth
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Kerry Bubb
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Travis Wrightsman
- Section of Plant Breeding and Genetics, Cornell University, Ithaca, NY 14853
| | - Edward S Buckler
- Section of Plant Breeding and Genetics, Cornell University, Ithaca, NY 14853
- Agricultural Research Service, United States Department of Agriculture, Ithaca, NY 14853
- Institute for Genomic Diversity, Cornell University, Ithaca, NY 14853
| | - Stanley Fields
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
- Department of Medicine, University of Washington, Seattle, WA 98195
| | - Josh T Cuperus
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Christine Queitsch
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
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4
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Iida E, Kuriyama K, Tabara M, Takeda A, Suzuki N, Moriyama H, Fukuhara T. Structural features of T-DNA that induce transcriptional gene silencing during agroinfiltration. PLANT BIOTECHNOLOGY (TOKYO, JAPAN) 2023; 40:289-299. [PMID: 38434119 PMCID: PMC10905568 DOI: 10.5511/plantbiotechnology.23.0719a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 07/19/2023] [Indexed: 03/05/2024]
Abstract
Agrobacterium tumefaciens (Rhizobium radiobacter) is used for the transient expression of foreign genes by the agroinfiltration method, but the introduction of foreign genes often induces transcriptional and/or post-transcriptional gene silencing (TGS and/or PTGS). In this study, we characterized the structural features of T-DNA that induce TGS during agroinfiltration. When A. tumefaciens cells harboring an empty T-DNA plasmid containing the cauliflower mosaic virus (CaMV) 35S promoter were infiltrated into the leaves of Nicotiana benthamiana line 16c with a GFP gene over-expressed under the control of the same promoter, no small interfering RNAs (siRNAs) were derived from the GFP sequence. However, siRNAs derived from the CaMV 35S promoter were detected, indicating that TGS against the GFP gene was induced. When the GFP gene was inserted into the T-DNA plasmid, PTGS against the GFP gene was induced whereas TGS against the CaMV 35S promoter was suppressed. We also showed the importance of terminator sequences in T-DNA for gene silencing. Therefore, depending on the combination of promoter, terminator and coding sequences on T-DNA and the host nuclear genome, either or both TGS and/or PTGS could be induced by agroinfiltration. Furthermore, we showed the possible involvement of three siRNA-producing Dicers (DCL2, DCL3 and DCL4) in the induction of TGS by the co-agroinfiltration method. Especially, DCL2 was probably the most important among them in the initial step of TGS induction. These results are valuable for controlling gene expression by agroinfiltration.
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Affiliation(s)
- Emi Iida
- Department of Applied Biological Sciences, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Kazunori Kuriyama
- Department of Applied Biological Sciences, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Midori Tabara
- Department of Applied Biological Sciences, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
- Ritsumeikan-Global Innovation Research Organization, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Atsushi Takeda
- College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Nobuhiro Suzuki
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama 710-0046, Japan
| | - Hiromitsu Moriyama
- Department of Applied Biological Sciences, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Toshiyuki Fukuhara
- Department of Applied Biological Sciences, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
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5
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Brooks EG, Elorriaga E, Liu Y, Duduit JR, Yuan G, Tsai CJ, Tuskan GA, Ranney TG, Yang X, Liu W. Plant Promoters and Terminators for High-Precision Bioengineering. BIODESIGN RESEARCH 2023; 5:0013. [PMID: 37849460 PMCID: PMC10328392 DOI: 10.34133/bdr.0013] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 06/12/2023] [Indexed: 10/19/2023] Open
Abstract
High-precision bioengineering and synthetic biology require fine-tuning gene expression at both transcriptional and posttranscriptional levels. Gene transcription is tightly regulated by promoters and terminators. Promoters determine the timing, tissues and cells, and levels of the expression of genes. Terminators mediate transcription termination of genes and affect mRNA levels posttranscriptionally, e.g., the 3'-end processing, stability, translation efficiency, and nuclear to cytoplasmic export of mRNAs. The promoter and terminator combination affects gene expression. In the present article, we review the function and features of plant core promoters, proximal and distal promoters, and terminators, and their effects on and benchmarking strategies for regulating gene expression.
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Affiliation(s)
- Emily G. Brooks
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27607, USA
| | - Estefania Elorriaga
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27607, USA
| | - Yang Liu
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - James R. Duduit
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27607, USA
| | - Guoliang Yuan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Chung-Jui Tsai
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Warnell School of Forestry and Natural Resource, University of Georgia, Athens, GA 30602, USA
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Gerald A. Tuskan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Thomas G. Ranney
- Mountain Crop Improvement Lab, Department of Horticultural Science, Mountain Horticultural Crops Research and Extension Center, North Carolina State University, Mills River, NC 28759, USA
| | - Xiaohan Yang
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Warnell School of Forestry and Natural Resource, University of Georgia, Athens, GA 30602, USA
| | - Wusheng Liu
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27607, USA
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6
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de Felippes FF, Waterhouse PM. Plant terminators: the unsung heroes of gene expression. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:2239-2250. [PMID: 36477559 PMCID: PMC10082929 DOI: 10.1093/jxb/erac467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 11/25/2022] [Indexed: 06/06/2023]
Abstract
To be properly expressed, genes need to be accompanied by a terminator, a region downstream of the coding sequence that contains the information necessary for the maturation of the mRNA 3' end. The main event in this process is the addition of a poly(A) tail at the 3' end of the new transcript, a critical step in mRNA biology that has important consequences for the expression of genes. Here, we review the mechanism leading to cleavage and polyadenylation of newly transcribed mRNAs and how this process can affect the final levels of gene expression. We give special attention to an aspect often overlooked, the effect that different terminators can have on the expression of genes. We also discuss some exciting findings connecting the choice of terminator to the biogenesis of small RNAs, which are a central part of one of the most important mechanisms of regulation of gene expression in plants.
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Affiliation(s)
| | - Peter M Waterhouse
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology (QUT), Brisbane, QLD, Australia
- ARC Centre of Excellence for Plant Success in Nature & Agriculture, QUT, Brisbane, QLD, Australia
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7
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de Felippes FF, Shand K, Waterhouse PM. Identification of a Transferrable Terminator Element That Inhibits Small RNA Production and Improves Transgene Expression Levels. FRONTIERS IN PLANT SCIENCE 2022; 13:877793. [PMID: 35651775 PMCID: PMC9149433 DOI: 10.3389/fpls.2022.877793] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 04/27/2022] [Indexed: 06/06/2023]
Abstract
The role of terminators is more commonly associated with the polyadenylation and 3' end formation of new transcripts. Recent evidence, however, suggests that this regulatory region can have a dramatic impact on gene expression. Nonetheless, little is known about the molecular mechanisms leading to the improvements associated with terminator usage in plants and the different elements in a plant terminator. Here, we identified an element in the Arabidopsis HSP18.2 terminator (tHSP) to be essential for the high level of expression seen for transgenes under the regulation of this terminator. Our molecular analyses suggest that this newly identified sequence acts to improve transcription termination, leading to fewer read-through events and decreased amounts of small RNAs originating from the transgene. Besides protecting against silencing, the tHSP-derived sequence positively impacts splicing efficiency, helping to promote gene expression. Moreover, we show that this sequence can be used to generate chimeric terminators with enhanced efficiency, resulting in stronger transgene expression and significantly expanding the availability of efficient terminators that can be part of good expression systems. Thus, our data make an important contribution toward a better understanding of plant terminators, with the identification of a new element that has a direct impact on gene expression, and at the same time, creates new possibilities to modulate gene expression via the manipulation of 3' regulatory regions.
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Affiliation(s)
- Felipe Fenselau de Felippes
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Research Council (ARC) Centre of Excellence for Plant Success in Nature and Agriculture, Queensland University of Technology, Brisbane, QLD, Australia
| | - Kylie Shand
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD, Australia
| | - Peter M. Waterhouse
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Research Council (ARC) Centre of Excellence for Plant Success in Nature and Agriculture, Queensland University of Technology, Brisbane, QLD, Australia
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8
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Smirnov A, Battulin N. Concatenation of Transgenic DNA: Random or Orchestrated? Genes (Basel) 2021; 12:genes12121969. [PMID: 34946918 PMCID: PMC8701086 DOI: 10.3390/genes12121969] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/08/2021] [Accepted: 12/09/2021] [Indexed: 12/18/2022] Open
Abstract
Generation of transgenic organisms by pronuclear microinjection has become a routine procedure. However, while the process of DNA integration in the genome is well understood, we still do not know much about the recombination between transgene molecules that happens in the first moments after DNA injection. Most of the time, injected molecules are joined together in head-to-tail tandem repeats-the so-called concatemers. In this review, we focused on the possible concatenation mechanisms and how they could be studied with genetic reporters tracking individual copies in concatemers. We also discuss various features of concatemers, including palindromic junctions and repeat-induced gene silencing (RIGS). Finally, we speculate how cooperation of DNA repair pathways creates a multicopy concatenated insert.
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Affiliation(s)
- Alexander Smirnov
- Laboratory of Developmental Genetics, Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia;
| | - Nariman Battulin
- Laboratory of Developmental Genetics, Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia;
- Institute of Genetic Technologies, Novosibirsk State University, 630090 Novosibirsk, Russia
- Correspondence:
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9
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Hung YH, Slotkin RK. The initiation of RNA interference (RNAi) in plants. CURRENT OPINION IN PLANT BIOLOGY 2021; 61:102014. [PMID: 33657510 DOI: 10.1016/j.pbi.2021.102014] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/19/2021] [Accepted: 01/24/2021] [Indexed: 05/15/2023]
Abstract
When an mRNA enters into the RNA degradation pathway called RNA interference (RNAi), it is cleaved into small interfering RNAs (siRNAs) that then target complementary mRNAs for destruction. The consequence of entry into RNAi is mRNA degradation, post-transcriptional silencing and in some cases transcriptional silencing. RNAi functions as a defense against transposable element and virus activity, and in plants, RNAi additionally plays a role in development by regulating some genes. However, it is unknown how specific transcripts are selected for RNAi, and how most genic mRNAs steer clear. This Current Opinion article explores the key question of how RNAs are selected for entry into RNAi, and proposes models that enable the cell to distinguish between transcripts to translate versus destroy.
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Affiliation(s)
- Yu-Hung Hung
- Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA
| | - R Keith Slotkin
- Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA; Division of Biological Sciences, University of Missouri-Columbia, 65211, USA.
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10
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F de Felippes F, McHale M, Doran RL, Roden S, Eamens AL, Finnegan EJ, Waterhouse PM. The key role of terminators on the expression and post-transcriptional gene silencing of transgenes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:96-112. [PMID: 32603508 DOI: 10.1111/tpj.14907] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/08/2020] [Accepted: 06/17/2020] [Indexed: 05/18/2023]
Abstract
Transgenes have become essential to modern biology, being an important tool in functional genomic studies and also in the development of biotechnological products. One of the major challenges in the generation of transgenic lines concerns the expression of transgenes, which, compared to endogenes, are particularly susceptible to silencing mediated by small RNAs (sRNAs). Several reasons have been put forward to explain why transgenes often trigger the production of sRNAs, such as the high level of expression induced by commonly used strong constitutive promoters, the lack of introns, and features resembling viral and other exogenous sequences. However, the relative contributions of the different genomic elements with respect to protecting genes from the silencing machinery and their molecular mechanisms remain unclear. Here, we present the results of a mutagenesis screen conceived to identify features involved in the protection of endogenes against becoming a template for the production of sRNAs. Interestingly, all of the recovered mutants had alterations in genes with proposed function in transcription termination, suggesting a central role of terminators in this process. Indeed, using a GFP reporter system, we show that, among different genetic elements tested, the terminator sequence had the greatest effect on transgene-derived sRNA accumulation and that a well-defined poly(A) site might be especially important. Finally, we describe an unexpected mechanism, where transgenes containing certain intron/terminator combinations lead to an increase in the production of sRNAs, which appears to interfere with splicing.
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Affiliation(s)
- Felipe F de Felippes
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia
| | - Marcus McHale
- Plant Systems Biology Laboratory, Áras de Brún, National University of Ireland Galway (NUIG), Research Road, Galway, H91TK33, Ireland
| | - Rachel L Doran
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia
| | - Sally Roden
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia
| | - Andrew L Eamens
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW, 2308, Australia
| | - E Jean Finnegan
- CSIRO Agriculture and Food, GPO Box 1700, Canberra, ACT, 2601, Australia
| | - Peter M Waterhouse
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia
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11
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Bernardes WS, Menossi M. Plant 3' Regulatory Regions From mRNA-Encoding Genes and Their Uses to Modulate Expression. FRONTIERS IN PLANT SCIENCE 2020; 11:1252. [PMID: 32922424 PMCID: PMC7457121 DOI: 10.3389/fpls.2020.01252] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 07/29/2020] [Indexed: 05/08/2023]
Abstract
Molecular biotechnology has made it possible to explore the potential of plants for different purposes. The 3' regulatory regions have a great diversity of cis-regulatory elements directly involved in polyadenylation, stability, transport and mRNA translation, essential to achieve the desired levels of gene expression. A complex interaction between the cleavage and polyadenylation molecular complex and cis-elements determine the polyadenylation site, which may result in the choice of non-canonical sites, resulting in alternative polyadenylation events, involved in the regulation of more than 80% of the genes expressed in plants. In addition, after transcription, a wide array of RNA-binding proteins interacts with cis-acting elements located mainly in the 3' untranslated region, determining the fate of mRNAs in eukaryotic cells. Although a small number of 3' regulatory regions have been identified and validated so far, many studies have shown that plant 3' regulatory regions have a higher potential to regulate gene expression in plants compared to widely used 3' regulatory regions, such as NOS and OCS from Agrobacterium tumefaciens and 35S from cauliflower mosaic virus. In this review, we discuss the role of 3' regulatory regions in gene expression, and the superior potential that plant 3' regulatory regions have compared to NOS, OCS and 35S 3' regulatory regions.
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12
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de Felippes FF, Waterhouse PM. The Whys and Wherefores of Transitivity in Plants. FRONTIERS IN PLANT SCIENCE 2020; 11:579376. [PMID: 32983223 PMCID: PMC7488869 DOI: 10.3389/fpls.2020.579376] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 08/14/2020] [Indexed: 05/05/2023]
Abstract
Transitivity in plants is a mechanism that produces secondary small interfering RNAs (siRNAs) from a transcript targeted by primary small RNAs (sRNAs). It expands the silencing signal to additional sequences of the transcript. The process requires RNA-dependent RNA polymerases (RDRs), which convert single-stranded RNA targets into a double-stranded (ds) RNA, the precursor of siRNAs and is critical for effective and amplified responses to virus infection. It is also important for the production of endogenous secondary siRNAs, such as phased siRNAs (phasiRNAs), which regulate several genes involved in development and adaptation. Transitivity on endogenous transcripts is very specific, utilizing special primary sRNAs, such as miRNAs with unique features, and particular ARGONAUTEs. In contrast, transitivity on transgene and virus (exogenous) transcripts is more generic. This dichotomy of responses implies the existence of a mechanism that differentiates self from non-self targets. In this work, we examine the possible mechanistic process behind the dichotomy and the intriguing counter-intuitive directionality of transitive sequence-spread in plants.
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