1
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Zhu P, Schon M, Questa J, Nodine M, Dean C. Causal role of a promoter polymorphism in natural variation of the Arabidopsis floral repressor gene FLC. Curr Biol 2023; 33:4381-4391.e3. [PMID: 37729909 DOI: 10.1016/j.cub.2023.08.079] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 07/06/2023] [Accepted: 08/25/2023] [Indexed: 09/22/2023]
Abstract
Noncoding polymorphism frequently associates with phenotypic variation, but causation and mechanism are rarely established. Noncoding single-nucleotide polymorphisms (SNPs) characterize the major haplotypes of the Arabidopsis thaliana floral repressor gene FLOWERING LOCUS C (FLC). This noncoding polymorphism generates a range of FLC expression levels, determining the requirement for and the response to winter cold. The major adaptive determinant of these FLC haplotypes was shown to be the autumnal levels of FLC expression. Here, we investigate how noncoding SNPs influence FLC transcriptional output. We identify an upstream transcription start site (uTSS) cluster at FLC, whose usage is increased by an A variant at the promoter SNP-230. This variant is present in relatively few Arabidopsis accessions, with the majority containing G at this site. We demonstrate a causal role for the A variant at -230 in reduced FLC transcriptional output. The G variant upregulates FLC expression redundantly with the major transcriptional activator FRIGIDA (FRI). We demonstrate an additive interaction of SNP-230 with an intronic SNP+259, which also differentially influences uTSS usage. Combinatorial interactions between noncoding SNPs and transcriptional activators thus generate quantitative variation in FLC transcription that has facilitated the adaptation of Arabidopsis accessions to distinct climates.
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Affiliation(s)
- Pan Zhu
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Michael Schon
- Laboratory of Molecular Biology, Wageningen University, Wageningen 6708 PB, the Netherlands; Gregor Mendel Institute, Vienna Biocenter, Vienna 1030, Austria
| | - Julia Questa
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Michael Nodine
- Laboratory of Molecular Biology, Wageningen University, Wageningen 6708 PB, the Netherlands; Gregor Mendel Institute, Vienna Biocenter, Vienna 1030, Austria
| | - Caroline Dean
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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2
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Yang EJ, Nemhauser JL. Building a pipeline to identify and engineer constitutive and repressible promoters. QUANTITATIVE PLANT BIOLOGY 2023; 4:e12. [PMID: 37901686 PMCID: PMC10600573 DOI: 10.1017/qpb.2023.10] [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: 10/13/2022] [Revised: 07/24/2023] [Accepted: 09/13/2023] [Indexed: 10/31/2023]
Abstract
To support the increasingly complex circuits needed for plant synthetic biology applications, additional constitutive promoters are essential. Reusing promoter parts can lead to difficulty in cloning, increased heterogeneity between transformants, transgene silencing and trait instability. We have developed a pipeline to identify genes that have stable expression across a wide range of Arabidopsis tissues at different developmental stages and have identified a number of promoters that are well expressed in both transient (Nicotiana benthamiana) and stable (Arabidopsis) transformation assays. We have also introduced two genome-orthogonal gRNA target sites in a subset of the screened promoters, converting them into NOR logic gates. The work here establishes a pipeline to screen for additional constitutive promoters and can form the basis of constructing more complex information processing circuits in the future.
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Affiliation(s)
- Eric J.Y. Yang
- Department of Biology, University of Washington, Seattle, WA, USA
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3
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Milito A, Aschern M, McQuillan JL, Yang JS. Challenges and advances towards the rational design of microalgal synthetic promoters in Chlamydomonas reinhardtii. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:3833-3850. [PMID: 37025006 DOI: 10.1093/jxb/erad100] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 03/24/2023] [Indexed: 06/19/2023]
Abstract
Microalgae hold enormous potential to provide a safe and sustainable source of high-value compounds, acting as carbon-fixing biofactories that could help to mitigate rapidly progressing climate change. Bioengineering microalgal strains will be key to optimizing and modifying their metabolic outputs, and to render them competitive with established industrial biotechnology hosts, such as bacteria or yeast. To achieve this, precise and tuneable control over transgene expression will be essential, which would require the development and rational design of synthetic promoters as a key strategy. Among green microalgae, Chlamydomonas reinhardtii represents the reference species for bioengineering and synthetic biology; however, the repertoire of functional synthetic promoters for this species, and for microalgae generally, is limited in comparison to other commercial chassis, emphasizing the need to expand the current microalgal gene expression toolbox. Here, we discuss state-of-the-art promoter analyses, and highlight areas of research required to advance synthetic promoter development in C. reinhardtii. In particular, we exemplify high-throughput studies performed in other model systems that could be applicable to microalgae, and propose novel approaches to interrogating algal promoters. We lastly outline the major limitations hindering microalgal promoter development, while providing novel suggestions and perspectives for how to overcome them.
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Affiliation(s)
- Alfonsina Milito
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, Bellaterra, Barcelona, Spain
| | - Moritz Aschern
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, Bellaterra, Barcelona, Spain
| | - Josie L McQuillan
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK
| | - Jae-Seong Yang
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, Bellaterra, Barcelona, Spain
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4
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Palos K, Yu L, Railey CE, Nelson Dittrich AC, Nelson ADL. Linking discoveries, mechanisms, and technologies to develop a clearer perspective on plant long noncoding RNAs. THE PLANT CELL 2023; 35:1762-1786. [PMID: 36738093 PMCID: PMC10226578 DOI: 10.1093/plcell/koad027] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 12/19/2022] [Accepted: 12/22/2022] [Indexed: 05/30/2023]
Abstract
Long noncoding RNAs (lncRNAs) are a large and diverse class of genes in eukaryotic genomes that contribute to a variety of regulatory processes. Functionally characterized lncRNAs play critical roles in plants, ranging from regulating flowering to controlling lateral root formation. However, findings from the past decade have revealed that thousands of lncRNAs are present in plant transcriptomes, and characterization has lagged far behind identification. In this setting, distinguishing function from noise is challenging. However, the plant community has been at the forefront of discovery in lncRNA biology, providing many functional and mechanistic insights that have increased our understanding of this gene class. In this review, we examine the key discoveries and insights made in plant lncRNA biology over the past two and a half decades. We describe how discoveries made in the pregenomics era have informed efforts to identify and functionally characterize lncRNAs in the subsequent decades. We provide an overview of the functional archetypes into which characterized plant lncRNAs fit and speculate on new avenues of research that may uncover yet more archetypes. Finally, this review discusses the challenges facing the field and some exciting new molecular and computational approaches that may help inform lncRNA comparative and functional analyses.
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Affiliation(s)
- Kyle Palos
- Boyce Thompson Institute, Cornell University, Ithaca, NY 14853, USA
| | - Li’ang Yu
- Boyce Thompson Institute, Cornell University, Ithaca, NY 14853, USA
| | - Caylyn E Railey
- Boyce Thompson Institute, Cornell University, Ithaca, NY 14853, USA
- Plant Biology Graduate Field, Cornell University, Ithaca, NY 14853, USA
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5
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Diego-Martin B, Pérez-Alemany J, Candela-Ferre J, Corbalán-Acedo A, Pereyra J, Alabadí D, Jami-Alahmadi Y, Wohlschlegel J, Gallego-Bartolomé J. The TRIPLE PHD FINGERS proteins are required for SWI/SNF complex-mediated +1 nucleosome positioning and transcription start site determination in Arabidopsis. Nucleic Acids Res 2022; 50:10399-10417. [PMID: 36189880 PMCID: PMC9561266 DOI: 10.1093/nar/gkac826] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 09/08/2022] [Accepted: 09/16/2022] [Indexed: 11/14/2022] Open
Abstract
Eukaryotes have evolved multiple ATP-dependent chromatin remodelers to shape the nucleosome landscape. We recently uncovered an evolutionarily conserved SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeler complex in plants reminiscent of the mammalian BAF subclass, which specifically incorporates the MINUSCULE (MINU) catalytic subunits and the TRIPLE PHD FINGERS (TPF) signature subunits. Here we report experimental evidence that establishes the functional relevance of TPF proteins for the complex activity. Our results show that depletion of TPF triggers similar pleiotropic phenotypes and molecular defects to those found in minu mutants. Moreover, we report the genomic location of MINU2 and TPF proteins as representative members of this SWI/SNF complex and their impact on nucleosome positioning and transcription. These analyses unravel the binding of the complex to thousands of genes where it modulates the position of the +1 nucleosome. These targets tend to produce 5′-shifted transcripts in the tpf and minu mutants pointing to the participation of the complex in alternative transcription start site usage. Interestingly, there is a remarkable correlation between +1 nucleosome shift and 5′ transcript length change suggesting their functional connection. In summary, this study unravels the function of a plant SWI/SNF complex involved in +1 nucleosome positioning and transcription start site determination.
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Affiliation(s)
- Borja Diego-Martin
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
| | - Jaime Pérez-Alemany
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
| | - Joan Candela-Ferre
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
| | - Antonio Corbalán-Acedo
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
| | - Juan Pereyra
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
| | - David Alabadí
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
| | - Yasaman Jami-Alahmadi
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - James Wohlschlegel
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Javier Gallego-Bartolomé
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
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6
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Genome-wide analysis of the CAD gene family reveals two bona fide CAD genes in oil palm. 3 Biotech 2022; 12:149. [PMID: 35747504 PMCID: PMC9209623 DOI: 10.1007/s13205-022-03208-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 05/21/2022] [Indexed: 11/01/2022] Open
Abstract
Cinnamyl alcohol dehydrogenase (CAD) is the key enzyme for lignin biosynthesis in plants. In this study, genome-wide analysis was performed to identify CAD genes in oil palm (Elaeis guineensis). Phylogenetic analysis was then conducted to select the bona fide EgCADs. The bona fide EgCAD genes and their respective 5' flanking regions were cloned and analysed. Their expression profiles were evaluated in various organs using RT-PCR. Seven EgCAD genes (EgCAD1-7) were identified and divided into four phylogenetic groups. EgCAD1 and EgCAD2 display high sequence similarities with other bona fide CADs and possess all the signature motifs of the bona fide CAD. They also display similar 3D protein structures. Gene expression analysis showed that EgCAD1 was expressed most abundantly in the root tissues, while EgCAD2 was expressed constitutively in all the tissues studied. EgCAD1 possesses only one transcription start site, while EgCAD2 has five. Interestingly, a TC microsatellite was found in the 5' flanking region of EgCAD2. The 5' flanking regions of EgCAD1 and EgCAD2 contain lignin-associated regulatory elements i.e. AC-elements, and other defence-related motifs, including W-box, GT-1 motif and CGTCA-motif. Altogether, these results imply that EgCAD1 and EgCAD2 are bona fide CAD involved in lignin biosynthesis during the normal development of oil palm and in response to stresses. Our findings shed some light on the roles of the bona fide CAD genes in oil palm and pave the way for manipulating lignin content in oil palm through a genetic approach. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-022-03208-0.
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7
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Sequence-based evaluation of promoter context for prediction of transcription start sites in Arabidopsis and rice. Sci Rep 2022; 12:6976. [PMID: 35484393 PMCID: PMC9050755 DOI: 10.1038/s41598-022-11169-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 04/20/2022] [Indexed: 11/20/2022] Open
Abstract
Genes are transcribed from transcription start sites (TSSs), and their position in a genome is strictly controlled to avoid mis-expression of undesired regions. In this study, we designed and developed a methodology for the evaluation of promoter context, which detects proximal promoter regions from − 200 to − 60 bp relative to a TSS, in Arabidopsis and rice genomes. The method positively evaluates spacer sequences and Regulatory Element Groups, but not core promoter elements like TATA boxes, and is able to predict the position of a TSS within a width of 200 bp. An important feature of the evaluation/prediction method is its independence of the core promoter elements, which was demonstrated by successful prediction of all the TATA, GA, and coreless types of promoters without notable differences in the accuracy of prediction. The positive relationship identified between the evaluation scores and gene expression levels suggests that this method is useful for the evaluation of promoter maturity.
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8
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Kudo H, Matsuo M, Satoh S, Hata T, Hachisu R, Nakamura M, Yamamoto YY, Kimura H, Matsui M, Obokata J. Cryptic promoter activation occurs by at least two different mechanisms in the Arabidopsis genome. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 108:29-39. [PMID: 34252235 DOI: 10.1111/tpj.15420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 07/08/2021] [Indexed: 06/13/2023]
Abstract
In gene-trap screening of plant genomes, promoterless reporter constructs are often expressed without trapping of annotated gene promoters. The molecular basis of this phenomenon, which has been interpreted as the trapping of cryptic promoters, is poorly understood. Here, we found that cryptic promoter activation occurs by at least two different mechanisms using Arabidopsis gene-trap lines in which a firefly luciferase (LUC) open reading frame (ORF) without an apparent promoter sequence was expressed from intergenic regions: one mechanism is 'cryptic promoter capturing', in which the LUC ORF captured pre-existing promoter-like chromatin marked by H3K4me3 and H2A.Z, and the other is 'promoter de novo origination', in which the promoter chromatin was newly formed near the 5' end of the inserted LUC ORF. The latter finding raises a question as to how the inserted LUC ORF sequence is involved in this phenomenon. To examine this, we performed a model experiment with chimeric LUC genes in transgenic plants. Using Arabidopsis psaH1 promoter-LUC constructs, we found that the functional core promoter region, where transcription start sites (TSSs) occur, cannot simply be determined by the upstream nor core promoter sequences; rather, its positioning proximal to the inserted LUC ORF sequence was more critical. This result suggests that the insertion of the coding sequence alters the local distribution of TSSs in the plant genome. The possible impact of the two types of cryptic promoter activation mechanisms on plant genome evolution and endosymbiotic gene transfer is discussed.
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Affiliation(s)
- Hisayuki Kudo
- Center for G Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan
| | - Mitsuhiro Matsuo
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, 1-5 Hangi-cho, Sakyo-ku, Kyoto, 606-8522, Japan
| | - Soichirou Satoh
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, 1-5 Hangi-cho, Sakyo-ku, Kyoto, 606-8522, Japan
| | - Takayuki Hata
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, 1-5 Hangi-cho, Sakyo-ku, Kyoto, 606-8522, Japan
| | - Rei Hachisu
- Center for G Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan
| | - Masayuki Nakamura
- Center for G Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan
| | - Yoshiharu Y Yamamoto
- Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagito, Gihu-shi, Gifu, 501-1193, Japan
| | - Hiroshi Kimura
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama City, Kanagawa, 226-8501, Japan
| | - Minami Matsui
- RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Junichi Obokata
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, 1-5 Hangi-cho, Sakyo-ku, Kyoto, 606-8522, Japan
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9
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Um T, Park T, Shim JS, Kim YS, Lee GS, Choi IY, Kim JK, Seo JS, Park SC. Application of Upstream Open Reading Frames (uORFs) Editing for the Development of Stress-Tolerant Crops. Int J Mol Sci 2021; 22:ijms22073743. [PMID: 33916772 PMCID: PMC8038395 DOI: 10.3390/ijms22073743] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/27/2021] [Accepted: 03/31/2021] [Indexed: 12/20/2022] Open
Abstract
Global population growth and climate change are posing increasing challenges to the production of a stable crop supply using current agricultural practices. The generation of genetically modified (GM) crops has contributed to improving crop stress tolerance and productivity; however, many regulations are still in place that limit their commercialization. Recently, alternative biotechnology-based strategies, such as gene-edited (GE) crops, have been in the spotlight. Gene-editing technology, based on the clustered regularly interspaced short palindromic repeats (CRISPR) platform, has emerged as a revolutionary tool for targeted gene mutation, and has received attention as a game changer in the global biotechnology market. Here, we briefly introduce the concept of upstream open reading frames (uORFs) editing, which allows for control of the translation of downstream ORFs, and outline the potential for enhancing target gene expression by mutating uORFs. We discuss the current status of developing stress-tolerant crops, and discuss uORF targets associated with salt stress-responsive genes in rice that have already been verified by transgenic research. Finally, we overview the strategy for developing GE crops using uORF editing via the CRISPR-Cas9 system. A case is therefore made that the mutation of uORFs represents an efficient method for developing GE crops and an expansion of the scope of application of genome editing technology.
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Affiliation(s)
- Taeyoung Um
- Agriculture and Life Sciences Research Institute, Kangwon National University, Chuncheon 24341, Korea; (T.U.); (Y.S.K.)
| | - Taehyeon Park
- Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang 25354, Korea; (T.P.); (J.-K.K.)
| | - Jae Sung Shim
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Korea;
| | - Youn Shic Kim
- Agriculture and Life Sciences Research Institute, Kangwon National University, Chuncheon 24341, Korea; (T.U.); (Y.S.K.)
| | - Gang-Seob Lee
- Department of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju 54874, Korea;
| | - Ik-Young Choi
- Department of Agricultural and Life Industry, Kangwon National University, Chuncheon 24341, Korea;
| | - Ju-Kon Kim
- Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang 25354, Korea; (T.P.); (J.-K.K.)
| | - Jun Sung Seo
- Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang 25354, Korea; (T.P.); (J.-K.K.)
- Correspondence: (J.S.S.); (S.C.P.); Tel.: +82-33-339-5826 (J.S.S.); +82-63-238-4584 (S.C.P.)
| | - Soo Chul Park
- Department of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju 54874, Korea;
- Correspondence: (J.S.S.); (S.C.P.); Tel.: +82-33-339-5826 (J.S.S.); +82-63-238-4584 (S.C.P.)
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10
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Tokizawa M, Enomoto T, Ito H, Wu L, Kobayashi Y, Mora-Macías J, Armenta-Medina D, Iuchi S, Kobayashi M, Nomoto M, Tada Y, Fujita M, Shinozaki K, Yamamoto YY, Kochian LV, Koyama H. High affinity promoter binding of STOP1 is essential for early expression of novel aluminum-induced resistance genes GDH1 and GDH2 in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:2769-2789. [PMID: 33481007 DOI: 10.1093/jxb/erab031] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 05/28/2023]
Abstract
Malate efflux from roots, which is regulated by the transcription factor STOP1 (SENSITIVE-TO-PROTON-RHIZOTOXICITY1) and mediates aluminum-induced expression of ALUMINUM-ACTIVATED-MALATE-TRANSPORTER1 (AtALMT1), is critical for aluminum resistance in Arabidopsis thaliana. Several studies showed that AtALMT1 expression in roots is rapidly observed in response to aluminum; this early induction is an important mechanism to immediately protect roots from aluminum toxicity. Identifying the molecular mechanisms that underlie rapid aluminum resistance responses should lead to a better understanding of plant aluminum sensing and signal transduction mechanisms. In this study, we observed that GFP-tagged STOP1 proteins accumulated in the nucleus soon after aluminum treatment. The rapid aluminum-induced STOP1-nuclear localization and AtALMT1 induction were detected in the presence of a protein synthesis inhibitor, suggesting that post-translational regulation is involved in these events. STOP1 also regulated rapid aluminum-induced expression for other genes that carry a functional/high-affinity STOP1-binding site in their promoter, including STOP2, GLUTAMATE-DEHYDROGENASE1 and 2 (GDH1 and 2). However STOP1 did not regulate Al resistance genes which have no functional STOP1-binding site such as ALUMINUM-SENSITIVE3, suggesting that the binding of STOP1 in the promoter is essential for early induction. Finally, we report that GDH1 and 2 which are targets of STOP1, are novel aluminum-resistance genes in Arabidopsis.
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Affiliation(s)
- Mutsutomo Tokizawa
- Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan
- Global Institute for Food Security, University of Saskatchewan, Saskatoon S7N 4J8, Canada
| | - Takuo Enomoto
- Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan
| | - Hiroki Ito
- Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan
| | - Liujie Wu
- Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan
- University of Warwick, UK
| | - Yuriko Kobayashi
- Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan
| | - Javier Mora-Macías
- Global Institute for Food Security, University of Saskatchewan, Saskatoon S7N 4J8, Canada
| | - Dagoberto Armenta-Medina
- CONACyT Consejo Nacional de Ciencia y Tecnología, Dirección de Cátedras, Insurgentes Sur 1582, Crédito Constructor, 03940 Ciudad de México, México
- INFOTEC Centro de Investigación e Innovación en Tecnologías de la Informacion y Comunicación, Circuito Tecnopolo Sur No 112, Fracc. Tecnopolo Pocitos II, 20313 Aguascalientes, México
| | - Satoshi Iuchi
- RIKEN Bioresource Research Center, Ibaraki 305-0074, Japan
| | | | - Mika Nomoto
- Center for Gene Research, Nagoya University, Nagoya 464-8602, Japan
| | - Yasuomi Tada
- Center for Gene Research, Nagoya University, Nagoya 464-8602, Japan
| | - Miki Fujita
- RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan
| | - Kazuo Shinozaki
- RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan
| | - Yoshiharu Y Yamamoto
- Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan
- RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan
| | - Leon V Kochian
- Global Institute for Food Security, University of Saskatchewan, Saskatoon S7N 4J8, Canada
| | - Hiroyuki Koyama
- Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan
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11
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Zheng X, Chen Y, Zhou Y, Shi K, Hu X, Li D, Ye H, Zhou Y, Wang K. Full-length annotation with multistrategy RNA-seq uncovers transcriptional regulation of lncRNAs in cotton. PLANT PHYSIOLOGY 2021; 185:179-195. [PMID: 33631798 PMCID: PMC8133545 DOI: 10.1093/plphys/kiaa003] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 10/16/2020] [Indexed: 05/11/2023]
Abstract
Long noncoding RNAs (lncRNAs) are crucial factors during plant development and environmental responses. To build an accurate atlas of lncRNAs in the diploid cotton Gossypium arboreum, we combined Isoform-sequencing, strand-specific RNA-seq (ssRNA-seq), and cap analysis gene expression (CAGE-seq) with PolyA-seq and compiled a pipeline named plant full-length lncRNA to integrate multi-strategy RNA-seq data. In total, 9,240 lncRNAs from 21 tissue samples were identified. 4,405 and 4,805 lncRNA transcripts were supported by CAGE-seq and PolyA-seq, respectively, among which 6.7% and 7.2% had multiple transcription start sites (TSSs) and transcription termination sites (TTSs). We revealed that alternative usage of TSS and TTS of lncRNAs occurs pervasively during plant growth. Besides, we uncovered that many lncRNAs act in cis to regulate adjacent protein-coding genes (PCGs). It was especially interesting to observe 64 cases wherein the lncRNAs were involved in the TSS alternative usage of PCGs. We identified lncRNAs that are coexpressed with ovule- and fiber development-associated PCGs, or linked to GWAS single-nucleotide polymorphisms. We mapped the genome-wide binding sites of two lncRNAs with chromatin isolation by RNA purification sequencing. We also validated the transcriptional regulatory role of lnc-Ga13g0352 via virus-induced gene suppression assay, indicating that this lncRNA might act as a dual-functional regulator that either activates or inhibits the transcription of target genes.
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Affiliation(s)
- Xiaomin Zheng
- College of Life Sciences, Wuhan University, Wuhan 430000, China
| | - Yanjun Chen
- College of Life Sciences, Wuhan University, Wuhan 430000, China
| | - Yifan Zhou
- College of Life Sciences, Wuhan University, Wuhan 430000, China
| | - Keke Shi
- College of Life Sciences, Wuhan University, Wuhan 430000, China
| | - Xiao Hu
- College of Life Sciences, Wuhan University, Wuhan 430000, China
| | - Danyang Li
- College of Life Sciences, Wuhan University, Wuhan 430000, China
| | - Hanzhe Ye
- College of Life Sciences, Wuhan University, Wuhan 430000, China
| | - Yu Zhou
- College of Life Sciences, Wuhan University, Wuhan 430000, China
- Institute for Advanced Studies, Wuhan University, Wuhan 430000, China
| | - Kun Wang
- College of Life Sciences, Wuhan University, Wuhan 430000, China
- Author for communication:
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12
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Le NT, Harukawa Y, Miura S, Boer D, Kawabe A, Saze H. Epigenetic regulation of spurious transcription initiation in Arabidopsis. Nat Commun 2020; 11:3224. [PMID: 32591528 PMCID: PMC7319988 DOI: 10.1038/s41467-020-16951-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 06/01/2020] [Indexed: 01/01/2023] Open
Abstract
In plants, epigenetic regulation is critical for silencing transposons and maintaining proper gene expression. However, its impact on the genome-wide transcription initiation landscape remains elusive. By conducting a genome-wide analysis of transcription start sites (TSSs) using cap analysis of gene expression (CAGE) sequencing, we show that thousands of TSSs are exclusively activated in various epigenetic mutants of Arabidopsis thaliana and referred to as cryptic TSSs. Many have not been identified in previous studies, of which up to 65% are contributed by transposons. They possess similar genetic features to regular TSSs and their activation is strongly associated with the ectopic recruitment of RNAPII machinery. The activation of cryptic TSSs significantly alters transcription of nearby TSSs, including those of genes important for development and stress responses. Our study, therefore, sheds light on the role of epigenetic regulation in maintaining proper gene functions in plants by suppressing transcription from cryptic TSSs. Epigenetic regulation can silence transposons and maintain gene expression. Here the authors survey Arabidopsis mutants defective in epigenetic regulation and show ectopic activation of thousands of cryptic TSSs and altered expression of nearby genes demonstrating the importance of suppressing spurious transcription.
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Affiliation(s)
- Ngoc Tu Le
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan
| | - Yoshiko Harukawa
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan
| | - Saori Miura
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan
| | - Damian Boer
- Wageningen University & Research, Droevendaalsesteeg 4, 6708 PB Wageningen, Netherlands
| | - Akira Kawabe
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, 603-8555, Japan
| | - Hidetoshi Saze
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan.
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uORF Shuffling Fine-Tunes Gene Expression at a Deep Level of the Process. PLANTS 2020; 9:plants9050608. [PMID: 32403214 PMCID: PMC7284334 DOI: 10.3390/plants9050608] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/06/2020] [Accepted: 05/08/2020] [Indexed: 01/01/2023]
Abstract
Upstream open reading frames (uORFs) are present in the 5’ leader sequences (or 5’ untranslated regions) upstream of the protein-coding main ORFs (mORFs) in eukaryotic polycistronic mRNA. It is well known that a uORF negatively affects translation of the mORF. Emerging ribosome profiling approaches have revealed that uORFs themselves, as well as downstream mORFs, can be translated. However, it has also been revealed that plants can fine-tune gene expression by modulating uORF-mediated regulation in some situations. This article reviews several proposed mechanisms that enable genes to escape from uORF-mediated negative regulation and gives insight into the application of uORF-mediated regulation for precisely controlling gene expression.
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Multi-strategic RNA-seq analysis reveals a high-resolution transcriptional landscape in cotton. Nat Commun 2019; 10:4714. [PMID: 31624240 PMCID: PMC6797763 DOI: 10.1038/s41467-019-12575-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 09/18/2019] [Indexed: 11/09/2022] Open
Abstract
Cotton is an important natural fiber crop, however, its comprehensive and high-resolution gene map is lacking. Here we integrate four complementary high-throughput techniques, including Pacbio long read Iso-seq, strand-specific RNA-seq, CAGE-seq, and PolyA-seq, to systematically explore the transcription landscape across 16 tissues or different organ types in Gossypium arboreum. We devise a computational pipeline, named IGIA, to reconstruct accurate gene structures from the integrated data. Our results reveal a dynamic and diverse transcriptional map in cotton: tissue-specific gene expression, alternative usage of TSSs and polyadenylation sites, hotspot of alternative splicing, and transcriptional read-through. These regulated events affect many genes in various aspects such as gain or loss of functional RNA motifs and protein domains, fine-tuning of DNA binding activity, and co-regulation for genes in the same complex or pathway. The methods and findings provide valuable resources for further functional genomic studies such as understanding natural SNP variations for plant community.
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Transcription-driven chromatin repression of Intragenic transcription start sites. PLoS Genet 2019; 15:e1007969. [PMID: 30707695 PMCID: PMC6373976 DOI: 10.1371/journal.pgen.1007969] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 02/13/2019] [Accepted: 01/16/2019] [Indexed: 12/31/2022] Open
Abstract
Progression of RNA polymerase II (RNAPII) transcription relies on the appropriately positioned activities of elongation factors. The resulting profile of factors and chromatin signatures along transcription units provides a “positional information system” for transcribing RNAPII. Here, we investigate a chromatin-based mechanism that suppresses intragenic initiation of RNAPII transcription. We demonstrate that RNAPII transcription across gene promoters represses their function in plants. This repression is characterized by reduced promoter-specific molecular signatures and increased molecular signatures associated with RNAPII elongation. The conserved FACT histone chaperone complex is required for this repression mechanism. Genome-wide Transcription Start Site (TSS) mapping reveals thousands of discrete intragenic TSS positions in fact mutants, including downstream promoters that initiate alternative transcript isoforms. We find that histone H3 lysine 4 mono-methylation (H3K4me1), an Arabidopsis RNAPII elongation signature, is enriched at FACT-repressed intragenic TSSs. Our analyses suggest that FACT is required to repress intragenic TSSs at positions that are in part characterized by elevated H3K4me1 levels. In sum, conserved and plant-specific chromatin features correlate with the co-transcriptional repression of intragenic TSSs. Our insights into TSS repression by RNAPII transcription promise to inform the regulation of alternative transcript isoforms and the characterization of gene regulation through the act of pervasive transcription across eukaryotic genomes. Genes represent DNA elements that are transcribed into mRNA. However, the position where transcription actually starts can be dynamically regulated to expand the diversity of RNA isoforms produced from a single gene. Functionally, alternative Transcription Start Sites (TSSs) may generate protein isoforms with differing N-terminal regions and distinct cellular functions. In plants, light signaling regulates protein isoforms largely through regulated TSS selection, emphasizing the biological significance of this mechanism. Despite the importance of alternative TSS selection, little is known about the underlying molecular mechanisms. Here, we characterize for the first time how transcription initiation from an upstream promoter represses alternative downstream promoter activity in plants. This repression mechanism is associated with chromatin changes that are required to maintain precise gene expression control. Specific chromatin signatures are established during transcription via dynamic interactions between the transcription machinery and associated factors. The conserved histone chaperone complex FACT is one such factor involved in regulating the chromatin environment along genes during transcription. We find that mutant plants with reduced FACT activity specifically initiate transcription from thousands of intragenic positions, thus expanding RNA isoform diversity. Overall, our study reveals conserved and plant-specific chromatin features associated with the co-transcriptional repression of downstream intragenic TSSs. These findings promise to help inform the molecular mechanism underlying environmentally-triggered TSS regulation in plants.
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