1
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Mittal M, Dhingra A, Dawar P, Payton P, Rock CD. The role of microRNAs in responses to drought and heat stress in peanut (Arachis hypogaea). THE PLANT GENOME 2023; 16:e20350. [PMID: 37351954 DOI: 10.1002/tpg2.20350] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 04/06/2023] [Accepted: 04/12/2023] [Indexed: 06/24/2023]
Abstract
MicroRNAs (miRNAs) are 21-24 nt small RNAs (sRNAs) that negatively regulate protein-coding genes and/or trigger phased small-interfering RNA (phasiRNA) production. Two thousand nine hundred miRNA families, of which ∼40 are deeply conserved, have been identified in ∼80 different plant species genomes. miRNA functions in response to abiotic stresses is less understood than their roles in development. Only seven peanut MIRNA families are documented in miRBase, yet a reference genome assembly is now published and over 480 plant-like MIRNA loci were predicted in the diploid peanut progenitor Arachis duranensis genome. We explored by computational analysis of a leaf sRNA library and publicly available sRNA, degradome, and transcriptome datasets the miRNA and phasiRNA space associated with drought and heat stresses in peanut. We characterized 33 novel candidate and 33 ancient conserved families of MIRNAs and present degradome evidence for their cleavage activities on mRNA targets, including several noncanonical targets and novel phasiRNA-producing noncoding and mRNA loci with validated novel targets such as miR1509 targeting serine/threonine-protein phosphatase7 and miRc20 and ahy-miR3514 targeting penta-tricopeptide repeats (PPRs), in contradistinction to other claims of miR1509/173/7122 superfamily miRNAs indirectly targeting PPRs via TAS-like noncoding RNA loci. We characterized the inverse correlations of significantly differentially expressed drought- and heat-regulated miRNAs, assayed by sRNA blots or transcriptome datasets, with target mRNA expressions in the same datasets. Meta-analysis of an expression atlas and over representation of miRNA target genes in co-expression networks suggest that miRNAs have functions in unique aspects of peanut gynophore development. Genome-wide MIRNA annotation of the published allopolyploid peanut genome can facilitate molecular breeding of value-added traits.
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Affiliation(s)
- Meenakshi Mittal
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, USA
| | - Anuradha Dhingra
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, USA
| | - Pranav Dawar
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, USA
| | - Paxton Payton
- USDA-ARS Plant Stress and Germplasm Lab, Lubbock, Texas, USA
| | - Christopher D Rock
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, USA
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2
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RNA-seq for revealing the function of the transcriptome. Bioinformatics 2022. [DOI: 10.1016/b978-0-323-89775-4.00002-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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3
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Nachtigall PG, Bovolenta LA. Computational Detection of MicroRNA Targets. Methods Mol Biol 2022; 2257:187-209. [PMID: 34432280 DOI: 10.1007/978-1-0716-1170-8_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
MicroRNAs (miRNAs) are small noncoding RNAs that are recognized as posttranscriptional regulators of gene expression. These molecules have been shown to play important roles in several cellular processes. MiRNAs act on their target by guiding the RISC complex and binding to the mRNA molecule. Thus, it is recognized that the function of a miRNA is determined by the function of its target (s). By using high-throughput methodologies, novel miRNAs are being identified, but their functions remain uncharted. Target validation is crucial to properly understand the specific role of a miRNA in a cellular pathway. However, molecular techniques for experimental validation of miRNA-target interaction are expensive, time-consuming, laborious, and can be not accurate in inferring true interactions. Thus, accurate miRNA target predictions are helpful to understand the functions of miRNAs. There are several algorithms proposed for target prediction and databases containing miRNA-target information. However, these available computational tools for prediction still generate a large number of false positives and fail to detect a considerable number of true targets, which indicates the necessity of highly confident approaches to identify bona fide miRNA-target interactions. This chapter focuses on tools and strategies used for miRNA target prediction, by providing practical insights and outlooks.
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Affiliation(s)
- Pedro Gabriel Nachtigall
- Laboratório Especial de Toxinologia Aplicada, CeTICS, Instituto Butantan, São Paulo, SP, Brazil.
| | - Luiz Augusto Bovolenta
- Department of Morphology, Institute of Biosciences of Botucatu (IBB), São Paulo State University (UNESP), Botucatu, Brazil
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4
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Lacombe S, Bangratz M, Ta HA, Nguyen TD, Gantet P, Brugidou C. Optimized RNA-Silencing Strategies for Rice Ragged Stunt Virus Resistance in Rice. PLANTS 2021; 10:plants10102008. [PMID: 34685817 PMCID: PMC8540896 DOI: 10.3390/plants10102008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/31/2021] [Accepted: 09/21/2021] [Indexed: 11/16/2022]
Abstract
Rice ragged stunt virus (RRSV) is one of the most damaging viruses of the rice culture area in south and far-eastern Asia. To date, no genetic resistance has been identified and only expensive and non-environmentally friendly chemical treatments are deployed to fight this important disease. Non-chemical approaches based on RNA-silencing have been developed as resistance strategies against viruses. Here, we optimized classical miRNA and siRNA-based strategies to obtain efficient and durable resistance to RRSV. miRNA-based strategies are involved in producing artificial miRNA (amiR) targeting viral genomes in plants. Classically, only one amiR is produced from a single construct. We demonstrated for the first time that two amiRs targeting conserved regions of RRSV genomes could be transgenically produced in Nicotiana benthamiana and in rice for a single precursor. Transgenic rice plants producing either one or two amiR were produced. Despite efficient amiR accumulations, miRNA-based strategies with single or double amiRs failed to achieve efficient RRSV resistance in transformed rice plants. This suggests that this strategy may not be adapted to RRSV, which could rapidly evolve to counteract them. Another RNA-silencing-based method for viral resistance concerns producing several viral siRNAs targeting a viral fragment. These viral siRNAs are produced from an inverted repeat construct carrying the targeted viral fragment. Here, we optimized the inverted repeat construct using a chimeric fragment carrying conserved sequences of three different RRSV genes instead of one. Of the three selected homozygous transgenic plants, one failed to accumulate the expected siRNA. The two other ones accumulated siRNAs from either one or three fragments. A strong reduction of RRSV symptoms was observed only in transgenic plants expressing siRNAs. We consequently demonstrated, for the first time, an efficient and environmentally friendly resistance to RRSV in rice based on the siRNA-mediated strategy.
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Affiliation(s)
- Severine Lacombe
- PHIM Plant Health Institute, University Montpellier, IRD, CIRAD, INRAE, Institut Agro, 34090 Montpellier, France; (M.B.); (C.B.)
- Correspondence:
| | - Martine Bangratz
- PHIM Plant Health Institute, University Montpellier, IRD, CIRAD, INRAE, Institut Agro, 34090 Montpellier, France; (M.B.); (C.B.)
| | - Hoang Anh Ta
- Plant Protection Research Institute (PPRI), Bac Tu Liem District, Hanoi 10000, Vietnam;
| | - Thanh Duc Nguyen
- Agricultural Genetics Institute, Bac Tu Liem District, Hanoi 10000, Vietnam;
| | - Pascal Gantet
- UMR DIADE, Université de Montpellier, IRD, 34090 Montpellier, France;
| | - Christophe Brugidou
- PHIM Plant Health Institute, University Montpellier, IRD, CIRAD, INRAE, Institut Agro, 34090 Montpellier, France; (M.B.); (C.B.)
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5
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MIR172d Is Required for Floral Organ Identity and Number in Tomato. Int J Mol Sci 2021; 22:ijms22094659. [PMID: 33925088 PMCID: PMC8124722 DOI: 10.3390/ijms22094659] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/21/2021] [Accepted: 04/26/2021] [Indexed: 01/29/2023] Open
Abstract
MicroRNA172 (miR172) functions as a central regulator of flowering time and flower development by post-transcriptional repression of APETALA2-LIKE transcription factors. In the model crop Solanum lycopersicum (tomato), the miR172 family is still poorly annotated and information about the functions of specific members is lacking. Here, de-novo prediction of tomato miR172 coding loci identified seven genes (SlMIR172a-g), that code for four unique species of miR172 (sly-miR172). During reproductive development, sly-miR172s are differentially expressed, with sly-miR172c and sly-miR172d being the most abundant members in developing flowers, and are predicted to guide the cleavage of eight APETALA2-LIKE transcription factors. By CRISPR-Cas9 co-targeting of SlMIR172c and SlMIR172d we have generated a battery of loss-of-function and hypomorphic mutants (slmir172c-dCR). The slmir172c-dCR plants developed normal shoot but their flowers displayed graded floral organ abnormalities. Whereas slmir172cCR loss-of-function caused only a slight greening of petals and stamens, hypomorphic and loss-of-function slmir172dCR alleles were associated with the conversion of petals and stamens to sepaloids, which were produced in excess. Interestingly, the degrees of floral organ identity alteration and proliferation were directly correlated with the reduction in sly-miR172d activity. These results suggest that sly-miR172d regulates in a dose-dependent manner floral organ identity and number, likely by negatively regulating its APETALA2-like targets.
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6
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Computational identification of maize miRNA and their gene targets involved in biotic and abiotic stresses. J Biosci 2020. [DOI: 10.1007/s12038-020-00106-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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7
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Base-Pairing Requirements for Small RNA-Mediated Gene Silencing of Recessive Self-Incompatibility Alleles in Arabidopsis halleri. Genetics 2020; 215:653-664. [PMID: 32461267 DOI: 10.1534/genetics.120.303351] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 05/20/2020] [Indexed: 11/18/2022] Open
Abstract
Small noncoding RNAs are central regulators of genome activity and stability. Their regulatory function typically involves sequence similarity with their target sites, but understanding the criteria by which they specifically recognize and regulate their targets across the genome remains a major challenge in the field, especially in the face of the diversity of silencing pathways involved. The dominance hierarchy among self-incompatibility alleles in Brassicaceae is controlled by interactions between a highly diversified set of small noncoding RNAs produced by dominant S-alleles and their corresponding target sites on recessive S-alleles. By controlled crosses, we created numerous heterozygous combinations of S-alleles in Arabidopsis halleri and developed an real-time quantitative PCR assay to compare allele-specific transcript levels for the pollen determinant of self-incompatibility (SCR). This provides the unique opportunity to evaluate the precise base-pairing requirements for effective transcriptional regulation of this target gene. We found strong transcriptional silencing of recessive SCR alleles in all heterozygote combinations examined. A simple threshold model of base pairing for the small RNA-target interaction captures most of the variation in SCR transcript levels. For a subset of S-alleles, we also measured allele-specific transcript levels of the determinant of pistil specificity (SRK), and found sharply distinct expression dynamics throughout flower development between SCR and SRK In contrast to SCR, both SRK alleles were expressed at similar levels in the heterozygote genotypes examined, suggesting no transcriptional control of dominance for this gene. We discuss the implications for the evolutionary processes associated with the origin and maintenance of the dominance hierarchy among self-incompatibility alleles.
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8
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Svoboda P. Key Mechanistic Principles and Considerations Concerning RNA Interference. FRONTIERS IN PLANT SCIENCE 2020; 11:1237. [PMID: 32903622 PMCID: PMC7438612 DOI: 10.3389/fpls.2020.01237] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 07/28/2020] [Indexed: 05/03/2023]
Abstract
Canonical RNAi, one of the so-called RNA-silencing mechanisms, is defined as sequence-specific RNA degradation induced by long double-stranded RNA (dsRNA). RNAi occurs in four basic steps: (i) processing of long dsRNA by RNase III Dicer into small interfering RNA (siRNA) duplexes, (ii) loading of one of the siRNA strands on an Argonaute protein possessing endonucleolytic activity, (iii) target recognition through siRNA basepairing, and (iv) cleavage of the target by the Argonaute's endonucleolytic activity. This basic pathway diversified and blended with other RNA silencing pathways employing small RNAs. In some organisms, RNAi is extended by an amplification loop employing an RNA-dependent RNA polymerase, which generates secondary siRNAs from targets of primary siRNAs. Given the high specificity of RNAi and its presence in invertebrates, it offers an opportunity for highly selective pest control. The aim of this text is to provide an introductory overview of key mechanistic aspects of RNA interference for understanding its potential and constraints for its use in pest control.
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9
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Blyuss KB, Fatehi F, Tsygankova VA, Biliavska LO, Iutynska GO, Yemets AI, Blume YB. RNAi-Based Biocontrol of Wheat Nematodes Using Natural Poly-Component Biostimulants. FRONTIERS IN PLANT SCIENCE 2019; 10:483. [PMID: 31057585 PMCID: PMC6479188 DOI: 10.3389/fpls.2019.00483] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Accepted: 03/28/2019] [Indexed: 06/09/2023]
Abstract
With the growing global demands on sustainable food production, one of the biggest challenges to agriculture is associated with crop losses due to parasitic nematodes. While chemical pesticides have been quite successful in crop protection and mitigation of damage from parasites, their potential harm to humans and environment, as well as the emergence of nematode resistance, have necessitated the development of viable alternatives to chemical pesticides. One of the most promising and targeted approaches to biocontrol of parasitic nematodes in crops is that of RNA interference (RNAi). In this study we explore the possibility of using biostimulants obtained from metabolites of soil streptomycetes to protect wheat (Triticum aestivum L.) against the cereal cyst nematode Heterodera avenae by means of inducing RNAi in wheat plants. Theoretical models of uptake of organic compounds by plants, and within-plant RNAi dynamics, have provided us with useful insights regarding the choice of routes for delivery of RNAi-inducing biostimulants into plants. We then conducted in planta experiments with several streptomycete-derived biostimulants, which have demonstrated the efficiency of these biostimulants at improving plant growth and development, as well as in providing resistance against the cereal cyst nematode. Using dot blot hybridization we demonstrate that biostimulants trigger a significant increase of the production in plant cells of si/miRNA complementary with plant and nematode mRNA. Wheat germ cell-free experiments show that these si/miRNAs are indeed very effective at silencing the translation of nematode mRNA having complementary sequences, thus reducing the level of nematode infestation and improving plant resistance to nematodes. Thus, we conclude that natural biostimulants produced from metabolites of soil streptomycetes provide an effective tool for biocontrol of wheat nematode.
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Affiliation(s)
| | - Farzad Fatehi
- Department of Mathematics, University of Sussex, Brighton, United Kingdom
| | - Victoria A. Tsygankova
- Department of Chemistry of Bioactive Nitrogen-Containing Heterocyclic Compounds, Institute of Bioorganic Chemistry and Petrochemistry, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Liudmyla O. Biliavska
- Department of General and Soil Microbiology, Zabolotny Institute of Microbiology and Virology, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Galyna O. Iutynska
- Department of General and Soil Microbiology, Zabolotny Institute of Microbiology and Virology, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Alla I. Yemets
- Department of Cell Biology and Biotechnology, Institute of Food Biotechnology and Genomics, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Yaroslav B. Blume
- Department of Genomics and Molecular Biotechnology, Institute of Food Biotechnology and Genomics, National Academy of Sciences of Ukraine, Kyiv, Ukraine
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10
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Hanif Q, Farooq M, Amin I, Mansoor S, Zhang Y, Khan QM. In silico identification of conserved miRNAs and their selective target gene prediction in indicine (Bos indicus) cattle. PLoS One 2018; 13:e0206154. [PMID: 30365525 PMCID: PMC6203363 DOI: 10.1371/journal.pone.0206154] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 10/08/2018] [Indexed: 12/28/2022] Open
Abstract
The modern cattle was domesticated from aurochs, sharing its physiological traits into two subspecies Bos taurus and Bos indicus. MicroRNAs (miRNAs) are a class of non-coding short RNAs of ~22nt which have a key role in the regulation of many cellular and physiological processes in the animal. The current study was aimed to predict and annotate the potential mutations in indicine miRNAs throughout the genome using de novo and homology-based in silico approaches. Genome-wide mapping was performed in available indicine assembly by the homology-based approach and 768 miRNAs were recovered out of 808 reported taurine miRNAs belonging to 521 unique mature miRNA families. While 42 precursors were dropped due to lack of secondary miRNA structure, increasing stringency or decreasing similarity between the two genomes' miRNA. Increasing tendency of miRNAs incidence was observed on chr5, chr7, chr8, chr12 and chr21 with 19 polycistronic miRNA within 1-kilobase distance throughout the indicine genome. Notably, 12 miRNAs showed copy number variation. Eighteen miRNAs showed a mutation in their mature sequences in which eight were found in their seed region. Whilst in de novo based approach, 12 novel potential miRNAs on Y chromosome in indicine cattle along with a new miRNA (bind-miR-1264) on chrX were found. The final data set is annotated and explains the impending target genes that are responsible for enhanced immunity, heat tolerance and disease tolerance regulation in indicine. The study conforms to better understanding and perceptive approach towards indicine genome.
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Affiliation(s)
- Quratulain Hanif
- Key Laboratory of Animal Genetics and Breeding and Reproduction of Ministry of Agriculture, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
- Bioinformatics and Computational Biology Laboratory, National Institute for Biotechnology and Genetic Engineering, (NIBGE), Faisalabad, Pakistan
- Pakistan Institute of Engineering and Applied Sciences, Islamabad, PK
| | - Muhammad Farooq
- Bioinformatics and Computational Biology Laboratory, National Institute for Biotechnology and Genetic Engineering, (NIBGE), Faisalabad, Pakistan
| | - Imran Amin
- Bioinformatics and Computational Biology Laboratory, National Institute for Biotechnology and Genetic Engineering, (NIBGE), Faisalabad, Pakistan
| | - Shahid Mansoor
- Bioinformatics and Computational Biology Laboratory, National Institute for Biotechnology and Genetic Engineering, (NIBGE), Faisalabad, Pakistan
| | - Yi Zhang
- Key Laboratory of Animal Genetics and Breeding and Reproduction of Ministry of Agriculture, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Qaiser Mahmood Khan
- Environmental Toxicology Laboratory, National Institute for Biotechnology and Genetic Engineering, (NIBGE), Faisalabad, Pakistan
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11
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Li Z, Xu R, Li N. MicroRNAs from plants to animals, do they define a new messenger for communication? Nutr Metab (Lond) 2018; 15:68. [PMID: 30302122 PMCID: PMC6167836 DOI: 10.1186/s12986-018-0305-8] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 09/21/2018] [Indexed: 12/13/2022] Open
Abstract
MicroRNAs (miRNAs), a class of single-stranded non-coding RNA of about 22 nucleotides, are potent regulators of gene expression existing in both plants and animals. Recent studies showed that plant miRNAs could enter mammalian bloodstream via gastrointestinal tract, through which access a variety of tissues and cells of recipients to exert therapeutic effects. This intriguing phenomenon indicates that miRNAs of diet/plant origin may act as a new class of bioactive ingredients communicating with mammalian systems. In this review, in order to pinpoint the reason underlying discrepancies of miRNAs transmission from diet/plant to animals, the pathways that generate miRNAs and machineries involved in the functions of miRNAs in both kingdoms were outlined and compared. Then, the current controversies concerning cross-kingdom regulations and the potential mechanisms responsible for absorption and transfer of diet/plant-derived miRNAs were interpreted. Furthermore, the hormone-like action of miRNAs and the intricate interplay between miRNAs and hormones were implicated. Finally, how these findings may impact nutrition and medicine were briefly discussed.
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Affiliation(s)
- Zhiqing Li
- 1State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Tsinghua University, Beijing, 100005 People's Republic of China
| | - Ruodan Xu
- 2Institute of Basic Theory for Chinese Medicine, China Academy of Chinese Medical Sciences, Beijing, 100700 People's Republic of China.,3Department of Engineering, Aarhus University, 8000 Aarhus, Denmark
| | - Ning Li
- 2Institute of Basic Theory for Chinese Medicine, China Academy of Chinese Medical Sciences, Beijing, 100700 People's Republic of China
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12
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Axtell MJ, Meyers BC. Revisiting Criteria for Plant MicroRNA Annotation in the Era of Big Data. THE PLANT CELL 2018; 30:272-284. [PMID: 29343505 PMCID: PMC5868703 DOI: 10.1105/tpc.17.00851] [Citation(s) in RCA: 231] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
MicroRNAs (miRNAs) are ∼21-nucleotide-long regulatory RNAs that arise from endonucleolytic processing of hairpin precursors. Many function as essential posttranscriptional regulators of target mRNAs and long noncoding RNAs. Alongside miRNAs, plants also produce large numbers of short interfering RNAs (siRNAs), which are distinguished from miRNAs primarily by their biogenesis (typically processed from long double-stranded RNA instead of single-stranded hairpins) and functions (typically via roles in transcriptional regulation instead of posttranscriptional regulation). Next-generation DNA sequencing methods have yielded extensive data sets of plant small RNAs, resulting in many miRNA annotations. However, it has become clear that many miRNA annotations are questionable. The sheer number of endogenous siRNAs compared with miRNAs has been a major factor in the erroneous annotation of siRNAs as miRNAs. Here, we provide updated criteria for the confident annotation of plant miRNAs, suitable for the era of "big data" from DNA sequencing. The updated criteria emphasize replication and the minimization of false positives, and they require next-generation sequencing of small RNAs. We argue that improved annotation systems are needed for miRNAs and all other classes of plant small RNAs. Finally, to illustrate the complexities of miRNA and siRNA annotation, we review the evolution and functions of miRNAs and siRNAs in plants.
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Affiliation(s)
- Michael J Axtell
- The Pennsylvania State University, Department of Biology and Huck Institutes of the Life Sciences, University Park, Pennsylvania 16802
| | - Blake C Meyers
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
- University of Missouri-Columbia, Division of Plant Sciences, Columbia, Missouri 65211
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14
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Zheng Z, Reichel M, Deveson I, Wong G, Li J, Millar AA. Target RNA Secondary Structure Is a Major Determinant of miR159 Efficacy. PLANT PHYSIOLOGY 2017; 174:1764-1778. [PMID: 28515145 PMCID: PMC5490886 DOI: 10.1104/pp.16.01898] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 05/13/2017] [Indexed: 05/20/2023]
Abstract
In plants, microRNA (miRNA)-target complementarity has long been considered the predominant factor determining the silencing outcome of the miRNA-target interaction, although the efficacy of such interactions have rarely been appraised in plants. Here, we perform in planta silencing efficacy assays on seven Arabidopsis MYB genes, all of which contain conserved miR159-binding sites of analogous complementarity. These genes were found to be differentially silenced by miR159; MYB81, MYB97, MYB101, MYB104, and DUO1 were all poorly silenced, whereas MYB33 and MYB65 were strongly silenced. Curiously, this is consistent with previous genetic analysis defining MYB33 and MYB65 as the major functional targets of miR159. Neither the free energy of miR159-target complementarity, nor miRNA binding site accessibility, as determined by flanking region AU content, could fully explain the discrepancy of miR159 silencing efficacy. Instead, we found that MYB33 and MYB65 were both predicted to contain a distinctive RNA secondary structure abutting the miR159 binding site. The structure is composed of two stem-loops (SLs) that are predicted to form in MYB33/65 homologs of species as evolutionary distant as gymnosperms. Functional analysis found that the RNA structure in MYB33 correlated with strong silencing efficacy; introducing mutations to disrupt either SL attenuated miR159 efficacy, while introducing complementary mutations to restore the SLs, but not the sequence, restored strong miR159-mediated silencing. Therefore, it appears that this RNA secondary structure demarcates MYB33/65 as sensitive targets of miR159, which underpins the narrow functional specificity of Arabidopsis miR159.
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Affiliation(s)
- Zihui Zheng
- Division of Plant Science, Research School of Biology, The Australian National University, Canberra ACT 2601, Australia
| | - Marlene Reichel
- Division of Plant Science, Research School of Biology, The Australian National University, Canberra ACT 2601, Australia
| | - Ira Deveson
- Division of Plant Science, Research School of Biology, The Australian National University, Canberra ACT 2601, Australia
| | - Gigi Wong
- Division of Plant Science, Research School of Biology, The Australian National University, Canberra ACT 2601, Australia
| | - Junyan Li
- Division of Plant Science, Research School of Biology, The Australian National University, Canberra ACT 2601, Australia
| | - Anthony A Millar
- Division of Plant Science, Research School of Biology, The Australian National University, Canberra ACT 2601, Australia
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Paces J, Nic M, Novotny T, Svoboda P. Literature review of baseline information to support the risk assessment of RNAi‐based GM plants. ACTA ACUST UNITED AC 2017. [PMCID: PMC7163844 DOI: 10.2903/sp.efsa.2017.en-1246] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Jan Paces
- Institute of Molecular Genetics of the Academy of Sciences of the Czech Republic (IMG)
| | | | | | - Petr Svoboda
- Institute of Molecular Genetics of the Academy of Sciences of the Czech Republic (IMG)
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16
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Zhou J, Deng K, Cheng Y, Zhong Z, Tian L, Tang X, Tang A, Zheng X, Zhang T, Qi Y, Zhang Y. CRISPR-Cas9 Based Genome Editing Reveals New Insights into MicroRNA Function and Regulation in Rice. FRONTIERS IN PLANT SCIENCE 2017; 8:1598. [PMID: 28955376 PMCID: PMC5602353 DOI: 10.3389/fpls.2017.01598] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Accepted: 08/31/2017] [Indexed: 05/18/2023]
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs that play important roles in plant development and stress responses. Loss-of-function analysis of miRNA genes has been traditionally challenging due to lack of appropriate knockout tools. In this study, single miRNA genes (OsMIR408 and OsMIR528) and miRNA gene families (miR815a/b/c and miR820a/b/c) in rice were targeted by CRISPR-Cas9. We showed single strand conformation polymorphism (SSCP) is a more reliable method than restriction fragment length polymorphism (RFLP) for identifying CRISPR-Cas9 generated mutants. Frequencies of targeted mutagenesis among regenerated T0 lines ranged from 48 to 89% at all tested miRNA target sites. In the case of miRNA528, three independent guide RNAs (gRNAs) all generated biallelic mutations among confirmed mutant lines. When targeted by two gRNAs, miRNA genes were readily to be deleted at a frequency up to 60% in T0 rice lines. Thus, we demonstrate CRISPR-Cas9 is an effective tool for knocking out plant miRNAs. Single-base pair (bp) insertion/deletion mutations (indels) in mature miRNA regions can lead to the generation of functionally redundant miRNAs. Large deletions at either the mature miRNA or the complementary miRNA* were found to readily abolish miRNA function. Utilizing mutants of OsMIR408 and OsMIR528, we find that knocking out a single miRNA can result in expression profile changes of many other seemingly unrelated miRNAs. In a case study on OsMIR528, we reveal it is a positive regulator in salt stress. Our work not only provides empirical guidelines on targeting miRNAs with CRISPR-Cas9, but also brings new insights into miRNA function and complex cross-regulation in rice.
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Affiliation(s)
- Jianping Zhou
- Department of Biotechnology, School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of ChinaChengdu, China
| | - Kejun Deng
- Department of Biotechnology, School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of ChinaChengdu, China
| | - Yan Cheng
- Department of Biotechnology, School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of ChinaChengdu, China
| | - Zhaohui Zhong
- Department of Biotechnology, School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of ChinaChengdu, China
| | - Li Tian
- Department of Biotechnology, School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of ChinaChengdu, China
| | - Xu Tang
- Department of Biotechnology, School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of ChinaChengdu, China
| | - Aiting Tang
- Department of Biotechnology, School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of ChinaChengdu, China
| | - Xuelian Zheng
- Department of Biotechnology, School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of ChinaChengdu, China
| | - Tao Zhang
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou UniversityYangzhou, China
| | - Yiping Qi
- Department of Plant Science and Landscape Architecture, University of MarylandCollege Park, MD, United States
- Institute for Bioscience and Biotechnology Research, University of MarylandRockville, MD, United States
- *Correspondence: Yiping Qi
| | - Yong Zhang
- Department of Biotechnology, School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of ChinaChengdu, China
- Yong Zhang
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17
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Lahmy S, Pontier D, Bies-Etheve N, Laudié M, Feng S, Jobet E, Hale CJ, Cooke R, Hakimi MA, Angelov D, Jacobsen SE, Lagrange T. Evidence for ARGONAUTE4-DNA interactions in RNA-directed DNA methylation in plants. Genes Dev 2016; 30:2565-2570. [PMID: 27986858 PMCID: PMC5204349 DOI: 10.1101/gad.289553.116] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 11/17/2016] [Indexed: 12/29/2022]
Abstract
RNA polymerase V (Pol V) long noncoding RNAs (lncRNAs) have been proposed to guide ARGONAUTE4 (AGO4) to chromatin in RNA-directed DNA methylation (RdDM) in plants. Here, we provide evidence, based on laser UV-assisted zero-length cross-linking, for functionally relevant AGO4-DNA interaction at RdDM targets. We further demonstrate that Pol V lncRNAs or the act of their transcription are required to lock Pol V holoenzyme into a stable DNA-bound state that allows AGO4 recruitment via redundant glycine-tryptophan/tryptophan-glycine AGO hook motifs present on both Pol V and its associated factor, SPT5L. We propose a model in which AGO4-DNA interaction could be responsible for the unique specificities of RdDM.
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Affiliation(s)
- Sylvie Lahmy
- Laboratoire Génome et Développement des Plantes (LGDP), UMR5096, Centre National de la Recherche Scientifique (CNRS), Université de Perpignan via Domitia (UPVD), 66860 Perpignan, France
| | - Dominique Pontier
- Laboratoire Génome et Développement des Plantes (LGDP), UMR5096, Centre National de la Recherche Scientifique (CNRS), Université de Perpignan via Domitia (UPVD), 66860 Perpignan, France
| | - Natacha Bies-Etheve
- Laboratoire Génome et Développement des Plantes (LGDP), UMR5096, Centre National de la Recherche Scientifique (CNRS), Université de Perpignan via Domitia (UPVD), 66860 Perpignan, France
| | - Michèle Laudié
- Laboratoire Génome et Développement des Plantes (LGDP), UMR5096, Centre National de la Recherche Scientifique (CNRS), Université de Perpignan via Domitia (UPVD), 66860 Perpignan, France
| | - Suhua Feng
- Department of Molecular, Cell, and Developmental Biology, University of California at Los Angeles, Los Angeles, California 90095, USA.,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Edouard Jobet
- Laboratoire Génome et Développement des Plantes (LGDP), UMR5096, Centre National de la Recherche Scientifique (CNRS), Université de Perpignan via Domitia (UPVD), 66860 Perpignan, France
| | - Christopher J Hale
- Department of Molecular, Cell, and Developmental Biology, University of California at Los Angeles, Los Angeles, California 90095, USA.,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California at Los Angeles, Los Angeles, California 90095, USA.,Department of Pathology, Center for Precision Diagnostics, University of Washington, Seattle, Washington 98195, USA
| | - Richard Cooke
- Laboratoire Génome et Développement des Plantes (LGDP), UMR5096, Centre National de la Recherche Scientifique (CNRS), Université de Perpignan via Domitia (UPVD), 66860 Perpignan, France
| | - Mohamed-Ali Hakimi
- Institute for Advanced Biosciences (IAB), UMR5309, CNRS, U1209, Institut National de la Santé et de la Recherche Médicale (INSERM), Grenoble Alpes University, 38000 Grenoble, France
| | - Dimitar Angelov
- Laboratoire de Biologie et Modélisation de la Cellule (LBMC), UMR 5239, CNRS/École Normale Supérieure de Lyon (ENSL)/Université Claude Bernard Lyon 1 (UCBL), 69007 Lyon, France.,Institut NeuroMyogène (INMG), UMR 5310, CNRS/UCBL/ENSL, 69007 Lyon, France
| | - Steven E Jacobsen
- Department of Molecular, Cell, and Developmental Biology, University of California at Los Angeles, Los Angeles, California 90095, USA.,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California at Los Angeles, Los Angeles, California 90095, USA.,Howard Hughes Medical Institute, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Thierry Lagrange
- Laboratoire Génome et Développement des Plantes (LGDP), UMR5096, Centre National de la Recherche Scientifique (CNRS), Université de Perpignan via Domitia (UPVD), 66860 Perpignan, France
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18
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Wang F, Johnson NR, Coruh C, Axtell MJ. Genome-wide analysis of single non-templated nucleotides in plant endogenous siRNAs and miRNAs. Nucleic Acids Res 2016; 44:7395-405. [PMID: 27207877 PMCID: PMC5009732 DOI: 10.1093/nar/gkw457] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 04/26/2016] [Accepted: 05/11/2016] [Indexed: 11/15/2022] Open
Abstract
Plant small RNAs are subject to various modifications. Previous reports revealed widespread 3' modifications (truncations and non-templated tailing) of plant miRNAs when the 2'-O-methyltransferase HEN1 is absent. However, non-templated nucleotides in plant heterochromatic siRNAs have not been deeply studied, especially in wild-type plants. We systematically studied non-templated nucleotide patterns in plant small RNAs by analyzing small RNA sequencing libraries from Arabidopsis, tomato, Medicago, rice, maize and Physcomitrella Elevated rates of non-templated nucleotides were observed at the 3' ends of both miRNAs and endogenous siRNAs from wild-type specimens of all species. 'Off-sized' small RNAs, such as 25 and 23 nt siRNAs arising from loci dominated by 24 nt siRNAs, often had very high rates of 3'-non-templated nucleotides. The same pattern was observed in all species that we studied. Further analysis of 24 nt siRNA clusters in Arabidopsis revealed distinct patterns of 3'-non-templated nucleotides of 23 nt siRNAs arising from heterochromatic siRNA loci. This pattern of non-templated 3' nucleotides on 23 nt siRNAs is not affected by loss of known small RNA 3'-end modifying enzymes, and may result from modifications added to longer heterochromatic siRNA precursors.
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Affiliation(s)
- Feng Wang
- Intercollege Plant Biology PhD Program, Huck Institutes of the Life Sciences, Penn State University, University Park, PA 16802, USA Department of Biology, Penn State University, University Park, PA 16802, USA
| | - Nathan R Johnson
- Intercollege Plant Biology PhD Program, Huck Institutes of the Life Sciences, Penn State University, University Park, PA 16802, USA Department of Biology, Penn State University, University Park, PA 16802, USA
| | - Ceyda Coruh
- Intercollege Plant Biology PhD Program, Huck Institutes of the Life Sciences, Penn State University, University Park, PA 16802, USA Department of Biology, Penn State University, University Park, PA 16802, USA
| | - Michael J Axtell
- Intercollege Plant Biology PhD Program, Huck Institutes of the Life Sciences, Penn State University, University Park, PA 16802, USA Department of Biology, Penn State University, University Park, PA 16802, USA
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19
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Shriram V, Kumar V, Devarumath RM, Khare TS, Wani SH. MicroRNAs As Potential Targets for Abiotic Stress Tolerance in Plants. FRONTIERS IN PLANT SCIENCE 2016; 7:817. [PMID: 27379117 PMCID: PMC4906921 DOI: 10.3389/fpls.2016.00817] [Citation(s) in RCA: 174] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 05/25/2016] [Indexed: 05/19/2023]
Abstract
The microRNAs (miRNAs) are small (20-24 nt) sized, non-coding, single stranded riboregulator RNAs abundant in higher organisms. Recent findings have established that plants assign miRNAs as critical post-transcriptional regulators of gene expression in sequence-specific manner to respond to numerous abiotic stresses they face during their growth cycle. These small RNAs regulate gene expression via translational inhibition. Usually, stress induced miRNAs downregulate their target mRNAs, whereas, their downregulation leads to accumulation and function of positive regulators. In the past decade, investigations were mainly aimed to identify plant miRNAs, responsive to individual or multiple environmental factors, profiling their expression patterns and recognizing their roles in stress responses and tolerance. Altered expressions of miRNAs implicated in plant growth and development have been reported in several plant species subjected to abiotic stress conditions such as drought, salinity, extreme temperatures, nutrient deprivation, and heavy metals. These findings indicate that miRNAs may hold the key as potential targets for genetic manipulations to engineer abiotic stress tolerance in crop plants. This review is aimed to provide recent updates on plant miRNAs, their biogenesis and functions, target prediction and identification, computational tools and databases available for plant miRNAs, and their roles in abiotic stress-responses and adaptive mechanisms in major crop plants. Besides, the recent case studies for overexpressing the selected miRNAs for miRNA-mediated enhanced abiotic stress tolerance of transgenic plants have been discussed.
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Affiliation(s)
- Varsha Shriram
- Department of Botany, Prof. Ramkrishna More Arts, Commerce and Science College, Savitribai Phule Pune UniversityPune, India
| | - Vinay Kumar
- Department of Biotechnology, Modern College of Arts, Science and Commerce, Savitribai Phule Pune UniversityPune, India
- *Correspondence: Vinay Kumar
| | - Rachayya M. Devarumath
- Molecular Biology and Genetic Engineering Section, Vasantdada Sugar InstitutePune, India
| | - Tushar S. Khare
- Department of Biotechnology, Modern College of Arts, Science and Commerce, Savitribai Phule Pune UniversityPune, India
| | - Shabir H. Wani
- Division of Genetics and Plant Breeding, Faculty of Agriculture WADURA, Sher-e-Kashmir University of Agricultural Sciences and TechnologyKashmir, India
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