Host-induced gene silencing and spray-induced gene silencing for crop protection against viruses.

2021 ◽  
pp. 72-85
Author(s):  
Angela Ricci ◽  
Silvia Sabbadini ◽  
Laura Miozzi ◽  
Bruno Mezzetti ◽  
Emanuela Noris
Keyword(s):  
Gene Silencing ◽  
Plant Pathogens ◽  
Crop Protection ◽  
Plant Defence ◽  
Transcriptional Gene Silencing ◽  
Target Sequence ◽  
Sequence Specificity ◽  
Rna Molecules ◽  
Political Concern ◽  
Post Transcriptional Gene Silencing

Abstract Since the beginning of agriculture, plant virus diseases have been a strong challenge for farming. Following its discovery at the very beginning of the 1990s, the RNA interference (RNAi) mechanism has been widely studied and exploited as an integrative tool to obtain resistance to viruses in several plant species, with high target-sequence specificity. In this chapter, we describe and review the major aspects of host-induced gene silencing (HIGS), as one of the possible plant defence methods, using genetic engineering techniques. In particular, we focus our attention on the use of RNAi-based gene constructs to introduce stable resistance in host plants against viral diseases, by triggering post-transcriptional gene silencing (PTGS). Recently, spray-induced gene silencing (SIGS), consisting of the topical application of small RNA molecules to plants, has been explored as an alternative tool to the stable integration of RNAi-based gene constructs in plants. SIGS has great and innovative potential for crop defence against different plant pathogens and pests and is expected to raise less public and political concern, as it does not alter the genetic structure of the plant.

Host-induced gene silencing and spray-induced gene silencing for crop protection against viruses.

2021 ◽  
pp. 72-85
Author(s):  
Angela Ricci ◽  
Silvia Sabbadini ◽  
Laura Miozzi ◽  
Bruno Mezzetti ◽  
Emanuela Noris
Keyword(s):  
Gene Silencing ◽  
Plant Pathogens ◽  
Crop Protection ◽  
Plant Defence ◽  
Transcriptional Gene Silencing ◽  
Target Sequence ◽  
Sequence Specificity ◽  
Rna Molecules ◽  
Political Concern ◽  
Post Transcriptional Gene Silencing

Abstract Since the beginning of agriculture, plant virus diseases have been a strong challenge for farming. Following its discovery at the very beginning of the 1990s, the RNA interference (RNAi) mechanism has been widely studied and exploited as an integrative tool to obtain resistance to viruses in several plant species, with high target-sequence specificity. In this chapter, we describe and review the major aspects of host-induced gene silencing (HIGS), as one of the possible plant defence methods, using genetic engineering techniques. In particular, we focus our attention on the use of RNAi-based gene constructs to introduce stable resistance in host plants against viral diseases, by triggering post-transcriptional gene silencing (PTGS). Recently, spray-induced gene silencing (SIGS), consisting of the topical application of small RNA molecules to plants, has been explored as an alternative tool to the stable integration of RNAi-based gene constructs in plants. SIGS has great and innovative potential for crop defence against different plant pathogens and pests and is expected to raise less public and political concern, as it does not alter the genetic structure of the plant.

scholarly journals Dual-layer transposon repression in heads of Drosophila melanogaster

2018 ◽  
Author(s):  
Marius van den Beek ◽  
Bruno da Silva ◽  
Juliette Pouch ◽  
Mohammed el amine Ali Chaouche ◽  
Clément Carré ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Silencing ◽  
Rna Extraction ◽  
Transcript Abundance ◽  
Transcriptional Gene Silencing ◽  
Loss Of Function ◽  
Wild Type ◽  
Rna Molecules ◽  
Post Transcriptional Gene Silencing ◽  
Ping Pong

AbstractpiRNA-mediated repression of transposable elements (TE) in the germline limits the accumulation of heritable mutations caused by their transposition in the genome. It is not clear whether the piRNA pathway plays a functional role in adult, non-gonadal tissues in Drosophila melanogaster. To address this question, we first analyzed the small RNA content of adult Drosophila melanogaster heads. We found that varying amount of piRNA-sized, ping-pong positive molecules in heads correlates with contamination by gonadal tissue during RNA extraction, suggesting that most of piRNAs detected in head sequencing libraries originate from gonads. We next sequenced the heads of wild type and piwi mutants to address whether piwi loss of function would affect the low amount of piRNA-sized, ping-pong negative molecules that are still detected in heads hand-checked to avoid gonadal contamination. We find that loss of piwi does not affect significantly these 24-28 RNA molecules. Instead, we observe increased siRNA levels against the majority of Drosophila transposable element families. To determine the effect of this siRNA level change on transposon expression, we sequenced the transcriptome of wild type, piwi, dicer-2 and piwi, dicer-2 double-mutant fly heads. We find that RNA expression levels of the majority of TE families in piwi or dicer-2 mutants remain unchanged and that TE transcript abundance increases significantly only in piwi, dicer-2 double-mutants. These results lead us to suggest a dual-layer model for TE repression in adult somatic tissues. Piwi-mediated transcriptional gene silencing (TGS) established during embryogenesis constitutes the first layer of TE repression whereas Dicer-2-dependent siRNA-mediated post-transcriptional gene silencing (PTGS) provide a backup mechanism to repress TEs that escape silencing by piwi-mediated TGS.

The long hand of the small RNAs reaches into several levels of gene regulation

2004 ◽  
Vol 82 (4) ◽  
pp. 472-481 ◽  
Author(s):  
Tony Nolan ◽  
Carlo Cogoni
Keyword(s):  
Gene Silencing ◽  
Small Rnas ◽  
Developmental Regulation ◽  
Transcriptional Gene Silencing ◽  
Rna Molecules ◽  
New Class ◽  
Post Transcriptional Gene Silencing ◽  
Wide Range ◽  
Cellular Defence ◽  
Genomic Organisation

Small RNA molecules such as siRNAs and miRNAs represent a new class of molecules that have been implicated in a wide range of diverse gene silencing phenomena. It is now becoming clear that these two similar molecules share several common features in both their biogenesis and their mechanism of action. Thus, the siRNA and miRNA pathways may have evolved from a common ancestral mechanism that has diverged to play important roles in developmental regulation, genomic organisation, and cellular defence against foreign nucleic acids.Key words: miRNA, siRNA, post-transcriptional gene silencing, RNAi, heterochromatin.

RNA duplexes in transcriptional regulation

2010 ◽  
Vol 1 (3-4) ◽  
pp. 285-296
Author(s):  
Sanjay Swaminathan ◽  
Chantelle L. Hood ◽  
Kazuo Suzuki ◽  
Anthony D. Kelleher
Keyword(s):  
Gene Expression ◽  
Transcriptional Regulation ◽  
Gene Silencing ◽  
Gene Activation ◽  
Current Status ◽  
Transcriptional Gene Silencing ◽  
Regulatory Pathways ◽  
Rna Molecules ◽  
Post Transcriptional Gene Silencing ◽  
Rna Duplexes

AbstractTranscriptional regulation by small RNA molecules, including small interfering RNA and microRNA, has emerged as an important gene expression modulator. The regulatory pathways controlling gene expression, post-transcriptional gene silencing and transcriptional gene silencing (TGS) have been demonstrated in yeast, plants and more recently in human cells. In this review, we discuss the currents models of transcriptional regulation and the main components of the RNA-induced silencing complex and RNA-induced transcriptional silencing complex machinery, as well as confounding off-target effects and gene activation. We also discuss RNA-mediated TGS within the NF-κB motif of the human immunodeficiency virus type 1 5′ long tandem repeat promoter region and the associated epigenetic modifications. Finally, we outline the current RNA interference (RNAi) delivery methods and describe the current status of human trials investigating potential RNAi therapeutics for several human diseases.

scholarly journals Viroids as a Tool to Study RNA-Directed DNA Methylation in Plants

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1187
Author(s):  
Michael Wassenegger ◽  
Athanasios Dalakouras
Keyword(s):  
Dna Methylation ◽  
Rna Interference ◽  
Gene Silencing ◽  
Plant Cells ◽  
Transcriptional Gene Silencing ◽  
Rnai Machinery ◽  
Double Stranded Rna ◽  
Post Transcriptional Gene Silencing ◽  
Cumulative Amount

Viroids are plant pathogenic, circular, non-coding, single-stranded RNAs (ssRNAs). Members of the Pospiviroidae family replicate in the nucleus of plant cells through double-stranded RNA (dsRNA) intermediates, thus triggering the host’s RNA interference (RNAi) machinery. In plants, the two RNAi pillars are Post-Transcriptional Gene Silencing (PTGS) and RNA-directed DNA Methylation (RdDM), and the latter has the potential to trigger Transcriptional Gene Silencing (TGS). Over the last three decades, the employment of viroid-based systems has immensely contributed to our understanding of both of these RNAi facets. In this review, we highlight the role of Pospiviroidae in the discovery of RdDM, expound the gradual elucidation through the years of the diverse array of RdDM’s mechanistic details and propose a revised RdDM model based on the cumulative amount of evidence from viroid and non-viroid systems.

scholarly journals Epigenetic Changes in Host Ribosomal DNA Promoter Induced by an Asymptomatic Plant Virus Infection

Biology ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 91 ◽  
Author(s):  
Miryam Pérez-Cañamás ◽  
Elizabeth Hevia ◽  
Carmen Hernández
Keyword(s):  
Gene Silencing ◽  
Ribosomal Dna ◽  
Plant Virus ◽  
Dna Methyltransferase ◽  
Cytosine Methylation ◽  
De Novo ◽  
Methylation Pattern ◽  
Transcriptional Gene Silencing ◽  
Post Transcriptional Gene Silencing ◽  
The Impact

DNA cytosine methylation is one of the main epigenetic mechanisms in higher eukaryotes and is considered to play a key role in transcriptional gene silencing. In plants, cytosine methylation can occur in all sequence contexts (CG, CHG, and CHH), and its levels are controlled by multiple pathways, including de novo methylation, maintenance methylation, and demethylation. Modulation of DNA methylation represents a potentially robust mechanism to adjust gene expression following exposure to different stresses. However, the potential involvement of epigenetics in plant-virus interactions has been scarcely explored, especially with regard to RNA viruses. Here, we studied the impact of a symptomless viral infection on the epigenetic status of the host genome. We focused our attention on the interaction between Nicotiana benthamiana and Pelargonium line pattern virus (PLPV, family Tombusviridae), and analyzed cytosine methylation in the repetitive genomic element corresponding to ribosomal DNA (rDNA). Through a combination of bisulfite sequencing and RT-qPCR, we obtained data showing that PLPV infection gives rise to a reduction in methylation at CG sites of the rDNA promoter. Such a reduction correlated with an increase and decrease, respectively, in the expression levels of some key demethylases and of MET1, the DNA methyltransferase responsible for the maintenance of CG methylation. Hypomethylation of rDNA promoter was associated with a five-fold augmentation of rRNA precursor levels. The PLPV protein p37, reported as a suppressor of post-transcriptional gene silencing, did not lead to the same effects when expressed alone and, thus, it is unlikely to act as suppressor of transcriptional gene silencing. Collectively, the results suggest that PLPV infection as a whole is able to modulate host transcriptional activity through changes in the cytosine methylation pattern arising from misregulation of methyltransferases/demethylases balance.

MicroRNA expression in infertile men: its alterations and effects

Zygote ◽  
2019 ◽  
Vol 27 (05) ◽  
pp. 263-271 ◽  
Author(s):  
Maryam Kiani ◽  
Mohammad Salehi ◽  
Asghar Mogheiseh
Keyword(s):  
Male Infertility ◽  
Testicular Biopsy ◽  
Transcriptional Gene Silencing ◽  
Mirna Regulation ◽  
Altered Expression ◽  
Diagnostic Biomarkers ◽  
Rna Molecules ◽  
Non Invasive ◽  
Post Transcriptional Gene Silencing ◽  
Different Types

SummaryInfertility is an important reproductive health problem, and male infertility is especially important in more than half of infertility cases. Due to the importance of genetic factors in this condition, analysis of semen alone is not enough to recognize men with idiopathic infertility. A molecular non-invasive investigation is necessary to gain valuable information. Currently, microRNAs (miRNAs) are being used as non-invasive diagnostic biomarkers. miRNAs, single-stranded non-coding RNA molecules, act as post-transcriptional gene silencing regulators either by inhibition or repression of translation. Changes in the regulation of miRNAs have been investigated in several different types of male infertility, therefore the biological role of miRNA and gene targets has been defined. The purpose of this study was to review recent research on the altered expression of miRNA in semen, sperm, and testicular biopsy samples in infertile males with different types of unexplained infertility. Changes in miRNA regulation were investigated using microarray and the miRNA levels were confirmed by real-time qRT-PCR. This review explains why creating a non-invasive diagnostic method for male infertility is necessary and how changes in miRNA expression can be used as new diagnostic biomarkers in patients with differing spermatogenic and histopathologic injury.

scholarly journals The Impact of Dietary Compounds in Functional Foods on MicroRNAs Expression

2021 ◽  
Author(s):  
Wittaya Chaiwangyen
Keyword(s):  
Messenger Rna ◽  
Positive Impact ◽  
Biologically Active ◽  
Transcriptional Gene Silencing ◽  
Cellular Mirnas ◽  
Rna Molecules ◽  
Post Transcriptional Gene Silencing ◽  
Molecular Machinery ◽  
Different Origins ◽  
The Impact

MicroRNAs (miRNAs) are a class of non-coding endogenous RNA molecules that are involved in post-transcriptional gene silencing via binding to their target messenger RNA, leading to mRNA degradation or translational repression. MicroRNAs can be modulated by several factors including hormones, transcription factors, and dietary compounds. These biologically active compounds have positive impact on the progression of human pathology including non-communicable diseases, which indicating that administration of diet may have potential as therapeutic agents in modulating the risk of chronic diseases. Interestingly, evidence emerging in recent years suggests that dietary miRNAs can be absorbed in human circulation, modulated human gene expression and biological functions. The exploitation of the miRNA functioning within different origins, cellular miRNAs and dietary miRNAs will help us to understand the molecular machinery as well as the regulatory mechanisms involved in fundamentally important biological processes. Therefore, this knowledge may be applied of natural bioactive compounds in preventive or therapeutic approaches.

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