scholarly journals RNAi-Mediated Control of Lepidopteran Pests of Important Crop Plants

2021 ◽  
Author(s):  
Shipra Saxena ◽  
Sneha Yogindran ◽  
Manmohan Arya ◽  
Yogita Sharma ◽  
Chandra Pal Singh
Keyword(s):  
Gene Silencing ◽  
Target Gene ◽  
Insect Pests ◽  
Crop Plants ◽  
Stem Loop ◽  
Rna Molecules ◽  
Lepidopteran Pests ◽  
Important Crop ◽  
Post Transcriptional Gene Silencing ◽  
Precursor Rna

Insects as pests destroy annually an estimated 18–20% of the crop production worldwide. Caterpillars, the larval stage of moths, are the major pests of agricultural products owing to their voracious feeding habits. In the past few decades, the potent methods of insect control, such as insecticides and Bt toxins, have been constrained as a result of health hazards, environmental issues, and development of resistance, after their prolonged application. Thus, there is need to find alternative options to improve plant protection strategies. Recently, RNA interference (RNAi), the post-transcriptional gene-silencing mechanism, has emerged as one of such a novel, sustainable, and environment friendly approaches for insect management and crop protection. RNAi technology relies on selection of a vital insect pest target gene and its expression as a double stranded RNA or stem-loop RNA molecule, which is recognized by the host RNAi machinery and processed into small interfering RNAs (siRNAs) or microRNAs (miRNAs). The siRNA/miRNA along with the RNA-induced silencing complex (RISC) binds to the complimentary mRNA and induce gene silencing at post-transcriptional level. With effective target-gene selection and transgenic plants expressing these precursor RNA molecules, insect pests of various crops have been efficiently managed. In this chapter, we discuss the basic mechanism of RNAi and its application in controlling lepidopteran pests of important crop plants.

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 Mining of miRNAs using Next Generation Sequencing (NGS) data generated for Okra (Abelmoschus esculentus)

2018 ◽  
Vol 13 (2) ◽  
pp. 137-145
Author(s):  
Rekha Gupta ◽  
M Gayathri ◽  
V Radhika ◽  
M Pichaimuthu ◽  
K V Ravishankar
Keyword(s):  
Gene Expression ◽  
Mirna Family ◽  
Abelmoschus Esculentus ◽  
Stem Loop ◽  
Rna Molecules ◽  
Non Coding Rna ◽  
Precursor Rna ◽  
Next Generation Sequencing Ngs ◽  
Ngs Data ◽  
Generation Sequencing

MicroRNAs (miRNAs) are small, highly conserved non-coding RNA molecules involved in theregulation of gene expression in eukaryotes. Gene expression involves post-transcriptionalgene regulation by miRNAs. miRNAs are formed from precursor RNA molecules that fold intoa stem loop secondary structure. The mature miRNA is one end of the precursor miRNA,defined by the cut from ‘Drosha’ on either the 5’ or 3’ arm. In this study, we have used abioinformatics approach to identify miRNAs in 3,361 contigs obtained from partial genomesequence data of Abelmoschus esculentus (okra) sequenced by NGS technology. Using C-miiand psRNA Target tools, we identified two miRNAs and their target RNAs for which a regulatorymiRNA binding has been verified. Their targets consisted of transcription factors involved ingrowth and development, gene regulation and metabolism. Phylogenetic analysis of the newlyidentified miRNA family has been done to compare their level of conservation with respect tothe other members of the plant kingdom.

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.

968: Gelsolin Gene Silencing Involving Unusual Chromatin Structures and a Novel Stem Loop Structure of the Promoter Region in Human Bladder Cancer

2004 ◽  
Vol 171 (4S) ◽  
pp. 256-257
Author(s):  
Kazunori Haga ◽  
Ataru Sazawa ◽  
Toru Harabayashi ◽  
Nobuo Shinohara ◽  
Minoru Nomoto ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Gene Silencing ◽  
Promoter Region ◽  
Loop Structure ◽  
Human Bladder Cancer ◽  
Human Bladder ◽  
Stem Loop ◽  
Stem Loop Structure

Artificial microRNA (amiRNA) induced gene silencing in alfalfa (Medicago sativa)

Botany ◽  
2013 ◽  
Vol 91 (2) ◽  
pp. 117-122 ◽  
Author(s):  
Julian C. Verdonk ◽  
Michael L. Sullivan
Keyword(s):  
Gene Silencing ◽  
Medicago Sativa ◽  
Target Gene ◽  
Target Genes ◽  
Mirna Precursor ◽  
Crop Species ◽  
Forage Crop ◽  
Ribonucleic Acids ◽  
Endogenous Gene ◽  
Medicago Sativa L

Gene silencing is a powerful technique that allows the study of the function of specific genes by selectively reducing their transcription. Several different approaches can be used, however they all have in common the artificial generation of single stranded small ribonucleic acids (RNAs) that are utilized by the endogenous gene silencing machinery of the organism. Artificial microRNAs (amiRNA) can be used to very specifically target genes for silencing because only a short sequence of 21 nucleotides of the gene of interest is used. Gene silencing via amiRNA has been developed for Arabidopsis thaliana (L.) Heynh. and rice using endogenous microRNA (miRNA) precursors and has been shown to also work effectively in other dicot species using the arabidopsis miRNA precursor. Here, we demonstrate that the arabidopsis miR319 precursor can be used to silence genes in the important forage crop species alfalfa (Medicago sativa L.) by silencing the expression of a transgenic beta-glucuronidase (GUSPlus) target gene.

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