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Kallemi P, Verret F, Andronis C, Ioannidis N, Glampedakis N, Kotzabasis K, Kalantidis K. Stress-related transcriptomic changes associated with GFP transgene expression and active transgene silencing in plants. Sci Rep 2024; 14:13314. [PMID: 38858413 PMCID: PMC11164987 DOI: 10.1038/s41598-024-63527-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/29/2024] [Indexed: 06/12/2024] Open
Abstract
Plants respond to biotic and abiotic stress by activating and interacting with multiple defense pathways, allowing for an efficient global defense response. RNA silencing is a conserved mechanism of regulation of gene expression directed by small RNAs important in acquired plant immunity and especially virus and transgene repression. Several RNA silencing pathways in plants are crucial to control developmental processes and provide protection against abiotic and biotic stresses as well as invasive nucleic acids such as viruses and transposable elements. Various notable studies have shed light on the genes, small RNAs, and mechanisms involved in plant RNA silencing. However, published research on the potential interactions between RNA silencing and other plant stress responses is limited. In the present study, we tested the hypothesis that spreading and maintenance of systemic post-transcriptional gene silencing (PTGS) of a GFP transgene are associated with transcriptional changes that pertain to non-RNA silencing-based stress responses. To this end, we analyzed the structure and function of the photosynthetic apparatus and conducted whole transcriptome analysis in a transgenic line of Nicotiana benthamiana that spontaneously initiates transgene silencing, at different stages of systemic GFP-PTGS. In vivo analysis of chlorophyll a fluorescence yield and expression levels of key photosynthetic genes indicates that photosynthetic activity remains unaffected by systemic GFP-PTGS. However, transcriptomic analysis reveals that spreading and maintenance of GFP-PTGS are associated with transcriptional reprogramming of genes that are involved in abiotic stress responses and pattern- or effector-triggered immunity-based stress responses. These findings suggest that systemic PTGS may affect non-RNA-silencing-based defense pathways in N. benthamiana, providing new insights into the complex interplay between different plant stress responses.
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Affiliation(s)
- Paraskevi Kallemi
- Department of Biology, University of Crete, 70013, Heraklion, Greece
| | - Frederic Verret
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013, Heraklion, Greece
| | - Christos Andronis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013, Heraklion, Greece
| | | | | | | | - Kriton Kalantidis
- Department of Biology, University of Crete, 70013, Heraklion, Greece.
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013, Heraklion, Greece.
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2
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Silvestri A, Bansal C, Rubio-Somoza I. After silencing suppression: miRNA targets strike back. TRENDS IN PLANT SCIENCE 2024:S1360-1385(24)00119-5. [PMID: 38811245 DOI: 10.1016/j.tplants.2024.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 04/26/2024] [Accepted: 05/08/2024] [Indexed: 05/31/2024]
Abstract
Within the continuous tug-of-war between plants and microbes, RNA silencing stands out as a key battleground. Pathogens, in their quest to colonize host plants, have evolved a diverse arsenal of silencing suppressors as a common strategy to undermine the host's RNA silencing-based defenses. When RNA silencing malfunctions in the host, genes that are usually targeted and silenced by microRNAs (miRNAs) become active and can contribute to the reprogramming of host cells, providing an additional defense mechanism. A growing body of evidence suggests that miRNAs may act as intracellular sensors to enable a rapid response to pathogen threats. Herein we review how plant miRNA targets play a crucial role in immune responses against different pathogens.
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Affiliation(s)
- Alessandro Silvestri
- Molecular Reprogramming and Evolution Laboratory, Centre for Research in Agricultural Genomics, 08193 Barcelona, Spain
| | - Chandni Bansal
- Molecular Reprogramming and Evolution Laboratory, Centre for Research in Agricultural Genomics, 08193 Barcelona, Spain
| | - Ignacio Rubio-Somoza
- Molecular Reprogramming and Evolution Laboratory, Centre for Research in Agricultural Genomics, 08193 Barcelona, Spain; Consejo Superior de Investigaciones Científicas (CSIC), Barcelona 08001, Spain.
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Ali S, Tyagi A, Mir ZA. Plant Immunity: At the Crossroads of Pathogen Perception and Defense Response. PLANTS (BASEL, SWITZERLAND) 2024; 13:1434. [PMID: 38891243 PMCID: PMC11174815 DOI: 10.3390/plants13111434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 05/21/2024] [Accepted: 05/21/2024] [Indexed: 06/21/2024]
Abstract
Plants are challenged by different microbial pathogens that affect their growth and productivity. However, to defend pathogen attack, plants use diverse immune responses, such as pattern-triggered immunity (PTI), effector-triggered immunity (ETI), RNA silencing and autophagy, which are intricate and regulated by diverse signaling cascades. Pattern-recognition receptors (PRRs) and nucleotide-binding leucine-rich repeat (NLR) receptors are the hallmarks of plant innate immunity because they can detect pathogen or related immunogenic signals and trigger series of immune signaling cascades at different cellular compartments. In plants, most commonly, PRRs are receptor-like kinases (RLKs) and receptor-like proteins (RLPs) that function as a first layer of inducible defense. In this review, we provide an update on how plants sense pathogens, microbe-associated molecular patterns (PAMPs or MAMPs), and effectors as a danger signals and activate different immune responses like PTI and ETI. Further, we discuss the role RNA silencing, autophagy, and systemic acquired resistance as a versatile host defense response against pathogens. We also discuss early biochemical signaling events such as calcium (Ca2+), reactive oxygen species (ROS), and hormones that trigger the activation of different plant immune responses. This review also highlights the impact of climate-driven environmental factors on host-pathogen interactions.
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Affiliation(s)
- Sajad Ali
- Department of Biotechnology, Yeungnam University, Gyeongsan 38541, Republic of Korea;
| | - Anshika Tyagi
- Department of Biotechnology, Yeungnam University, Gyeongsan 38541, Republic of Korea;
| | - Zahoor Ahmad Mir
- Department of Plant Science and Agriculture, University of Manitoba, Winnipeg, MB R2M 0TB, Canada;
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Escalante C, Sanz-Saez A, Jacobson A, Otulak-Kozieł K, Kozieł E, Balkcom KS, Zhao C, Conner K. Plant virus transmission during seed development and implications to plant defense system. FRONTIERS IN PLANT SCIENCE 2024; 15:1385456. [PMID: 38779063 PMCID: PMC11109449 DOI: 10.3389/fpls.2024.1385456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 04/24/2024] [Indexed: 05/25/2024]
Abstract
Most plants produce large amounts of seeds to disperse their progeny in the environment. Plant viruses have evolved to avoid plant resistance mechanisms and use seeds for their dispersal. The presence of plant pathogenic viruses in seeds and suppression of plant host defenses is a major worldwide concern for producers and seed companies because undetected viruses in the seed can represent a significant threat to yield in many economically important crops. The vertical transmission of plant viruses occurs directly through the embryo or indirectly by getting in pollen grains or ovules. Infection of plant viruses during the early development of the seed embryo can result in morphological or genetic changes that cause poor seed quality and, more importantly, low yields due to the partial or ubiquitous presence of the virus at the earliest stages of seedling development. Understanding transmission of plant viruses and the ability to avoid plant defense mechanisms during seed embryo development will help identify primary inoculum sources, reduce virus spread, decrease severity of negative effects on plant health and productivity, and facilitate the future of plant disease management during seed development in many crops. In this article, we provide an overview of the current knowledge and understanding of plant virus transmission during seed embryo development, including the context of host-virus interaction.
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Affiliation(s)
- Cesar Escalante
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States
| | - Alvaro Sanz-Saez
- Department of Crop Soil and Environmental Sciences, Auburn University, Auburn, AL, United States
| | - Alana Jacobson
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States
| | - Katarzyna Otulak-Kozieł
- Institute of Biology, Department of Botany, Warsaw University of Life Sciences, Warsaw, Poland
| | - Edmund Kozieł
- Institute of Biology, Department of Botany, Warsaw University of Life Sciences, Warsaw, Poland
| | - Kipling S. Balkcom
- The United States Department of Agriculture - Agricultural Research Service (USDA-ARS) National Soil Dynamics Lab, Auburn, AL, United States
| | - Chaoyang Zhao
- The United States Department of Agriculture - Agricultural Research Service (USDA-ARS) National Soil Dynamics Lab, Auburn, AL, United States
| | - Kassie Conner
- Alabama Cooperative Extension, Auburn University, Auburn, AL, United States
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5
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Lukhovitskaya N, Brown K, Hua L, Pate AE, Carr JP, Firth AE. A novel ilarvirus protein CP-RT is expressed via stop codon readthrough and suppresses RDR6-dependent RNA silencing. PLoS Pathog 2024; 20:e1012034. [PMID: 38814986 PMCID: PMC11166343 DOI: 10.1371/journal.ppat.1012034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 06/11/2024] [Accepted: 05/03/2024] [Indexed: 06/01/2024] Open
Abstract
Ilarviruses are a relatively understudied but important group of plant RNA viruses that includes a number of crop pathogens. Their genomes comprise three RNA segments encoding two replicase subunits, movement protein, coat protein (CP), and (in some ilarvirus subgroups) a protein that suppresses RNA silencing. Here we report that, in many ilarviruses, RNA3 encodes an additional protein (termed CP-RT) as a result of ribosomal readthrough of the CP stop codon into a short downstream readthrough (RT) ORF. Using asparagus virus 2 as a model, we find that CP-RT is expressed in planta where it functions as a weak suppressor of RNA silencing. CP-RT expression is essential for persistent systemic infection in leaves and shoot apical meristem. CP-RT function is dependent on a putative zinc-finger motif within RT. Replacing the asparagus virus 2 RT with the RT of an ilarvirus from a different subgroup restored the ability to establish persistent infection. These findings open up a new avenue for research on ilarvirus silencing suppression, persistent meristem invasion and vertical transmission.
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Affiliation(s)
- Nina Lukhovitskaya
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Katherine Brown
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Lei Hua
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Adrienne E. Pate
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - John P. Carr
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Andrew E. Firth
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
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Kang YC, Yeh SD, Chen TC. Leucine 127 of Cucurbit Chlorotic Yellows Virus P22 Is Crucial for Its RNA Silencing Suppression Activity and Pathogenicity. PHYTOPATHOLOGY 2024; 114:813-822. [PMID: 37913633 DOI: 10.1094/phyto-07-23-0227-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
Plant viruses produce particular suppressors to antagonize the host defense response of RNA silencing to establish infection. Cucurbit chlorotic yellows virus (CCYV), a member of the genus Crinivirus of the family Closteroviridae, severely damages the production of economically essential cucurbits worldwide. Here, we used the attenuated zucchini yellow mosaic virus (ZYMV) vector ZAC to express individual coding sequences, including CP, CPm, P25, and P22, of a Taiwan CCYV isolate (CCYV-TW) to identify their possible roles as pathogenicity determinants. ZAC is an HC-Pro function mutant that lacks the ability of local lesion induction on Chenopodium quinoa leaves and induces mild mottling followed by recovery on its natural host zucchini squash plants. Only the recombinant expressing CCYV-TW P22 complemented the effect of ZAC HC-Pro dysfunction, causing more severe symptoms on zucchini squash plants and restoring lesion formation on C. quinoa leaves, with lesions forming faster than those generated by the wild-type ZYMV. This suggests that CCYV-TW P22 is a virulence enhancer. Sequence analysis of criniviral P22s revealed the presence of four conserved leucine residues (L10, L17, L84, and L127) and one conserved lysine residue (K185). The five P22 residues conserved among the CCYV isolates and the P22 orthologs of two other criniviruses were each substituted with alanine in CCYV-TW P22 to investigate its ability to suppress RNA silencing and pathogenicity. The results provide new insights into CCYV-P22, showing that the L127 residue of P22 is indispensable for maintaining its stability in RNA silencing suppression and essential for virulence enhancement.
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Affiliation(s)
- Ya-Chi Kang
- Department of Medical Laboratory Science and Biotechnology, Asia University, Wufeng, Taichung 41354, Taiwan
- Department of Plant Pathology, National Chung Hsing University, Taichung 40227, Taiwan
| | - Shyi-Dong Yeh
- Department of Plant Pathology, National Chung Hsing University, Taichung 40227, Taiwan
- Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan
| | - Tsung-Chi Chen
- Department of Medical Laboratory Science and Biotechnology, Asia University, Wufeng, Taichung 41354, Taiwan
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Dahan J, Orellana GE, Wald KB, Wenninger EJ, Cooper WR, Karasev AV. Bactericera cockerelli Picorna-like Virus and Three New Viruses Found Circulating in Populations of Potato/Tomato Psyllids ( Bactericera cockerelli). Viruses 2024; 16:415. [PMID: 38543780 PMCID: PMC10975263 DOI: 10.3390/v16030415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 02/28/2024] [Accepted: 03/06/2024] [Indexed: 04/01/2024] Open
Abstract
An investigation of viruses circulating in populations of field and laboratory potato/tomato psyllids (Bactericera cockerelli) was conducted using high-throughput sequencing (HTS) technology and conventional RT-PCR. Three new viruses were discovered: one from the family Tymoviridae and two from the family Solemoviridae. A tymo-like virus sequence represented a nearly complete 6843 nt genome of a virus named Bactericera cockerelli tymo-like virus (BcTLV) that spanned five open reading frames (ORFs) which encoded RNA-dependent RNA polymerase (RdRP), helicase, protease, methyltransferase, and a capsid protein. Phylogenetic analyses placed the RdRP of BcTLV inside a divergent lineage of the viruses from the family Tymoviridae found in insect and plant hosts in a sister clade to the genera Tymovirus, Marafivirus, and Maculavirus. Four solemo-like virus sequences were identified in the HTS outputs, representing two new viruses. One virus found only in field-collected psyllids and named Bactericera cockerelli solemo-like virus 1 (BcSLV-1) had a 5479 nt genome which spanned four ORFs encoding protease and RdRP. Three solemo-like sequences displayed 87.4-99.7% nucleotide sequence identity among themselves, representing variants or strains of the same virus named Bactericera cockerelli solemo-like virus 2 (BcSLV-2). The genome of BcSLV-2 spanned only two ORFs that encoded a protease and an RdRP. Phylogenetic analysis placed the RdRPs of BcSLV-1 and BcSLV-2 in two separate lineages as sister clades to viruses from the genus Sobemovirus found in plant hosts. All three new psyllid viruses were found circulating in psyllids collected from potato fields in southern Idaho along with a previously identified Bactericera cockerelli picorna-like virus. Any possible role of the three viruses in controlling populations of the field psyllids remains to be elucidated.
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Affiliation(s)
- Jennifer Dahan
- Department of Entomology, Plant Pathology, and Nematology, University of Idaho, 875 Perimeter Drive, MS 2329, Moscow, ID 83844-2329, USA; (J.D.); (G.E.O.); (K.B.W.)
| | - Gardenia E. Orellana
- Department of Entomology, Plant Pathology, and Nematology, University of Idaho, 875 Perimeter Drive, MS 2329, Moscow, ID 83844-2329, USA; (J.D.); (G.E.O.); (K.B.W.)
| | - Kaleigh B. Wald
- Department of Entomology, Plant Pathology, and Nematology, University of Idaho, 875 Perimeter Drive, MS 2329, Moscow, ID 83844-2329, USA; (J.D.); (G.E.O.); (K.B.W.)
| | - Erik J. Wenninger
- Department of Entomology, Plant Pathology, and Nematology, and Kimberly Research and Extension Center, University of Idaho, Kimberly, ID 83341-5082, USA;
| | - W. Rodney Cooper
- USDA-ARS, Temperate Tree Fruit and Vegetable Research Unit, Wapato, WA 98951, USA;
| | - Alexander V. Karasev
- Department of Entomology, Plant Pathology, and Nematology, University of Idaho, 875 Perimeter Drive, MS 2329, Moscow, ID 83844-2329, USA; (J.D.); (G.E.O.); (K.B.W.)
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Zhang Y, Tian X, Xu H, Zhan B, Zhou C, Li S, Zhang Z. Knockout of SlDCL2b attenuates the resistance of tomato to potato spindle tuber viroid infection. MOLECULAR PLANT PATHOLOGY 2024; 25:e13441. [PMID: 38462774 PMCID: PMC10925824 DOI: 10.1111/mpp.13441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 01/18/2024] [Accepted: 02/18/2024] [Indexed: 03/12/2024]
Abstract
RNA interference, or RNA silencing, is an important defence mechanism against viroid infection in plants. Plants encode multiple DICER-LIKE (DCL) proteins that are key components of the RNA silencing pathway. However, the roles of different DCLs in defence responses against viroid infection remain unclear. Here, we determined the function of tomato DCL2b (SlDCL2b) in defence responses against potato spindle tuber viroid (PSTVd) infection using SlDCL2b loss-of-function tomato mutant plants. Compared with wild-type plants, mutant plants were more susceptible to PSTVd infection, developing more severe symptoms earlier and accumulating higher levels of PSTVd RNAs. Moreover, we verified the feedback mechanism for the regulation of SlDCL2b expression by miR6026. Functional blocking of tomato miR6026, by expressing its target mimics, can enhance resistance to PSTVd infection in tomato plants. These findings deepen the current understanding of RNAi-based resistance against viroid infection and provide a potentially new strategy for viroid control.
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Affiliation(s)
- Yuhong Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection (IPP), Chinese Academy of Agricultural Sciences (CAAS)BeijingChina
| | - Xiaxia Tian
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection (IPP), Chinese Academy of Agricultural Sciences (CAAS)BeijingChina
- Citrus Research InstituteSouthwest UniversityChongqingChina
| | - Huiyuan Xu
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection (IPP), Chinese Academy of Agricultural Sciences (CAAS)BeijingChina
| | - Binhui Zhan
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection (IPP), Chinese Academy of Agricultural Sciences (CAAS)BeijingChina
| | - Changyong Zhou
- Citrus Research InstituteSouthwest UniversityChongqingChina
| | - Shifang Li
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection (IPP), Chinese Academy of Agricultural Sciences (CAAS)BeijingChina
| | - Zhixiang Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection (IPP), Chinese Academy of Agricultural Sciences (CAAS)BeijingChina
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Xu X, Lou Y, Liang K, Liu J, Wang Z, Chen B, Li W. The P2 nucleic acid binding protein of Sugarcane bacilliform virus is a viral pathogenic factor. PeerJ 2024; 12:e16982. [PMID: 38406282 PMCID: PMC10885806 DOI: 10.7717/peerj.16982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 01/30/2024] [Indexed: 02/27/2024] Open
Abstract
Background Saccharum spp. is the primary source of sugar and plays a significant role in global renewable bioenergy. Sugarcane bacilliform virus (SCBV) is one of the most important viruses infecting sugarcane, causing severe yield losses and quality degradation. It is of great significance to reveal the pathogenesis of SCBV and resistance breeding. However, little is known about the viral virulence factors or RNA silencing suppressors and the molecular mechanism of pathogenesis. Methods To systematically investigate the functions of the unknown protein P2 encoded by SCBV ORF2. Phylogenetic analysis was implemented to infer the evolutionary relationship between the P2 of SCBV and other badnaviruses. The precise subcellular localization of P2 was verified in the transient infiltrated Nicotiana benthamiana epidermal mesophyll cells and protoplasts using the Laser scanning confocal microscope (LSCM). The post-transcriptional gene silencing (PTGS) and transcriptional gene silencing (TGS) RNA silencing suppressor activity of P2 was analyzed, respectively. Furthermore, restriction digestion and RT-qPCR assays were conducted to verify the probable mechanism of P2 on repressing DNA methylation. To explore the pathogenicity of P2, a potato virus X-based viral vector was used to heterologously express SCBV P2 and the consequent H2O2 accumulation was detected by the 3,3'-diaminobenzidine (DAB) staining method. Results Phylogenetic analysis shows that SCBV has no obvious sequence similarity and low genetic relatedness to Badnavirus and Tungrovirus representatives. LSCM studies show that P2 is localized in both the cytoplasm and nucleus. Moreover, P2 is shown to be a suppressor of PTGS and TGS, which can not only repress ssRNA-induced gene silencing but also disrupt the host RNA-directed DNA methylation (RdDM) pathway. In addition, P2 can trigger an oxidative burst and cause typical hypersensitive-like response (HLR) necrosis in systemic leaves of N. benthamiana when expressed by PVX. Overall, our results laid a foundation for deciphering the molecular mechanism of SCBV pathogenesis and made progress for resistance breeding.
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Affiliation(s)
- Xiongbiao Xu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi key Laboratory of Sugarcane biology, Province and Ministry Co-sponsored Collaborative Innovation Center of Canesugar Industry, College of Agriculture, Guangxi University, Nanning, Guangxi, China
| | - Yinian Lou
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi key Laboratory of Sugarcane biology, Province and Ministry Co-sponsored Collaborative Innovation Center of Canesugar Industry, College of Agriculture, Guangxi University, Nanning, Guangxi, China
| | - Kaili Liang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi key Laboratory of Sugarcane biology, Province and Ministry Co-sponsored Collaborative Innovation Center of Canesugar Industry, College of Agriculture, Guangxi University, Nanning, Guangxi, China
| | - Jingying Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi key Laboratory of Sugarcane biology, Province and Ministry Co-sponsored Collaborative Innovation Center of Canesugar Industry, College of Agriculture, Guangxi University, Nanning, Guangxi, China
| | - Zhiyuan Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi key Laboratory of Sugarcane biology, Province and Ministry Co-sponsored Collaborative Innovation Center of Canesugar Industry, College of Agriculture, Guangxi University, Nanning, Guangxi, China
| | - Baoshan Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi key Laboratory of Sugarcane biology, Province and Ministry Co-sponsored Collaborative Innovation Center of Canesugar Industry, College of Agriculture, Guangxi University, Nanning, Guangxi, China
| | - Wenlan Li
- College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
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Leastro MO, Pallás V, Sánchez-Navarro JÁ. The capsid protein of citrus leprosis virus C shows a nuclear distribution and interacts with the nucleolar fibrillarin protein. Virus Res 2024; 340:199297. [PMID: 38070688 PMCID: PMC10758971 DOI: 10.1016/j.virusres.2023.199297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 11/29/2023] [Accepted: 12/06/2023] [Indexed: 01/05/2024]
Abstract
Brevipalpus-transmitted viruses (BTVs) have a significant negative economic impact on the citrus industry in Central and South America. Until now, only a few studies have explored the intracellular distribution and interaction of BTVs-encoded proteins with host factors, particularly for cileviruses, the main BTV responsible for the Citrus Leprosis (CL) disease. This study describes the nuclear localization of citrus leprosis virus C (CiLV-C) capsid protein (p29) and its interaction with the fibrillarin (Fib2) within the nucleolar compartment and cell cytoplasm. Our results, obtained by computer predictions and laser scanning confocal microscopy analyses, including colocalization and bimolecular fluorescence complementation (BiFC) approaches, revealed that a fraction of the p29 is localized in the nucleus and colocalizes with the Fib2 in both the nucleolus and cytosol. The nuclear localization of p29 correlated with a smaller nucleus size. Furthermore, co-immunoprecipitation (Co-IP) assays confirmed the interactions between p29 and Fib2. The implications of these findings for the functionalities of the cilevirus capsid protein are discussed.
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Affiliation(s)
- Mikhail Oliveira Leastro
- Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de Valencia-Consejo Superior de Investigaciones Científicas (CSIC), Valencia 46022, Spain.
| | - Vicente Pallás
- Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de Valencia-Consejo Superior de Investigaciones Científicas (CSIC), Valencia 46022, Spain
| | - Jesús Ángel Sánchez-Navarro
- Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de Valencia-Consejo Superior de Investigaciones Científicas (CSIC), Valencia 46022, Spain.
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11
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Naresh M, Purkayastha A, Dasgupta I. P4 protein of an Indian isolate of rice tungro bacilliform virus modulates gene silencing. Virus Genes 2024; 60:55-64. [PMID: 38055154 DOI: 10.1007/s11262-023-02039-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 11/09/2023] [Indexed: 12/07/2023]
Abstract
Plant hosts and their viral pathogens are engaged in a constant cycle of defense and counter-defense as part of a molecular arms race, principal among them being the plant RNAi defense and the viral RNAi suppressor counter-defense. Rice tungro bacilliform virus (RTBV), member of the family Caulimoviridae, genus Tungrovirus, species Tungrovirus oryzae, infects rice in South- and Southeast Asia and causes severe symptoms of stunting, yellow-orange discoloration and twisting of leaf tips. To better understand the possible counter-defensive roles of RTBV against the host RNAi defense system, we explored the ability of the P4 protein of an Indian isolate of RTBV to act as a possible modulator of RNAi. Using a transient silencing and silencing suppression assay in Nicotiana benthamiana, we show that P4 not only displays an RNAi suppressor function, but also potentially enhances RNAi. The results also suggests that the N-terminal 168 amino acid residues of P4 are sufficient to maintain RNAi suppressor activity. Taken together with the earlier reports this work strengthens the view that the P4 protein carries out RNAi suppressor and a potential RNAi enhancer function.
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Affiliation(s)
- Madhvi Naresh
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, 110021, India
| | - Arunima Purkayastha
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, 110021, India
| | - Indranil Dasgupta
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, 110021, India.
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12
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Hoffmann G, Incarbone M. A resilient bunch: stem cell antiviral immunity in plants. THE NEW PHYTOLOGIST 2024; 241:1415-1420. [PMID: 38058221 DOI: 10.1111/nph.19456] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 11/15/2023] [Indexed: 12/08/2023]
Abstract
Stem cells are vital for plant development and reproduction. The stem cells within shoot apical meristems are known to possess exceptionally effective antiviral defenses against pathogenic viruses which preclude their infection, yet how this is achieved remains poorly understood and scarcely investigated. In this Tansley Insight, we connect very recent experimental results with previous work to summarize the known molecular mechanisms determining stem cell antiviral immunity. More broadly, we attempt to define the viral features triggering immunity and the global consequences of virus infection in these essential cells. This brief article will highlight how these phenomena are fascinating, complex and often crucial for virus-host interactions, while emphasizing the potential for discovery in their investigation.
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Affiliation(s)
- Gesa Hoffmann
- Max Planck Institute of Molecular Plant Physiology (MPIMP), 1 Am Mühlenberg Strasse, 14476, Potsdam, Germany
| | - Marco Incarbone
- Max Planck Institute of Molecular Plant Physiology (MPIMP), 1 Am Mühlenberg Strasse, 14476, Potsdam, Germany
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Ye X, Ding D, Chen Y, Liu C, Li Z, Lou B, Zhou Y. Identification of RNA silencing suppressor encoded by citrus chlorotic dwarf-associated virus. Front Microbiol 2024; 15:1328289. [PMID: 38333582 PMCID: PMC10850569 DOI: 10.3389/fmicb.2024.1328289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 01/04/2024] [Indexed: 02/10/2024] Open
Abstract
Introduction Citrus chlorotic dwarf-associated virus (CCDaV) is an economically important citrus virus associated with leaf curling, deformation, and chlorosis found in China. Plants have evolved RNA silencing to defend against viral infections; however, the mechanism by which CCDaV suppresses RNA silencing in citrus remains unknown. Methods Six proteins encoded by CCDaV were ectopically expressed in Nicotiana benthamiana 16c using the pCHF3 vector to identify RNA-silencing suppression activities. Results V2 protein encoded by CCDaV suppressed local RNA silencing and systemic RNA silencing triggered by GFP RNA, but did not impede short-distance movement of the RNA silencing signal in N. benthamiana 16c. GFP fluorescence observations showed that the ability of V2 protein to suppress RNA silencing was weaker than tomato bushy stunt virus P19. Deletion analysis showed that the putative nuclear localization signal (NLS, 25-54 aa) was involved in the RNA silencing suppression activity of V2 protein. Furthermore, V2 protein cannot block dsRNA-triggered RNA silencing. The subcellular localization assay suggested that V2 protein was localized to nucleus of N. benthamiana. Conclusion Overall, the results of this study demonstrate that CCDaV-V2 acts as an activity of silencing suppression. This is the first reported RNA-silencing suppressor encoded by Citlodavirus and will be valuable in revealing the molecular mechanism of CCDaV infection.
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Affiliation(s)
- Xiao Ye
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City/Citrus Research Institute, Southwest University, Chongqing, China
| | - Dongdong Ding
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City/Citrus Research Institute, Southwest University, Chongqing, China
| | - Yuan Chen
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City/Citrus Research Institute, Southwest University, Chongqing, China
| | - Chuang Liu
- Lemon Industry Development Center, Anyue, Sichuan, China
| | - Zhongan Li
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City/Citrus Research Institute, Southwest University, Chongqing, China
| | - Binghai Lou
- Guangxi Citrus Breeding and Cultivation Research Center of Engineering Technology/Guangxi Academy of Specialty Crops, Guilin, Guangxi, China
| | - Yan Zhou
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City/Citrus Research Institute, Southwest University, Chongqing, China
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Yan D, Han K, Lu Y, Peng J, Rao S, Wu G, Liu Y, Chen J, Zheng H, Yan F. The nanovirus U2 protein suppresses RNA silencing via three conserved cysteine residues. MOLECULAR PLANT PATHOLOGY 2024; 25:e13394. [PMID: 37823358 PMCID: PMC10782648 DOI: 10.1111/mpp.13394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 09/19/2023] [Accepted: 09/19/2023] [Indexed: 10/13/2023]
Abstract
Nanoviruses have multipartite, circular, single-stranded DNA genomes and cause huge production losses in legumes and other crops. No viral suppressor of RNA silencing (VSR) has yet been reported from a member of the genus Nanovirus. Here, we demonstrate that the nanovirus U2 protein is a VSR. The U2 protein of milk vetch dwarf virus (MDV) suppressed the silencing of the green fluorescent protein (GFP) gene induced by single-stranded and double-stranded RNA, and the systemic spread of the GFP silencing signal. An electrophoretic mobility shift assay showed that the U2 protein was able to bind double-stranded 21-nucleotide small interfering RNA (siRNA). The cysteine residues at positions 43, 79 and 82 in the MDV U2 protein are critical to its nuclear localization, self-interaction and siRNA-binding ability, and were essential for its VSR activity. In addition, expression of the U2 protein via a potato virus X vector induced more severe necrosis symptoms in Nicotiana benthamiana leaves. The U2 proteins of other nanoviruses also acted as VSRs, and the three conserved cysteine residues were indispensable for their VSR activity.
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Affiliation(s)
- Dankan Yan
- College of Life SciencesFujian Agriculture and Forestry UniversityFuzhouChina
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products, Institute of Plant VirologyNingbo UniversityNingboChina
- Institute of Plant Protection and Agro‐Products SafetyAnhui Academy of Agricultural SciencesHefeiChina
| | - Kelei Han
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products, Institute of Plant VirologyNingbo UniversityNingboChina
- Institute of Plant Protection and Agro‐Products SafetyAnhui Academy of Agricultural SciencesHefeiChina
| | - Yuwen Lu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products, Institute of Plant VirologyNingbo UniversityNingboChina
| | - Jiejun Peng
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products, Institute of Plant VirologyNingbo UniversityNingboChina
| | - Shaofei Rao
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products, Institute of Plant VirologyNingbo UniversityNingboChina
| | - Guanwei Wu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products, Institute of Plant VirologyNingbo UniversityNingboChina
| | - Yong Liu
- Institute of Plant ProtectionHunan Academy of Agricultural SciencesChangshaChina
| | - Jianping Chen
- College of Life SciencesFujian Agriculture and Forestry UniversityFuzhouChina
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products, Institute of Plant VirologyNingbo UniversityNingboChina
| | - Hongying Zheng
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products, Institute of Plant VirologyNingbo UniversityNingboChina
| | - Fei Yan
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products, Institute of Plant VirologyNingbo UniversityNingboChina
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15
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Romero-Rodríguez B, Petek M, Jiao C, Križnik M, Zagorščak M, Fei Z, Bejarano ER, Gruden K, Castillo AG. Transcriptional and epigenetic changes during tomato yellow leaf curl virus infection in tomato. BMC PLANT BIOLOGY 2023; 23:651. [PMID: 38110861 PMCID: PMC10726652 DOI: 10.1186/s12870-023-04534-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 10/17/2023] [Indexed: 12/20/2023]
Abstract
BACKGROUND Geminiviruses are DNA plant viruses that cause highly damaging diseases affecting crops worldwide. During the infection, geminiviruses hijack cellular processes, suppress plant defenses, and cause a massive reprogramming of the infected cells leading to major changes in the whole plant homeostasis. The advances in sequencing technologies allow the simultaneous analysis of multiple aspects of viral infection at a large scale, generating new insights into the molecular mechanisms underlying plant-virus interactions. However, an integrative study of the changes in the host transcriptome, small RNA profile and methylome during a geminivirus infection has not been performed yet. Using a time-scale approach, we aim to decipher the gene regulation in tomato in response to the infection with the geminivirus, tomato yellow leaf curl virus (TYLCV). RESULTS We showed that tomato undergoes substantial transcriptional and post-transcriptional changes upon TYLCV infection and identified the main altered regulatory pathways. Interestingly, although the principal plant defense-related processes, gene silencing and the immune response were induced, this cannot prevent the establishment of the infection. Moreover, we identified extra- and intracellular immune receptors as targets for the deregulated microRNAs (miRNAs) and established a network for those that also produced phased secondary small interfering RNAs (phasiRNAs). On the other hand, there were no significant genome-wide changes in tomato methylome at 14 days post infection, the time point at which the symptoms were general, and the amount of viral DNA had reached its maximum level, but we were able to identify differentially methylated regions that could be involved in the transcriptional regulation of some of the differentially expressed genes. CONCLUSION We have conducted a comprehensive and reliable study on the changes at transcriptional, post-transcriptional and epigenetic levels in tomato throughout TYLCV infection. The generated genomic information is substantial for understanding the genetic, molecular and physiological changes caused by TYLCV infection in tomato.
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Affiliation(s)
- Beatriz Romero-Rodríguez
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM "La Mayora"), Universidad de Málaga-Consejo Superior de Investigaciones Científicas (UMA-CSIC), Boulevard Louis Pasteur, 49, Málaga, 29010, Spain
| | - Marko Petek
- Department of Biotechnology and Systems Biology, National Institute of Biology, Večna Pot 111, 1000, Ljubljana, Slovenia
| | - Chen Jiao
- Boyce Thompson Institute, Cornell University, Ithaca, NY, USA
- The Key Lab of Molecular Biology of Crop Pathogens and Insects of Ministry of Agriculture, The Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Maja Križnik
- Department of Biotechnology and Systems Biology, National Institute of Biology, Večna Pot 111, 1000, Ljubljana, Slovenia
| | - Maja Zagorščak
- Department of Biotechnology and Systems Biology, National Institute of Biology, Večna Pot 111, 1000, Ljubljana, Slovenia
| | - Zhangjun Fei
- Boyce Thompson Institute, Cornell University, Ithaca, NY, USA
| | - Eduardo R Bejarano
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM "La Mayora"), Universidad de Málaga-Consejo Superior de Investigaciones Científicas (UMA-CSIC), Boulevard Louis Pasteur, 49, Málaga, 29010, Spain
| | - Kristina Gruden
- Department of Biotechnology and Systems Biology, National Institute of Biology, Večna Pot 111, 1000, Ljubljana, Slovenia
| | - Araceli G Castillo
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM "La Mayora"), Universidad de Málaga-Consejo Superior de Investigaciones Científicas (UMA-CSIC), Boulevard Louis Pasteur, 49, Málaga, 29010, Spain.
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16
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Ullah I, Kamran M, Dunwell JM. Identification of a Novel Polerovirus in Cocoa ( Theobroma cacao) Germplasm and Development of Molecular Methods for Use in Diagnostics. Pathogens 2023; 12:1284. [PMID: 38003749 PMCID: PMC10674516 DOI: 10.3390/pathogens12111284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 10/23/2023] [Accepted: 10/25/2023] [Indexed: 11/26/2023] Open
Abstract
The cocoa crop (Theobroma cacao L.) is known to be a host for several badnaviruses, some of which cause severe disease, while others are asymptomatic. Recently, the first preliminary evidence has been published concerning the occurrence of a polerovirus in cacao. We report here the first near-complete genome sequence of cacao polerovirus (CaPV) by combining bioinformatic searches of cacao transcript databases, with cloning from the infected germplasm. The reported novel genome has all the genome features known for poleroviruses from other species. Pairwise identity analyses of RNA-dependent RNA polymerase and coat protein indicates < 60% similarity of CaPV with any reported poleroviruses; hence, we propose that the polerovirus isolate reported in this study is a novel polerovirus. The genome sequence information was also used to develop a multiplex RT-PCR assay, which was applied to screen a selected range of germplasms and to identify several infected clones. Although there is no evidence that this virus causes any severe disease, this new information, together with a robust diagnostic assay, are of strategic importance in developing protocols for the safe international transfer of cacao germplasms.
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Affiliation(s)
- Ihsan Ullah
- School of Agriculture, Policy and Development, University of Reading, Reading RG6 6EU, UK;
| | - Muhammad Kamran
- Plant Pathology Research Institute, Ayub Agricultural Research Institute, Faisalabad 38850, Pakistan;
| | - Jim M. Dunwell
- School of Agriculture, Policy and Development, University of Reading, Reading RG6 6EU, UK;
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17
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Naveed H, Islam W, Jafir M, Andoh V, Chen L, Chen K. A Review of Interactions between Plants and Whitefly-Transmitted Begomoviruses. PLANTS (BASEL, SWITZERLAND) 2023; 12:3677. [PMID: 37960034 PMCID: PMC10648457 DOI: 10.3390/plants12213677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 10/22/2023] [Accepted: 10/23/2023] [Indexed: 11/15/2023]
Abstract
The transmission of plant viruses from infected to healthy host plants is a process in which insects play a major role, using various transmission strategies. Environmental factors have an impact on the transmission of viruses and the subsequent development of infections or diseases. When viruses are successful, plant virus diseases can reach epidemic proportions. Many plants across different regions are vulnerable to viral infections transmitted by the whitefly vector. Begomoviruses, which are transmitted by whiteflies, represent a significant threat to agriculture worldwide. The review highlights the mechanisms of virus acquisition and transmission by whiteflies and explores the factors influencing these interactions. Understanding the impacts of these changes is crucial for managing the spread of pests and mitigating damage to crops. It underscores the need for continued research to elucidate the mechanisms driving plant-insect-virus interactions and to identify new approaches for sustainable pest management.
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Affiliation(s)
- Hassan Naveed
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China;
- School of Life Sciences, Jiangsu University, Zhenjiang 212013, China;
| | - Waqar Islam
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China;
| | - Muhammad Jafir
- Department of Ecology, School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China;
| | - Vivian Andoh
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China;
- School of Life Sciences, Jiangsu University, Zhenjiang 212013, China;
| | - Liang Chen
- School of Life Sciences, Jiangsu University, Zhenjiang 212013, China;
| | - Keping Chen
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China;
- School of Life Sciences, Jiangsu University, Zhenjiang 212013, China;
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18
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López-Márquez D, Del-Espino Á, Ruiz-Albert J, Bejarano ER, Brodersen P, Beuzón CR. Regulation of plant immunity via small RNA-mediated control of NLR expression. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:6052-6068. [PMID: 37449766 PMCID: PMC10575705 DOI: 10.1093/jxb/erad268] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 07/13/2023] [Indexed: 07/18/2023]
Abstract
Plants use different receptors to detect potential pathogens: membrane-anchored pattern recognition receptors (PRRs) activated upon perception of pathogen-associated molecular patterns (PAMPs) that elicit pattern-triggered immunity (PTI); and intracellular nucleotide-binding leucine-rich repeat proteins (NLRs) activated by detection of pathogen-derived effectors, activating effector-triggered immunity (ETI). The interconnections between PTI and ETI responses have been increasingly reported. Elevated NLR levels may cause autoimmunity, with symptoms ranging from fitness cost to developmental arrest, sometimes combined with run-away cell death, making accurate control of NLR dosage key for plant survival. Small RNA-mediated gene regulation has emerged as a major mechanism of control of NLR dosage. Twenty-two nucleotide miRNAs with the unique ability to trigger secondary siRNA production from target transcripts are particularly prevalent in NLR regulation. They enhance repression of the primary NLR target, but also bring about repression of NLRs only complementary to secondary siRNAs. We summarize current knowledge on miRNAs and siRNAs in the regulation of NLR expression with an emphasis on 22 nt miRNAs and propose that miRNA and siRNA regulation of NLR levels provides additional links between PTI and NLR defense pathways to increase plant responsiveness against a broad spectrum of pathogens and control an efficient deployment of defenses.
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Affiliation(s)
- Diego López-Márquez
- Department of Biology, University of Copenhagen, Copenhagen N, DK-2200, Denmark
| | - Ángel Del-Espino
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Depto. Biología Celular, Genética y Fisiología, Málaga, Spain
| | - Javier Ruiz-Albert
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Depto. Biología Celular, Genética y Fisiología, Málaga, Spain
| | - Eduardo R Bejarano
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Depto. Biología Celular, Genética y Fisiología, Málaga, Spain
| | - Peter Brodersen
- Department of Biology, University of Copenhagen, Copenhagen N, DK-2200, Denmark
| | - Carmen R Beuzón
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Depto. Biología Celular, Genética y Fisiología, Málaga, Spain
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19
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Sato Y, Suzuki N. Continued mycovirus discovery expanding our understanding of virus lifestyles, symptom expression, and host defense. Curr Opin Microbiol 2023; 75:102337. [PMID: 37343415 DOI: 10.1016/j.mib.2023.102337] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/16/2023] [Accepted: 05/17/2023] [Indexed: 06/23/2023]
Abstract
High-throughput sequencing technologies have greatly expanded the RNA virome in general and have led to an exponential increase in new fungal viruses, also known as mycoviruses. Mycoviruses are omnipresent in fungi and usually induce symptomless infections. Some mycoviruses infecting fungi pathogenic to plants, insects, and mammals are known to modify host virulence positively and negatively and attract particular interests. In addition, fungal viruses continue to provide intriguing research materials and themes that lead to discoveries of peculiar viruses as infectious entities and insights into virus evolution and diversity. In this review, we outline the diversity and neolifestyle of recently discovered fungal RNA viruses, and phenotypic alterations induced by them. Furthermore, we discuss recent advances in research regarding the fungal antiviral defense and viral counterdefense, which are closely associated with host phenotype alterations. We hope that this article will enhance understanding of the interesting and growing fungal virology field.
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Affiliation(s)
- Yukiyo Sato
- Institute for Plant Sciences, University of Cologne, Cologne, Germany
| | - Nobuhiro Suzuki
- Institute of Plant Science and Resources, Okayama University, 2-20-1 Chu-ou, Kurashiki, Okayama 710-0046, Japan.
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20
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Parperides E, El Mounadi K, Garcia‐Ruiz H. Induction and suppression of gene silencing in plants by nonviral microbes. MOLECULAR PLANT PATHOLOGY 2023; 24:1347-1356. [PMID: 37438989 PMCID: PMC10502822 DOI: 10.1111/mpp.13362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/22/2023] [Accepted: 05/23/2023] [Indexed: 07/14/2023]
Abstract
Gene silencing is a conserved mechanism in eukaryotes that dynamically regulates gene expression. In plants, gene silencing is critical for development and for maintenance of genome integrity. Additionally, it is a critical component of antiviral defence in plants, nematodes, insects, and fungi. To overcome gene silencing, viruses encode effectors that suppress gene silencing. A growing body of evidence shows that gene silencing and suppression of silencing are also used by plants during their interaction with nonviral pathogens such as fungi, oomycetes, and bacteria. Plant-pathogen interactions involve trans-kingdom movement of small RNAs into the pathogens to alter the function of genes required for their development and virulence. In turn, plant-associated pathogenic and nonpathogenic microbes also produce small RNAs that move trans-kingdom into host plants to disrupt pathogen defence through silencing of plant genes. The mechanisms by which these small RNAs move from the microbe to the plant remain poorly understood. In this review, we examine the roles of trans-kingdom small RNAs and silencing suppressors produced by nonviral microbes in inducing and suppressing gene silencing in plants. The emerging model is that gene silencing and suppression of silencing play critical roles in the interactions between plants and their associated nonviral microbes.
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Affiliation(s)
- Eric Parperides
- Department of Plant Pathology and Nebraska Center for VirologyUniversity of Nebraska‐LincolnLincolnNebraskaUSA
| | - Kaoutar El Mounadi
- Department of BiologyKutztown University of PennsylvaniaKutztownPennsylvaniaUSA
| | - Hernan Garcia‐Ruiz
- Department of Plant Pathology and Nebraska Center for VirologyUniversity of Nebraska‐LincolnLincolnNebraskaUSA
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21
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Spiegelman Z, Dinesh-Kumar SP. Breaking Boundaries: The Perpetual Interplay Between Tobamoviruses and Plant Immunity. Annu Rev Virol 2023; 10:455-476. [PMID: 37254097 DOI: 10.1146/annurev-virology-111821-122847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Plant viruses of the genus Tobamovirus cause significant economic losses in various crops. The emergence of new tobamoviruses such as the tomato brown rugose fruit virus (ToBRFV) poses a major threat to global agriculture. Upon infection, plants mount a complex immune response to restrict virus replication and spread, involving a multilayered defense system that includes defense hormones, RNA silencing, and immune receptors. To counter these defenses, tobamoviruses have evolved various strategies to evade or suppress the different immune pathways. Understanding the interactions between tobamoviruses and the plant immune pathways is crucial for the development of effective control measures and genetic resistance to these viruses. In this review, we discuss past and current knowledge of the intricate relationship between tobamoviruses and host immunity. We use this knowledge to understand the emergence of ToBRFV and discuss potential approaches for the development of new resistance strategies to cope with emerging tobamoviruses.
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Affiliation(s)
- Ziv Spiegelman
- Department of Plant Pathology and Weed Research, Agricultural Research Organization-The Volcani Institute, Rishon LeZion, Israel;
| | - Savithramma P Dinesh-Kumar
- Department of Plant Biology and Genome Center, College of Biological Sciences, University of California, Davis, California, USA
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22
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Atsumi G, Naramoto S, Nishihara M, Nakatsuka T, Tomita R, Matsushita Y, Hoshi N, Shirakawa A, Kobayashi K, Fukuda H, Sekine KT. Identification of a novel viral factor inducing tumorous symptoms by disturbing vascular development in planta. J Virol 2023; 97:e0046323. [PMID: 37668368 PMCID: PMC10537666 DOI: 10.1128/jvi.00463-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 06/14/2023] [Indexed: 09/06/2023] Open
Abstract
Plant viruses induce various disease symptoms that substantially impact agriculture, but the underlying mechanisms of viral disease in plants are poorly understood. Kobu-sho is a disease in gentian that shows gall formation with ectopic development of lignified cells and vascular tissues such as xylem. Here, we show that a gene fragment of gentian Kobu-sho-associated virus, which is designated as Kobu-sho-inducing factor (KOBU), induces gall formation accompanied by ectopic development of lignified cells and xylem-like tissue in Nicotiana benthamiana. Transgenic gentian expressing KOBU exhibited tumorous symptoms, confirming the gall-forming activity of KOBU. Surprisingly, KOBU expression can also induce differentiation of an additional leaf-like tissue on the abaxial side of veins in normal N. benthamiana and gentian leaves. Transcriptome analysis with Arabidopsis thaliana expressing KOBU revealed that KOBU activates signaling pathways that regulate xylem development. KOBU protein forms granules and plate-like structures and co-localizes with mRNA splicing factors within the nucleus. Our findings suggest that KOBU is a novel pleiotropic virulence factor that stimulates vascular and leaf development. IMPORTANCE While various mechanisms determine disease symptoms in plants depending on virus-host combinations, the details of how plant viruses induce symptoms remain largely unknown in most plant species. Kobu-sho is a disease in gentian that shows gall formation with ectopic development of lignified cells and vascular tissues such as xylem. Our findings demonstrate that a gene fragment of gentian Kobu-sho-associated virus (GKaV), which is designated as Kobu-sho-inducing factor, induces the gall formation accompanied by the ectopic development of lignified cells and xylem-like tissue in Nicotiana benthamiana. The molecular mechanism by which gentian Kobu-sho-associated virus induces the Kobu-sho symptoms will provide new insight into not only plant-virus interactions but also the regulatory mechanisms underlying vascular and leaf development.
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Affiliation(s)
- Go Atsumi
- Iwate Biotechnology Research Center, Kitakami, Iwate, Japan
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology, Sapporo, Hokkaido, Japan
- Graduate School of Agriculture, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Satoshi Naramoto
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | | | | | - Reiko Tomita
- Iwate Biotechnology Research Center, Kitakami, Iwate, Japan
| | - Yosuke Matsushita
- National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Nobue Hoshi
- Iwate Agricultural Research Center, Kitakami, Iwate, Japan
| | | | - Kappei Kobayashi
- Iwate Biotechnology Research Center, Kitakami, Iwate, Japan
- Faculty of Agriculture, Ehime University, Matsuyama, Ehime, Japan
| | - Hiroo Fukuda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Ken-Taro Sekine
- Iwate Biotechnology Research Center, Kitakami, Iwate, Japan
- Faculty of Agriculture, University of the Ryukyus, Nishihara, Okinawa, Japan
- Department of Environmental Sciences and Conservation Biology, The United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima, Kagoshima, Japan
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23
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Huang C, Sede AR, Elvira-González L, Yan Y, Rodriguez ME, Mutterer J, Boutant E, Shan L, Heinlein M. dsRNA-induced immunity targets plasmodesmata and is suppressed by viral movement proteins. THE PLANT CELL 2023; 35:3845-3869. [PMID: 37378592 PMCID: PMC10533371 DOI: 10.1093/plcell/koad176] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 05/24/2023] [Accepted: 05/23/2023] [Indexed: 06/29/2023]
Abstract
Emerging evidence indicates that in addition to its well-recognized functions in antiviral RNA silencing, dsRNA elicits pattern-triggered immunity (PTI), likely contributing to plant resistance against virus infections. However, compared to bacterial and fungal elicitor-mediated PTI, the mode-of-action and signaling pathway of dsRNA-induced defense remain poorly characterized. Here, using multicolor in vivo imaging, analysis of GFP mobility, callose staining, and plasmodesmal marker lines in Arabidopsis thaliana and Nicotiana benthamiana, we show that dsRNA-induced PTI restricts the progression of virus infection by triggering callose deposition at plasmodesmata, thereby likely limiting the macromolecular transport through these cell-to-cell communication channels. The plasma membrane-resident SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE 1, the BOTRYTIS INDUCED KINASE1/AVRPPHB SUSCEPTIBLE1-LIKE KINASE1 kinase module, PLASMODESMATA-LOCATED PROTEINs 1/2/3, as well as CALMODULIN-LIKE 41 and Ca2+ signals are involved in the dsRNA-induced signaling leading to callose deposition at plasmodesmata and antiviral defense. Unlike the classical bacterial elicitor flagellin, dsRNA does not trigger a detectable reactive oxygen species (ROS) burst, substantiating the idea that different microbial patterns trigger partially shared immune signaling frameworks with distinct features. Likely as a counter strategy, viral movement proteins from different viruses suppress the dsRNA-induced host response leading to callose deposition to achieve infection. Thus, our data support a model in which plant immune signaling constrains virus movement by inducing callose deposition at plasmodesmata and reveals how viruses counteract this layer of immunity.
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Affiliation(s)
- Caiping Huang
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 67000 Strasbourg, France
| | - Ana Rocío Sede
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 67000 Strasbourg, France
| | - Laura Elvira-González
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 67000 Strasbourg, France
| | - Yan Yan
- Department of Biochemistry and Biophysics, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Miguel Eduardo Rodriguez
- Department of Biochemistry and Biophysics, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Jérôme Mutterer
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 67000 Strasbourg, France
| | - Emmanuel Boutant
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 67000 Strasbourg, France
| | - Libo Shan
- Department of Biochemistry and Biophysics, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Manfred Heinlein
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 67000 Strasbourg, France
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Liu S, Su C, Zhang D, Song Z, Wang X, Wang J, Yuan X. Construction of a Delivery Platform for Vaccine Based on Modified Nanotubes: Sustainable Prevention against Plant Viral Disease, Simplified Preparation Method, and Protection of Plasmid. ACS APPLIED MATERIALS & INTERFACES 2023; 15:44541-44553. [PMID: 37672476 DOI: 10.1021/acsami.3c09168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Control of plant viral diseases through cross-protection conferred by an attenuated vaccine is an important strategy for plant protection. However, the mutated site of an attenuated vaccine may not be stably inherited, while viruses have evolved efficient repair mechanisms for the maintenance of genomic integrity. Here, the wide host range and broad selection of mutation sites in cucumber mosaic virus (CMV) enabled construction of an attenuated vaccine through insertional mutation of the CMV 2b protein. CMV-R2E was stably inherited in tobacco for more than 10 generations and had a high relative control efficacy of CMV. Then, the use of polyetherimide (PEI)-modified functionalized carboxylated single-walled carbon nanotubes (PSWNTs) was investigated for vaccine delivery to address the problems of poor stability, complex procedure on field application, and exacting storage conditions with Agrobacterium inoculation. After co-incubating at a 1:300 ratio for 30 min, the vaccine and PSWNTs combined to form pCMV-R2E@PSWNTs, which resulted in a significant increase in the average height of the nanoparticles from 6.56 to 72.34 nm. The relative control efficacy of pCMV-R2E@PSWNTs to CMV was found to be 90.37%. Furthermore, the protective effect of PSWNTs on plasmids was investigated under various environmental conditions and the potential plant toxicity of pCMV-R2E@PSWNTs was assessed, providing a theoretical basis for field application of the vaccine nano-delivery system. A highly effective, stable viral vaccine for plants was thus developed and combined with nanocarriers to address the problems of field application. This approach has the potential to enable wider use of attenuated vaccines for sustainable prevention against plant viral disease in the field.
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Affiliation(s)
- Shanshan Liu
- Pest Integrated Management Key Laboratory of China Tobacco, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266100, P. R. China
| | - Chenyu Su
- Pest Integrated Management Key Laboratory of China Tobacco, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266100, P. R. China
| | - Deping Zhang
- China Tobacco Guangxi Industrial Co., Ltd., Nanning 530000, P. R. China
| | - Zhanfeng Song
- China Tobacco Guangxi Industrial Co., Ltd., Nanning 530000, P. R. China
| | - Xinwei Wang
- Pest Integrated Management Key Laboratory of China Tobacco, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266100, P. R. China
| | - Jie Wang
- Pest Integrated Management Key Laboratory of China Tobacco, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266100, P. R. China
| | - Xuefeng Yuan
- Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai'an 271000, P. R. China
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25
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Martínez‐Pérez M, Aparicio F, Arribas‐Hernández L, Tankmar MD, Rennie S, von Bülow S, Lindorff‐Larsen K, Brodersen P, Pallas V. Plant YTHDF proteins are direct effectors of antiviral immunity against an N6-methyladenosine-containing RNA virus. EMBO J 2023; 42:e113378. [PMID: 37431920 PMCID: PMC10505913 DOI: 10.15252/embj.2022113378] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 05/31/2023] [Accepted: 06/15/2023] [Indexed: 07/12/2023] Open
Abstract
In virus-host interactions, nucleic acid-directed first lines of defense that allow viral clearance without compromising growth are of paramount importance. Plants use the RNA interference pathway as a basal antiviral immune system, but additional RNA-based mechanisms of defense also exist. The infectivity of a plant positive-strand RNA virus, alfalfa mosaic virus (AMV), relies on the demethylation of viral RNA by the recruitment of the cellular N6-methyladenosine (m6 A) demethylase ALKBH9B, but how demethylation of viral RNA promotes AMV infection remains unknown. Here, we show that inactivation of the Arabidopsis cytoplasmic YT521-B homology domain (YTH)-containing m6 A-binding proteins ECT2, ECT3, and ECT5 is sufficient to restore AMV infectivity in partially resistant alkbh9b mutants. We further show that the antiviral function of ECT2 is distinct from its previously demonstrated function in the promotion of primordial cell proliferation: an ect2 mutant carrying a small deletion in its intrinsically disordered region is partially compromised for antiviral defense but not for developmental functions. These results indicate that the m6 A-YTHDF axis constitutes a novel branch of basal antiviral immunity in plants.
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Affiliation(s)
- Mireya Martínez‐Pérez
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones CientíficasUniversitat Politècnica de ValènciaValenciaSpain
| | - Frederic Aparicio
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones CientíficasUniversitat Politècnica de ValènciaValenciaSpain
| | | | | | - Sarah Rennie
- Department of BiologyUniversity of CopenhagenCopenhagenDenmark
| | - Sören von Bülow
- Department of BiologyUniversity of CopenhagenCopenhagenDenmark
| | | | - Peter Brodersen
- Department of BiologyUniversity of CopenhagenCopenhagenDenmark
| | - Vicente Pallas
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones CientíficasUniversitat Politècnica de ValènciaValenciaSpain
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26
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Mäkinen K, Aspelin W, Pollari M, Wang L. How do they do it? The infection biology of potyviruses. Adv Virus Res 2023; 117:1-79. [PMID: 37832990 DOI: 10.1016/bs.aivir.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2023]
Affiliation(s)
- Kristiina Mäkinen
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland.
| | - William Aspelin
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Maija Pollari
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Linping Wang
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
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27
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Tu CW, Huang YW, Lee CW, Kuo SY, Lin NS, Hsu YH, Hu CC. Argonaute 5-mediated antiviral defense and viral counter-defense in Nicotiana benthamiana. Virus Res 2023; 334:199179. [PMID: 37481165 PMCID: PMC10405324 DOI: 10.1016/j.virusres.2023.199179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 07/18/2023] [Accepted: 07/19/2023] [Indexed: 07/24/2023]
Abstract
The argonaute (AGO) family proteins play a crucial role in preventing viral invasions through the plant antiviral RNA silencing pathway, with distinct AGO proteins recruited for specific antiviral mechanisms. Our previous study revealed that Nicotiana benthamiana AGO5 (NbAGO5) expression was significantly upregulated in response to bamboo mosaic virus (BaMV) infection. However, the roles of NbAGO5 in antiviral mechanisms remained to be explored. In this research, we examined the antiviral functions of NbAGO5 in the infections of different viruses. It was found that the accumulation of NbAGO5 was induced not only at the RNA but also at the protein level following the infections of BaMV, potato virus X (PVX), tobacco mosaic virus (TMV), and cucumber mosaic virus (CMV) in N. benthamiana. To explore the antiviral mechanism and regulatory function of NbAGO5, we generated NbAGO5 overexpression (OE-NbAGO5) and knockout (nbago5) transgenic N. benthamiana lines. Our findings reveal that NbAGO5 provides defense against BaMV, PVX, TMV, and a mutant CMV deficient in 2b gene, but not against the wild-type CMV and turnip mosaic virus (TuMV). Through affinity purification and small RNA northern blotting, we demonstrated that NbAGO5 exerts its antiviral function by binding to viral small interfering RNAs (vsiRNAs). Moreover, we observed that CMV 2b and TuMV HC-Pro interact with NbAGO5, triggering its degradation via the 26S proteasome and autophagy pathways, thereby allowing these viruses to overcome NbAGO5-mediated defense. In addition, TuMV HC-Pro provides another line of counter-defense by interfering with vsiRNA binding by NbAGO5. Our study provides further insights into the antiviral RNA interference mechanism and the complex interplay between NbAGO5 and plant viruses.
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Affiliation(s)
- Chin-Wei Tu
- PhD Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung 40227, Taiwan
| | - Ying-Wen Huang
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan; Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan
| | - Chin-Wei Lee
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan
| | - Song-Yi Kuo
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604, Singapore
| | - Na-Sheng Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Yau-Heiu Hsu
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan; Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan
| | - Chung-Chi Hu
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan; Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan.
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28
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Choi J, Pakbaz S, Yepes LM, Cieniewicz EJ, Schmitt-Keichinger C, Labarile R, Minutillo SA, Heck M, Hua J, Fuchs M. Grapevine Fanleaf Virus RNA1-Encoded Proteins 1A and 1B Hel Suppress RNA Silencing. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2023; 36:558-571. [PMID: 36998121 DOI: 10.1094/mpmi-01-23-0008-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Grapevine fanleaf virus (GFLV) (genus Nepovirus, family Secoviridae) causes fanleaf degeneration, one of the most damaging viral diseases of grapevines. Despite substantial advances at deciphering GFLV-host interactions, how this virus overcomes the host antiviral pathways of RNA silencing is poorly understood. In this study, we identified viral suppressors of RNA silencing (VSRs) encoded by GFLV, using fluorescence assays, and tested their capacity at modifying host gene expression in transgenic Nicotiana benthamiana expressing the enhanced green fluorescent protein gene (EGFP). Results revealed that GFLV RNA1-encoded protein 1A, for which a function had yet to be assigned, and protein 1BHel, a putative helicase, reverse systemic RNA silencing either individually or as a fused form (1ABHel) predicted as an intermediary product of RNA1 polyprotein proteolytic processing. The GFLV VSRs differentially altered the expression of plant host genes involved in RNA silencing, as shown by reverse transcription-quantitative PCR. In a co-infiltration assay with an EGFP hairpin construct, protein 1A upregulated NbDCL2, NbDCL4, and NbRDR6, and proteins 1BHel and 1A+1BHel upregulated NbDCL2, NbDCL4, NbAGO1, NbAGO2, and NbRDR6, while protein 1ABHel upregulated NbAGO1 and NbRDR6. In a reversal of systemic silencing assay, protein 1A upregulated NbDCL2 and NbAGO2 and protein 1ABHel upregulated NbDCL2, NbDCL4, and NbAGO1. This is the first report of VSRs encoded by a nepovirus RNA1 and of two VSRs that act either individually or as a predicted fused form to counteract the systemic antiviral host defense, suggesting that GFLV might devise a unique counterdefense strategy to interfere with various steps of the plant antiviral RNA silencing pathways during infection. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Jiyeong Choi
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Cornell AgriTech, Geneva, NY 14456, U.S.A
| | - Samira Pakbaz
- Plant Pathology Department, Faculty of Agriculture and Natural Resources, Lorestan University, Khorramabad, Iran
| | - Luz Marcela Yepes
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Cornell AgriTech, Geneva, NY 14456, U.S.A
| | - Elizabeth Jeannette Cieniewicz
- Deparment of Plant and Environmental Sciences, College of Agriculture, Forestry, and Life Sciences, Clemson University, Clemson, SC 29634, U.S.A
| | - Corinne Schmitt-Keichinger
- CNRS, IBMP UPR 2357, Université de Strasbourg, 67000 Strasbourg, France
- INRAE, SVQV UMR 1131, Université de Strasbourg, 68000 Colmar, France
| | - Rossella Labarile
- National Research Council (CNR), Institute of Chemical-Physical Processes, Via Amendola 165/A, 70126 Bari, Italy
| | - Serena Anna Minutillo
- International Center for Advanced Mediterranean Agronomic Studies - Institute of Bari (CIHEAM-Bari), 70010 Valenzano, Italy
| | - Michelle Heck
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, U.S.A
- Emerging Pests and Pathogens Research Unit, USDA Agricultural Research Service, Robert W. Holley Center for Agriculture and Health, Ithaca, NY 14853, U.S.A
| | - Jian Hua
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, U.S.A
| | - Marc Fuchs
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Cornell AgriTech, Geneva, NY 14456, U.S.A
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29
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Taliansky ME, Love AJ, Kołowerzo-Lubnau A, Smoliński DJ. Cajal bodies: Evolutionarily conserved nuclear biomolecular condensates with properties unique to plants. THE PLANT CELL 2023; 35:3214-3235. [PMID: 37202374 PMCID: PMC10473218 DOI: 10.1093/plcell/koad140] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 04/24/2023] [Accepted: 04/27/2023] [Indexed: 05/20/2023]
Abstract
Proper orchestration of the thousands of biochemical processes that are essential to the life of every cell requires highly organized cellular compartmentalization of dedicated microenvironments. There are 2 ways to create this intracellular segregation to optimize cellular function. One way is to create specific organelles, enclosed spaces bounded by lipid membranes that regulate macromolecular flux in and out of the compartment. A second way is via membraneless biomolecular condensates that form due to to liquid-liquid phase separation. Although research on these membraneless condensates has historically been performed using animal and fungal systems, recent studies have explored basic principles governing the assembly, properties, and functions of membraneless compartments in plants. In this review, we discuss how phase separation is involved in a variety of key processes occurring in Cajal bodies (CBs), a type of biomolecular condensate found in nuclei. These processes include RNA metabolism, formation of ribonucleoproteins involved in transcription, RNA splicing, ribosome biogenesis, and telomere maintenance. Besides these primary roles of CBs, we discuss unique plant-specific functions of CBs in RNA-based regulatory pathways such as nonsense-mediated mRNA decay, mRNA retention, and RNA silencing. Finally, we summarize recent progress and discuss the functions of CBs in responses to pathogen attacks and abiotic stresses, responses that may be regulated via mechanisms governed by polyADP-ribosylation. Thus, plant CBs are emerging as highly complex and multifunctional biomolecular condensates that are involved in a surprisingly diverse range of molecular mechanisms that we are just beginning to appreciate.
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Affiliation(s)
| | - Andrew J Love
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - Agnieszka Kołowerzo-Lubnau
- Department of Cellular and Molecular Biology, Nicolaus Copernicus University, Lwowska 1, 87-100 Torun, Poland
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wilenska 4, 87-100 Torun, Poland
| | - Dariusz Jan Smoliński
- Department of Cellular and Molecular Biology, Nicolaus Copernicus University, Lwowska 1, 87-100 Torun, Poland
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wilenska 4, 87-100 Torun, Poland
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30
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Jovanović I, Frantová N, Zouhar J. A sword or a buffet: plant endomembrane system in viral infections. FRONTIERS IN PLANT SCIENCE 2023; 14:1226498. [PMID: 37636115 PMCID: PMC10453817 DOI: 10.3389/fpls.2023.1226498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 07/25/2023] [Indexed: 08/29/2023]
Abstract
The plant endomembrane system is an elaborate collection of membrane-bound compartments that perform distinct tasks in plant growth and development, and in responses to abiotic and biotic stresses. Most plant viruses are positive-strand RNA viruses that remodel the host endomembrane system to establish intricate replication compartments. Their fundamental role is to create optimal conditions for viral replication, and to protect replication complexes and the cell-to-cell movement machinery from host defenses. In addition to the intracellular antiviral defense, represented mainly by RNA interference and effector-triggered immunity, recent findings indicate that plant antiviral immunity also includes membrane-localized receptor-like kinases that detect viral molecular patterns and trigger immune responses, which are similar to those observed for bacterial and fungal pathogens. Another recently identified part of plant antiviral defenses is executed by selective autophagy that mediates a specific degradation of viral proteins, resulting in an infection arrest. In a perpetual tug-of-war, certain host autophagy components may be exploited by viral proteins to support or protect an effective viral replication. In this review, we present recent advances in the understanding of the molecular interplay between viral components and plant endomembrane-associated pathways.
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Affiliation(s)
- Ivana Jovanović
- Department of Crop Science, Breeding and Plant Medicine, Faculty of AgriSciences, Mendel University in Brno, Brno, Czechia
| | - Nicole Frantová
- Department of Crop Science, Breeding and Plant Medicine, Faculty of AgriSciences, Mendel University in Brno, Brno, Czechia
| | - Jan Zouhar
- Central European Institute of Technology, Faculty of AgriSciences, Mendel University in Brno, Brno, Czechia
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31
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Silva-Martins G, Roussin-Léveillée C, Bolaji A, Veerapen VP, Moffett P. A Jasmonic Acid-Related Mechanism Affects ARGONAUTE5 Expression and Antiviral Defense Against Potato Virus X in Arabidopsis thaliana. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2023; 36:425-433. [PMID: 36853196 DOI: 10.1094/mpmi-11-22-0224-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
During virus infection, Argonaute (AGO) proteins bind to Dicer-produced virus small interfering RNAs and target viral RNA based on sequence complementarity, thereby limiting virus proliferation. The Arabidopsis AGO2 protein is important for resistance to multiple viruses, including potato virus X (PVX). In addition, AGO5 is important in systemic defense against PVX. Normally AGO5 is expressed only in reproductive tissues, and its induction by virus infection is thought to be important for its participation in antiviral defense. However, it is unclear what mechanisms induce AGO5 expression in response to virus infection. Here, we show that dde2-2, a mutant compromised in jasmonic acid (JA) biosynthesis, displays constitutive upregulation of AGO5. This mutant also showed increased resistance to PVX and this resistance was dependent on a functional AGO5 gene. Furthermore, methyl jasmonate treatment ablated AGO5 expression in leaves during virus infection and resulted in increased susceptibility to virus. Our results further support a role for AGO5 in antiviral RNA silencing and a negative regulation by JA, a plant hormone associated with defense against plant-feeding arthropods, which are often the vectors of plant viruses. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Guilherme Silva-Martins
- Centre SÈVE, Département de Biologie, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | | | - Ayooluwa Bolaji
- Centre SÈVE, Département de Biologie, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | - Varusha Pillay Veerapen
- Centre SÈVE, Département de Biologie, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | - Peter Moffett
- Centre SÈVE, Département de Biologie, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
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32
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Liu S, Han Y, Li WX, Ding SW. Infection Defects of RNA and DNA Viruses Induced by Antiviral RNA Interference. Microbiol Mol Biol Rev 2023; 87:e0003522. [PMID: 37052496 PMCID: PMC10304667 DOI: 10.1128/mmbr.00035-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023] Open
Abstract
Immune recognition of viral genome-derived double-stranded RNA (dsRNA) molecules and their subsequent processing into small interfering RNAs (siRNAs) in plants, invertebrates, and mammals trigger specific antiviral immunity known as antiviral RNA interference (RNAi). Immune sensing of viral dsRNA is sequence-independent, and most regions of viral RNAs are targeted by virus-derived siRNAs which extensively overlap in sequence. Thus, the high mutation rates of viruses do not drive immune escape from antiviral RNAi, in contrast to other mechanisms involving specific virus recognition by host immune proteins such as antibodies and resistance (R) proteins in mammals and plants, respectively. Instead, viruses actively suppress antiviral RNAi at various key steps with a group of proteins known as viral suppressors of RNAi (VSRs). Some VSRs are so effective in virus counter-defense that potent inhibition of virus infection by antiviral RNAi is undetectable unless the cognate VSR is rendered nonexpressing or nonfunctional. Since viral proteins are often multifunctional, resistance phenotypes of antiviral RNAi are accurately defined by those infection defects of VSR-deletion mutant viruses that are efficiently rescued by host deficiency in antiviral RNAi. Here, we review and discuss in vivo infection defects of VSR-deficient RNA and DNA viruses resulting from the actions of host antiviral RNAi in model systems.
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Affiliation(s)
- Si Liu
- Department of Microbiology & Plant Pathology, University of California, Riverside, California, USA
- Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, California, USA
| | - Yanhong Han
- Vector-borne Virus Research Center, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Wan-Xiang Li
- Department of Microbiology & Plant Pathology, University of California, Riverside, California, USA
- Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, California, USA
| | - Shou-Wei Ding
- Department of Microbiology & Plant Pathology, University of California, Riverside, California, USA
- Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, California, USA
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33
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Zwolinski AM, Brigden A, Rey MEC. Differences in the 3' intergenic region and the V2 protein of two sequence variants of tomato curly stunt virus play an important role in disease pathology in Nicotiana benthamiana. PLoS One 2023; 18:e0286149. [PMID: 37220127 DOI: 10.1371/journal.pone.0286149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 05/10/2023] [Indexed: 05/25/2023] Open
Abstract
Tomato production in South Africa is threatened by the emergence of tomato curly stunt virus (ToCSV), a monopartite Begomovirus transmitted by the whitefly vector Bemisia tabaci (Genn.). We investigated the role of sequence differences present in the 3' intergenic region (IR) and the V2 coding region on the differing infectivity of ToCSV sequence variant isolates V30 and V22 in the model host Nicotiana benthamiana. Using virus mutant chimeras, we determined that the development of the upward leaf roll symptom phenotype is mediated by sequence differences present in the 3' IR containing the TATA-associated composite element. Sequence differences present in the V2 coding region are responsible for modulating disease severity and symptom recovery in V22-infected plants. Serine substitution of V22 V2 Val27 resulted in a significant increase in disease severity with reduced recovery, the first study to demonstrate the importance of this V2 residue in disease development. Two putative ORFs, C5 and C6, were identified using in silico analysis and detection of an RNA transcript spanning their coding region suggests that these ORFs may be transcribed during infection. Additional virus-derived RNA transcripts spanning multiple ORFs and crossing the boundaries of recognised polycistronic transcripts, as well as the origin of replication within the IR, were detected in ToCSV-infected plants providing evidence of bidirectional readthrough transcription. From our results, we conclude that the diverse responses of the model host to ToCSV infection is influenced by select sequence differences and our findings provide several avenues for further investigation into the mechanisms behind these responses to infection.
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Affiliation(s)
- Alexander M Zwolinski
- School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, South Africa
| | - Alison Brigden
- School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, South Africa
| | - Marie E C Rey
- School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, South Africa
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Atabekova AK, Solovieva AD, Chergintsev DA, Solovyev AG, Morozov SY. Role of Plant Virus Movement Proteins in Suppression of Host RNAi Defense. Int J Mol Sci 2023; 24:ijms24109049. [PMID: 37240394 DOI: 10.3390/ijms24109049] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 05/18/2023] [Accepted: 05/19/2023] [Indexed: 05/28/2023] Open
Abstract
One of the systems of plant defense against viral infection is RNA silencing, or RNA interference (RNAi), in which small RNAs derived from viral genomic RNAs and/or mRNAs serve as guides to target an Argonaute nuclease (AGO) to virus-specific RNAs. Complementary base pairing between the small interfering RNA incorporated into the AGO-based protein complex and viral RNA results in the target cleavage or translational repression. As a counter-defensive strategy, viruses have evolved to acquire viral silencing suppressors (VSRs) to inhibit the host plant RNAi pathway. Plant virus VSR proteins use multiple mechanisms to inhibit silencing. VSRs are often multifunctional proteins that perform additional functions in the virus infection cycle, particularly, cell-to-cell movement, genome encapsidation, or replication. This paper summarizes the available data on the proteins with dual VSR/movement protein activity used by plant viruses of nine orders to override the protective silencing response and reviews the different molecular mechanisms employed by these proteins to suppress RNAi.
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Affiliation(s)
- Anastasia K Atabekova
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia
| | - Anna D Solovieva
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia
| | - Denis A Chergintsev
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia
| | - Andrey G Solovyev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia
| | - Sergey Y Morozov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia
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Nigam D, Muthukrishnan E, Flores-López LF, Nigam M, Wamaitha MJ. Comparative Genome Analysis of Old World and New World TYLCV Reveals a Biasness toward Highly Variable Amino Acids in Coat Protein. PLANTS (BASEL, SWITZERLAND) 2023; 12:1995. [PMID: 37653912 PMCID: PMC10223811 DOI: 10.3390/plants12101995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/01/2023] [Accepted: 05/08/2023] [Indexed: 09/02/2023]
Abstract
Begomoviruses, belonging to the family Geminiviridae and the genus Begomovirus, are DNA viruses that are transmitted by whitefly Bemisia tabaci (Gennadius) in a circulative persistent manner. They can easily adapt to new hosts and environments due to their wide host range and global distribution. However, the factors responsible for their adaptability and coevolutionary forces are yet to be explored. Among BGVs, TYLCV exhibits the broadest range of hosts. In this study, we have identified variable and coevolving amino acid sites in the proteins of Tomato yellow leaf curl virus (TYLCV) isolates from Old World (African, Indian, Japanese, and Oceania) and New World (Central and Southern America). We focused on mutations in the coat protein (CP), as it is highly variable and interacts with both vectors and host plants. Our observations indicate that some mutations were accumulating in Old World TYLCV isolates due to positive selection, with the S149N mutation being of particular interest. This mutation is associated with TYLCV isolates that have spread in Europe and Asia and is dominant in 78% of TYLCV isolates. On the other hand, the S149T mutation is restricted to isolates from Saudi Arabia. We further explored the implications of these amino acid changes through structural modeling. The results presented in this study suggest that certain hypervariable regions in the genome of TYLCV are conserved and may be important for adapting to different host environments. These regions could contribute to the mutational robustness of the virus, allowing it to persist in different host populations.
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Affiliation(s)
- Deepti Nigam
- Institute for Genomics of Crop Abiotic Stress Tolerance, Department of Plant and Soil Science, Texas Tech University (TTU), Lubbock, TX 79409, USA
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14850, USA
| | | | - Luis Fernando Flores-López
- Departamento de Biotecnología y Bioquímica, Centro de Investigacióny de Estudios Avanzados de IPN (CINVESTAV) Unidad Irapuato, Irapuato 368224, Mexico
| | - Manisha Nigam
- Department of Biochemistry, Hemvati Nandan Bahuguna Garhwal University, Srinagar 246174, Uttarakhand, India
| | - Mwathi Jane Wamaitha
- Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi P.O. Box 14733-00800, Kenya
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36
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Uhl S, Jang C, Frere JJ, Jordan TX, Simon AE, tenOever BR. ADAR1 Biology Can Hinder Effective Antiviral RNA Interference. J Virol 2023; 97:e0024523. [PMID: 37017521 PMCID: PMC10134826 DOI: 10.1128/jvi.00245-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 03/10/2023] [Indexed: 04/06/2023] Open
Abstract
Viruses constantly evolve and adapt to the antiviral defenses of their hosts. The biology of viral circumvention of these selective pressures can often be attributed to the acquisition of novel antagonistic gene products or by rapid genome change that prevents host recognition. To study viral evasion of RNA interference (RNAi)-based defenses, we established a robust antiviral system in mammalian cells using recombinant Sendai virus designed to be targeted by endogenous host microRNAs (miRNAs) with perfect complementarity. Using this system, we previously demonstrated the intrinsic ability of positive-strand RNA viruses to escape this selective pressure via homologous recombination, which was not observed in negative-strand RNA viruses. Here, we show that given extensive time, escape of miRNA-targeted Sendai virus was enabled by host adenosine deaminase acting on RNA 1 (ADAR1). Independent of the viral transcript targeted, ADAR1 editing resulted in disruption of the miRNA-silencing motif, suggesting an intolerance for extensive RNA-RNA interactions necessary for antiviral RNAi. This was further supported in Nicotiana benthamiana, where exogenous expression of ADAR1 interfered with endogenous RNAi. Together, these results suggest that ADAR1 diminishes the effectiveness of RNAi and may explain why it is absent in species that utilize this antiviral defense system. IMPORTANCE All life at the cellular level has the capacity to induce an antiviral response. Here, we examine the result of imposing the antiviral response of one branch of life onto another and find evidence for conflict. To determine the consequences of eliciting an RNAi-like defense in mammals, we applied this pressure to a recombinant Sendai virus in cell culture. We find that ADAR1, a host gene involved in regulation of the mammalian response to virus, prevented RNAi-mediated silencing and subsequently allowed for viral replication. In addition, the expression of ADAR1 in Nicotiana benthamiana, which lacks ADARs and has an endogenous RNAi system, suppresses gene silencing. These data indicate that ADAR1 is disruptive to RNAi biology and provide insight into the evolutionary relationship between ADARs and antiviral defenses in eukaryotic life.
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Affiliation(s)
- Skyler Uhl
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Microbiology | Medicine, New York University, New York, New York, USA
| | - Chanyong Jang
- Department of Cell Biology and Molecular Genetics, University of Maryland College Park, College Park, Maryland, USA
| | - Justin J. Frere
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Microbiology | Medicine, New York University, New York, New York, USA
| | - Tristan X. Jordan
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Anne E. Simon
- Department of Cell Biology and Molecular Genetics, University of Maryland College Park, College Park, Maryland, USA
| | - Benjamin R. tenOever
- Department of Microbiology | Medicine, New York University, New York, New York, USA
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37
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Noris E, Pegoraro M, Palzhoff S, Urrejola C, Wochner N, Kober S, Ruoff K, Matić S, Schnepf V, Weisshaar N, Wege C. Differential Effects of RNA-Dependent RNA Polymerase 6 (RDR6) Silencing on New and Old World Begomoviruses in Nicotiana benthamiana. Viruses 2023; 15:v15040919. [PMID: 37112899 PMCID: PMC10143181 DOI: 10.3390/v15040919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/28/2023] [Accepted: 03/30/2023] [Indexed: 04/29/2023] Open
Abstract
RNA-dependent RNA polymerases (RDRs) are key players in the antiviral defence mediated by RNA silencing in plants. RDR6 is one of the major components of the process, regulating the infection of certain RNA viruses. To better clarify its function against DNA viruses, we analyzed the effect of RDR6 inactivation (RDR6i) in N. benthamiana plants on two phloem-limited begomoviruses, the bipartite Abutilon mosaic virus (AbMV) and the monopartite tomato yellow leaf curl Sardinia virus (TYLCSV). We observed exacerbated symptoms and DNA accumulation for the New World virus AbMV in RDR6i plants, varying with the plant growth temperature (ranging from 16 °C to 33 °C). However, for the TYLCSV of Old World origin, RDR6 depletion only affected symptom expression at elevated temperatures and to a minor extent; it did not affect the viral titre. The accumulation of viral siRNA differed between the two begomoviruses, being increased in RDR6i plants infected by AbMV but decreased in those infected by TYLCSV compared to wild-type plants. In situ hybridization revealed a 6.5-fold increase in the number of AbMV-infected nuclei in RDR6i plants but without egress from the phloem tissues. These results support the concept that begomoviruses adopt different strategies to counteract plant defences and that TYLCSV evades the functions exerted by RDR6 in this host.
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Affiliation(s)
- Emanuela Noris
- Institute for Sustainable Plant Protection, National Research Council of Italy, Strada delle Cacce 73, 10135 Torino, Italy
| | - Mattia Pegoraro
- Institute for Sustainable Plant Protection, National Research Council of Italy, Strada delle Cacce 73, 10135 Torino, Italy
| | - Sandra Palzhoff
- Institute of Biomaterials and Biomolecular Systems, Molecular and Synthetic Plant Virology, University of Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany
| | - Catalina Urrejola
- Institute of Biomaterials and Biomolecular Systems, Molecular and Synthetic Plant Virology, University of Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany
| | - Nicolai Wochner
- Institute of Biomaterials and Biomolecular Systems, Molecular and Synthetic Plant Virology, University of Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany
| | - Sigi Kober
- Institute of Biomaterials and Biomolecular Systems, Molecular and Synthetic Plant Virology, University of Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany
| | - Kerstin Ruoff
- Institute of Biomaterials and Biomolecular Systems, Molecular and Synthetic Plant Virology, University of Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany
| | - Slavica Matić
- Institute for Sustainable Plant Protection, National Research Council of Italy, Strada delle Cacce 73, 10135 Torino, Italy
| | - Vera Schnepf
- Institute of Biomaterials and Biomolecular Systems, Molecular and Synthetic Plant Virology, University of Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany
| | - Nina Weisshaar
- Institute of Biomaterials and Biomolecular Systems, Molecular and Synthetic Plant Virology, University of Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany
| | - Christina Wege
- Institute of Biomaterials and Biomolecular Systems, Molecular and Synthetic Plant Virology, University of Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany
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Rosas-Diaz T, Cana-Quijada P, Wu M, Hui D, Fernandez-Barbero G, Macho AP, Solano R, Castillo AG, Wang XW, Lozano-Duran R, Bejarano ER. The transcriptional regulator JAZ8 interacts with the C2 protein from geminiviruses and limits the geminiviral infection in Arabidopsis. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2023. [PMID: 36946519 DOI: 10.1111/jipb.13482] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 03/17/2023] [Indexed: 05/06/2023]
Abstract
Jasmonates (JAs) are phytohormones that finely regulate critical biological processes, including plant development and defense. JASMONATE ZIM-DOMAIN (JAZ) proteins are crucial transcriptional regulators that keep JA-responsive genes in a repressed state. In the presence of JA-Ile, JAZ repressors are ubiquitinated and targeted for degradation by the ubiquitin/proteasome system, allowing the activation of downstream transcription factors and, consequently, the induction of JA-responsive genes. A growing body of evidence has shown that JA signaling is crucial in defending against plant viruses and their insect vectors. Here, we describe the interaction of C2 proteins from two tomato-infecting geminiviruses from the genus Begomovirus, tomato yellow leaf curl virus (TYLCV) and tomato yellow curl Sardinia virus (TYLCSaV), with the transcriptional repressor JAZ8 from Arabidopsis thaliana and its closest orthologue in tomato, SlJAZ9. Both JAZ and C2 proteins colocalize in the nucleus, forming discrete nuclear speckles. Overexpression of JAZ8 did not lead to altered responses to TYLCV infection in Arabidopsis; however, knock-down of JAZ8 favors geminiviral infection. Low levels of JAZ8 likely affect the viral infection specifically, since JAZ8-silenced plants neither display obvious developmental phenotypes nor present differences in their interaction with the viral insect vector. In summary, our results show that the geminivirus-encoded C2 interacts with JAZ8 in the nucleus, and suggest that this plant protein exerts an anti-geminiviral effect.
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Affiliation(s)
- Tabata Rosas-Diaz
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Universidad de Málaga, Málaga, Spain
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
| | - Pepe Cana-Quijada
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Universidad de Málaga, Málaga, Spain
| | - Mengshi Wu
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
| | - Du Hui
- Institute of Insect Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Gemma Fernandez-Barbero
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas, Madrid, 28049, Spain
| | - Alberto P Macho
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
| | - Roberto Solano
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas, Madrid, 28049, Spain
| | - Araceli G Castillo
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Universidad de Málaga, Málaga, Spain
| | - Xiao-Wei Wang
- Institute of Insect Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Rosa Lozano-Duran
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
- Department of Plant Biochemistry, Centre for Plant Molecular Biology, Eberhard Karls University, Tübingen, D-72076, Germany
| | - Eduardo R Bejarano
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Universidad de Málaga, Málaga, Spain
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39
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Matsumura EE, Kormelink R. Small Talk: On the Possible Role of Trans-Kingdom Small RNAs during Plant-Virus-Vector Tritrophic Communication. PLANTS (BASEL, SWITZERLAND) 2023; 12:1411. [PMID: 36987098 PMCID: PMC10059270 DOI: 10.3390/plants12061411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 06/19/2023]
Abstract
Small RNAs (sRNAs) are the hallmark and main effectors of RNA silencing and therefore are involved in major biological processes in plants, such as regulation of gene expression, antiviral defense, and plant genome integrity. The mechanisms of sRNA amplification as well as their mobile nature and rapid generation suggest sRNAs as potential key modulators of intercellular and interspecies communication in plant-pathogen-pest interactions. Plant endogenous sRNAs can act in cis to regulate plant innate immunity against pathogens, or in trans to silence pathogens' messenger RNAs (mRNAs) and impair virulence. Likewise, pathogen-derived sRNAs can act in cis to regulate expression of their own genes and increase virulence towards a plant host, or in trans to silence plant mRNAs and interfere with host defense. In plant viral diseases, virus infection alters the composition and abundance of sRNAs in plant cells, not only by triggering and interfering with the plant RNA silencing antiviral response, which accumulates virus-derived small interfering RNAs (vsiRNAs), but also by modulating plant endogenous sRNAs. Here, we review the current knowledge on the nature and activity of virus-responsive sRNAs during virus-plant interactions and discuss their role in trans-kingdom modulation of virus vectors for the benefit of virus dissemination.
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40
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Silencing suppressor protein PRT of rice tungro bacilliform virus interacts with the plant RNA silencing-related protein SGS3. Virology 2023; 581:71-80. [PMID: 36921478 DOI: 10.1016/j.virol.2023.02.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 02/16/2023] [Accepted: 02/22/2023] [Indexed: 03/08/2023]
Abstract
BACKGROUND Rice tungro bacilliform virus (RTBV) is a double stranded DNA containing virus which causes the devastating tungro disease of rice in association with an RNA virus, rice tungro spherical virus. RNA silencing is an evolutionarily conserved antiviral defence pathway in plants as well as in several classes of higher organisms. Many viruses, in turn, encode proteins which are termed Viral Suppressor of RNA Silencing (VSR) because they downregulate or suppress RNA silencing. RESULTS Using an RNA silencing suppressor assay we show that RTBV protease (PRT) acts as a mild VSR. A truncated version of PRT gene abolished the silencing suppression activity. We also show in planta interaction of PRT with the SGS3 protein of Solanum tuberosum and Arabidopsis thaliana using bimolecular fluorescence complementation assay (BIFC). Transient expression of PRT in Nicotiana benthamiana caused an increased accumulation of the begomovirus Sri Lankan cassava mosaic virus (SLCMV) DNA-A, which indicated a virulence function imparted on an unrelated virus. CONCLUSION The finding supports the idea that PRT acts as suppressor of RNA silencing and this action may be mediated by its interaction with SGS3.
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Guzmán-Benito I, Achkar NP, Bologna N, Ursache R. CRISPR/Cas-mediated inplanta gene targeting: current advances and challenges. JOURNAL OF EXPERIMENTAL BOTANY 2023:erad072. [PMID: 36861321 DOI: 10.1093/jxb/erad072] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Indexed: 06/18/2023]
Abstract
We can use gene targeting (GT) to make modifications at a specific region in a plant's genome and create high-precision tools for plant biotechnology and breeding. However, its low efficiency is a major barrier to its use in plants. The discovery of CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-Cas-based site-specific nucleases capable of inducing double-strand breaks in desired loci resulted in the development of novel approaches for plant GT. Several studies have recently demonstrated improvements in GT efficiency through cell-type-specific expression of Cas nucleases, the use of self-amplified GT-vector DNA, or manipulation of RNA silencing and DNA repair pathways. In this review, we summarize recent advances in CRISPR/Cas-mediated GT in plants and discuss potential efficiency improvements. Increasing the efficiency of GT technology will help us pave the way for increased crop yields and food safety in environmentally friendly agriculture.
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Affiliation(s)
- Irene Guzmán-Benito
- The Department of Plant Molecular Biology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Natalia Patricia Achkar
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Bellaterra, Barcelona 08193, Spain
| | - Nicolas Bologna
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Bellaterra, Barcelona 08193, Spain
| | - Robertas Ursache
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Bellaterra, Barcelona 08193, Spain
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42
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Kumar R, Dasgupta I. Geminiviral C4/AC4 proteins: An emerging component of the viral arsenal against plant defence. Virology 2023; 579:156-168. [PMID: 36693289 DOI: 10.1016/j.virol.2023.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 12/26/2022] [Accepted: 01/08/2023] [Indexed: 01/12/2023]
Abstract
Virus infection triggers a plethora of defence reactions in plants to incapacitate the intruder. Viruses, in turn, have added additional functions to their genes so that they acquire capabilities to neutralize the above defence reactions. In plant-infecting viruses, the family Geminiviridae comprises members, majority of whom encode 6-8 genes in their small single-stranded DNA genomes. Of the above genes, one which shows the most variability in its amino acid sequence is the C4/AC4. Recent studies have uncovered evidence, which point towards a wide repertoire of functions performed by C4/AC4 revealing its role as a major player in suppressing plant defence. This review summarizes the various plant defence mechanisms against viruses and highlights how C4/AC4 has evolved to counter most of them.
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Affiliation(s)
- Rohit Kumar
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Indranil Dasgupta
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.
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43
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Vaisman M, Hak H, Arazi T, Spiegelman Z. The Impact of Tobamovirus Infection on Root Development Involves Induction of Auxin Response Factor 10a in Tomato. PLANT & CELL PHYSIOLOGY 2023; 63:1980-1993. [PMID: 34977939 DOI: 10.1093/pcp/pcab179] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/16/2021] [Accepted: 01/02/2022] [Indexed: 06/14/2023]
Abstract
Plant viruses cause systemic diseases that severely impair plant growth and development. While the accumulation of viruses in the root system has long been established, little is known as to how viruses affect root architecture. Here, we examined how the emerging tobamovirus, tomato brown rugose fruit virus (ToBRFV), alters root development in tomato. We found that ToBRFV and tobacco mosaic virus both invaded root systems during the first week of infection. ToBRFV infection of tomato plants resulted in a significant decrease in root biomass and elongation and root-to-shoot ratio and a marked suppression of root branching. Mutation in RNA-dependent RNA polymerase 6 increased the susceptibility of tomato plants to ToBRFV, resulting in severe reduction of various root growth parameters including root branching. Viral root symptoms were associated with the accumulation of auxin response factor 10a (SlARF10a) transcript, a homolog of Arabidopsis ARF10, a known suppressor of lateral root development. Interestingly, loss-of-function mutation in SlARF10a moderated the effect of ToBRFV on root branching. In contrast, downregulation of sly-miR160a, which targets SlARF10a, was associated with constitutive suppression root branching independent of viral infection. In addition, overexpression of a microRNA-insensitive mutant of SlARF10a mimicked the effect of ToBRFV on root development, suggesting a specific role for SlARF10a in ToBRFV-mediated suppression of root branching. Taken together, our results provide new insights into the impact of tobamoviruses on root development and the role of ARF10a in the suppression of root branching in tomato.
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Affiliation(s)
- Michael Vaisman
- Department of Plant Pathology and Weed Research, Agricultural Research Organization-The Volcani Institute, 68 HaMaccabim Road, P.O.B 15159, Rishon LeZion 7505101, Israel
- The Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University of Jerusalem, PO Box 12, Rehovot 761001, Israel
| | - Hagit Hak
- Department of Plant Pathology and Weed Research, Agricultural Research Organization-The Volcani Institute, 68 HaMaccabim Road, P.O.B 15159, Rishon LeZion 7505101, Israel
| | - Tzahi Arazi
- Plant Sciences Institute, Agricultural Research Organization, The Volcani Institute, 68 HaMaccabim Road, P.O.B 15159, Rishon LeZion 7505101, Israel
| | - Ziv Spiegelman
- Department of Plant Pathology and Weed Research, Agricultural Research Organization-The Volcani Institute, 68 HaMaccabim Road, P.O.B 15159, Rishon LeZion 7505101, Israel
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44
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Sehki H, Yu A, Elmayan T, Vaucheret H. TYMV and TRV infect Arabidopsis thaliana by expressing weak suppressors of RNA silencing and inducing host RNASE THREE LIKE1. PLoS Pathog 2023; 19:e1010482. [PMID: 36696453 PMCID: PMC9901757 DOI: 10.1371/journal.ppat.1010482] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 02/06/2023] [Accepted: 01/10/2023] [Indexed: 01/26/2023] Open
Abstract
Post-Transcriptional Gene Silencing (PTGS) is a defense mechanism that targets invading nucleic acids of endogenous (transposons) or exogenous (pathogens, transgenes) origins. During plant infection by viruses, virus-derived primary siRNAs target viral RNAs, resulting in both destruction of single-stranded viral RNAs (execution step) and production of secondary siRNAs (amplification step), which maximizes the plant defense. As a counter-defense, viruses express proteins referred to as Viral Suppressor of RNA silencing (VSR). Some viruses express VSRs that totally inhibit PTGS, whereas other viruses express VSRs that have limited effect. Here we show that infection with the Turnip yellow mosaic virus (TYMV) is enhanced in Arabidopsis ago1, ago2 and dcl4 mutants, which are impaired in the execution of PTGS, but not in dcl2, rdr1 and rdr6 mutants, which are impaired in the amplification of PTGS. Consistently, we show that the TYMV VSR P69 localizes in siRNA-bodies, which are the site of production of secondary siRNAs, and limits PTGS amplification. Moreover, TYMV induces the production of the host enzyme RNASE THREE-LIKE 1 (RTL1) to further reduce siRNA accumulation. Infection with the Tobacco rattle virus (TRV), which also encodes a VSR limiting PTGS amplification, induces RTL1 as well to reduce siRNA accumulation and promote infection. Together, these results suggest that RTL1 could be considered as a host susceptibility gene that is induced by viruses as a strategy to further limit the plant PTGS defense when VSRs are insufficient.
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Affiliation(s)
- Hayat Sehki
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
- Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Agnès Yu
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Taline Elmayan
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Hervé Vaucheret
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
- * E-mail:
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45
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Feng C, Torimaru K, Lim MYT, Chak LL, Shiimori M, Tsuji K, Tanaka T, Iida J, Okamura K. A novel eukaryotic RdRP-dependent small RNA pathway represses antiviral immunity by controlling an ERK pathway component in the black-legged tick. PLoS One 2023; 18:e0281195. [PMID: 36996253 PMCID: PMC10062562 DOI: 10.1371/journal.pone.0281195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 01/17/2023] [Indexed: 04/01/2023] Open
Abstract
Small regulatory RNAs (sRNAs) are involved in antiviral defense and gene regulation. Although roles of RNA-dependent RNA Polymerases (RdRPs) in sRNA biology are extensively studied in nematodes, plants and fungi, understanding of RdRP homologs in other animals is still lacking. Here, we study sRNAs in the ISE6 cell line, which is derived from the black-legged tick, an important vector of human and animal pathogens. We find abundant classes of ~22nt sRNAs that require specific combinations of RdRPs and sRNA effector proteins (Argonautes or AGOs). RdRP1-dependent sRNAs possess 5'-monophosphates and are mainly derived from RNA polymerase III-transcribed genes and repetitive elements. Knockdown of some RdRP homologs misregulates genes including RNAi-related genes and the regulator of immune response Dsor1. Sensor assays demonstrate that Dsor1 is downregulated by RdRP1 through the 3'UTR that contains a target site of RdRP1-dependent repeat-derived sRNAs. Consistent with viral gene repression by the RNAi mechanism using virus-derived small interfering RNAs, viral transcripts are upregulated by AGO knockdown. On the other hand, RdRP1 knockdown unexpectedly results in downregulation of viral transcripts. This effect is dependent on Dsor1, suggesting that antiviral immunity is enhanced by RdRP1 knockdown through Dsor1 upregulation. We propose that tick sRNA pathways control multiple aspects of immune response via RNAi and regulation of signaling pathways.
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Affiliation(s)
- Canran Feng
- Nara Institute of Science and Technology, Nara, Japan
| | | | - Mandy Yu Theng Lim
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Li-Ling Chak
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, Singapore
| | | | - Kosuke Tsuji
- Nara Institute of Science and Technology, Nara, Japan
| | - Tetsuya Tanaka
- Joint Faculty of Veterinary Medicine, Laboratory of Infectious Diseases, Kagoshima University, Kagoshima, Japan
| | - Junko Iida
- Nara Institute of Science and Technology, Nara, Japan
| | - Katsutomo Okamura
- Nara Institute of Science and Technology, Nara, Japan
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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46
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Akbarimotlagh M, Azizi A, Shams-Bakhsh M, Jafari M, Ghasemzadeh A, Palukaitis P. Critical points for the design and application of RNA silencing constructs for plant virus resistance. Adv Virus Res 2023; 115:159-203. [PMID: 37173065 DOI: 10.1016/bs.aivir.2023.02.001] [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: 05/15/2023]
Abstract
Control of plant virus diseases is a big challenge in agriculture as is resistance in plant lines to infection by viruses. Recent progress using advanced technologies has provided fast and durable alternatives. One of the most promising techniques against plant viruses that is cost-effective and environmentally safe is RNA silencing or RNA interference (RNAi), a technology that could be used alone or along with other control methods. To achieve the goals of fast and durable resistance, the expressed and target RNAs have been examined in many studies, with regard to the variability in silencing efficiency, which is regulated by various factors such as target sequences, target accessibility, RNA secondary structures, sequence variation in matching positions, and other intrinsic characteristics of various small RNAs. Developing a comprehensive and applicable toolbox for the prediction and construction of RNAi helps researchers to achieve the acceptable performance level of silencing elements. Although the attainment of complete prediction of RNAi robustness is not possible, as it also depends on the cellular genetic background and the nature of the target sequences, some important critical points have been discerned. Thus, the efficiency and robustness of RNA silencing against viruses can be improved by considering the various parameters of the target sequence and the construct design. In this review, we provide a comprehensive treatise regarding past, present and future prospective developments toward designing and applying RNAi constructs for resistance to plant viruses.
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Affiliation(s)
- Masoud Akbarimotlagh
- Plant Pathology Department, Faculty of Agriculture, Tarbiat Modares University (TMU), Tehran, Iran
| | - Abdolbaset Azizi
- Department of Plant Protection, Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran.
| | - Masoud Shams-Bakhsh
- Plant Pathology Department, Faculty of Agriculture, Tarbiat Modares University (TMU), Tehran, Iran
| | - Majid Jafari
- Department of Plant Protection, Higher Education Complex of Saravan, Saravan, Iran
| | - Aysan Ghasemzadeh
- Plant Pathology Department, Faculty of Agriculture, Tarbiat Modares University (TMU), Tehran, Iran
| | - Peter Palukaitis
- Department of Horticulture Sciences, Seoul Women's University, Seoul, Republic of Korea.
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47
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Assessment of the RNA Silencing Suppressor Activity of Protein P0 of Pepper Vein Yellows Virus 5: Uncovering Natural Variability, Relevant Motifs and Underlying Mechanism. BIOLOGY 2022; 11:biology11121801. [PMID: 36552310 PMCID: PMC9775047 DOI: 10.3390/biology11121801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/02/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022]
Abstract
Pepper vein yellows virus 5 (PeVYV-5) belongs to a group of emerging poleroviruses (family Solemoviridae) which pose a risk to pepper cultivation worldwide. Since its first detection in Spain in 2013 and the determination of the complete genome sequence of an isolate in 2018, little is known on the presence, genomic variation and molecular properties of this pathogen. As other members of genus Polerovirus, PeVYV-5 encodes a P0 protein that was predicted to act as viral suppressor of RNA silencing (VSR), one of the major antiviral defense mechanisms in plants. The results of the present work have indicated that PeVYV-5 P0 is a potent VSR, which is able to induce the degradation of Argonaute (AGO) endonucleases, the main effectors of RNA silencing. New viral isolates have been identified in samples collected in 2020-2021 and sequencing of their P0 gene has revealed limited heterogeneity, suggesting that the protein is under negative selection. Analysis of natural and engineered P0 variants has pinpointed distinct protein motifs as critical for the VSR role. Moreover, a positive correlation between the VSR activity of the protein and its capability to promote AGO degradation could be established, supporting that such activity essentially relies on the clearance of core components of the RNA silencing machinery.
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48
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Bahari A, Castillo AG, Safaie N, Bejarano ER, Luna AP, Shams-Bakhsh M. Functional Analysis of V2 Protein of Beet Curly Top Iran Virus. PLANTS (BASEL, SWITZERLAND) 2022; 11:3351. [PMID: 36501393 PMCID: PMC9736138 DOI: 10.3390/plants11233351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/23/2022] [Accepted: 11/26/2022] [Indexed: 06/17/2023]
Abstract
Geminivirus beet curly top Iran virus (BCTIV) is one of the main causal agents of the beet curly top disease in Iran and the newly established Becurtovirus genus type species. Although the biological features of known becurtoviruses are similar to those of curtoviruses, they only share a limited sequence identity, and no information is available on the function of their viral genes. In this work, we demonstrate that BCTIV V2, as the curtoviral V2, is also a local silencing suppressor in Nicotiana benthamiana and can delay the systemic silencing spreading, although it cannot block the cell-to-cell movement of the silencing signal to adjacent cells. BCTIV V2 shows the same subcellular localization as curtoviral V2, being detected in the nucleus and perinuclear region, and its ectopic expression from a PVX-derived vector also causes the induction of necrotic lesions in N. benthamiana, such as the ones produced during the HR, both at the local and systemic levels. The results from the infection of N. benthamiana with a V2 BCTIV mutant showed that V2 is required for systemic infection, but not for viral replication, in a local infection. Considering all these results, we can conclude that BCTIV V2 is a functional homologue of curtoviral V2 and plays a crucial role in viral pathogenicity and systemic movement.
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Affiliation(s)
- Atiyeh Bahari
- Plant Pathology Department, Faculty of Agriculture, Tarbiat Modares University (TMU), Tehran 336-14115, Iran
| | - Araceli G. Castillo
- Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento Biología Celular, Genética y Fisiología, Universidad de Málaga, 29010 Malaga, Spain
| | - Naser Safaie
- Plant Pathology Department, Faculty of Agriculture, Tarbiat Modares University (TMU), Tehran 336-14115, Iran
| | - Eduardo R. Bejarano
- Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento Biología Celular, Genética y Fisiología, Universidad de Málaga, 29010 Malaga, Spain
| | - Ana P. Luna
- Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento Biología Celular, Genética y Fisiología, Universidad de Málaga, 29010 Malaga, Spain
| | - Masoud Shams-Bakhsh
- Plant Pathology Department, Faculty of Agriculture, Tarbiat Modares University (TMU), Tehran 336-14115, Iran
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49
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Yan Y. Insights into Mobile Small-RNAs Mediated Signaling in Plants. PLANTS (BASEL, SWITZERLAND) 2022; 11:3155. [PMID: 36432884 PMCID: PMC9698838 DOI: 10.3390/plants11223155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/07/2022] [Accepted: 11/09/2022] [Indexed: 06/16/2023]
Abstract
In higher plants, small RNA (sRNA)-mediated RNA interfering (RNAi) is involved in a broad range of biological processes. Growing evidence supports the model that sRNAs are mobile signaling agents that move intercellularly, systemically and cross-species. Recently, considerable progress has been made in terms of characterization of the mobile sRNAs population and their function. In this review, recent progress in identification of new mobile sRNAs is assessed. Here, critical questions related to the function of these mobile sRNAs in coordinating developmental, physiological and defense-related processes is discussed. The forms of mobile sRNAs and the underlying mechanisms mediating sRNA trafficking are discussed next. A concerted effort has been made to integrate these new findings into a comprehensive overview of mobile sRNAs signaling in plants. Finally, potential important areas for both basic science and potential applications are highlighted for future research.
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Affiliation(s)
- Yan Yan
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
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50
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Kong X, Yang M, Le BH, He W, Hou Y. The master role of siRNAs in plant immunity. MOLECULAR PLANT PATHOLOGY 2022; 23:1565-1574. [PMID: 35869407 PMCID: PMC9452763 DOI: 10.1111/mpp.13250] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 06/18/2022] [Accepted: 06/21/2022] [Indexed: 06/01/2023]
Abstract
Gene silencing mediated by small noncoding RNAs (sRNAs) is a fundamental gene regulation mechanism in eukaryotes that broadly governs cellular processes. It has been established that sRNAs are critical regulators of plant growth, development, and antiviral defence, while accumulating studies support positive roles of sRNAs in plant defence against bacteria and eukaryotic pathogens such as fungi and oomycetes. Emerging evidence suggests that plant sRNAs move between species and function as antimicrobial agents against nonviral parasites. Multiple plant pathosystems have been shown to involve a similar exchange of small RNAs between species. Recent analysis about extracellular sRNAs shed light on the understanding of the selection and transportation of sRNAs moving from plant to parasites. In this review, we summarize current advances regarding the function and regulatory mechanism of plant endogenous small interfering RNAs (siRNAs) in mediating plant defence against pathogen intruders including viruses, bacteria, fungi, oomycetes, and parasitic plants. Beyond that, we propose potential mechanisms behind the sorting of sRNAs moving between species and the idea that engineering siRNA-producing loci could be a useful strategy to improve disease resistance of crops.
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Affiliation(s)
- Xiuzhen Kong
- Shanghai Collaborative Innovation Center of Agri‐Seeds/School of Agriculture and BiologyShanghai Jiao Tong UniversityShanghaiChina
| | - Meng Yang
- Shanghai Collaborative Innovation Center of Agri‐Seeds/School of Agriculture and BiologyShanghai Jiao Tong UniversityShanghaiChina
| | - Brandon H. Le
- Department of Botany and Plant Sciences, Institute of Integrative Genome BiologyUniversity of CaliforniaRiversideCaliforniaUSA
| | - Wenrong He
- Plant Molecular and Cellular Biology LaboratorySalk Institute for Biological StudiesLa JollaCaliforniaUSA
| | - Yingnan Hou
- Shanghai Collaborative Innovation Center of Agri‐Seeds/School of Agriculture and BiologyShanghai Jiao Tong UniversityShanghaiChina
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