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Carr JP. Engineered Resistance to Tobamoviruses. Viruses 2024; 16:1007. [PMID: 39066170 PMCID: PMC11281658 DOI: 10.3390/v16071007] [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: 05/29/2024] [Revised: 06/17/2024] [Accepted: 06/19/2024] [Indexed: 07/28/2024] Open
Abstract
Tobacco mosaic virus (TMV) was the first virus to be studied in detail and, for many years, TMV and other tobamoviruses, particularly tomato mosaic virus (ToMV) and tobamoviruses infecting pepper (Capsicum spp.), were serious crop pathogens. By the end of the twentieth and for the first decade of the twenty-first century, tobamoviruses were under some degree of control due to introgression of resistance genes into commercial tomato and pepper lines. However, tobamoviruses remained important models for molecular biology, biotechnology and bio-nanotechnology. Recently, tobamoviruses have again become serious crop pathogens due to the advent of tomato brown rugose fruit virus, which overcomes tomato resistance against TMV and ToMV, and the slow but apparently inexorable worldwide spread of cucumber green mottle mosaic virus, which threatens all cucurbit crops. This review discusses a range of mainly molecular biology-based approaches for protecting crops against tobamoviruses. These include cross-protection (using mild tobamovirus strains to 'immunize' plants against severe strains), expressing viral gene products in transgenic plants to inhibit the viral infection cycle, inducing RNA silencing against tobamoviruses by expressing virus-derived RNA sequences in planta or by direct application of double-stranded RNA molecules to non-engineered plants, gene editing of host susceptibility factors, and the transfer and optimization of natural resistance genes.
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Affiliation(s)
- John Peter Carr
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
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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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Crawshaw S, Murphy AM, Rowling PJE, Nietlispach D, Itzhaki LS, Carr JP. Investigating the Interactions of the Cucumber Mosaic Virus 2b Protein with the Viral 1a Replicase Component and the Cellular RNA Silencing Factor Argonaute 1. Viruses 2024; 16:676. [PMID: 38793558 PMCID: PMC11125589 DOI: 10.3390/v16050676] [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: 03/16/2024] [Revised: 04/13/2024] [Accepted: 04/16/2024] [Indexed: 05/26/2024] Open
Abstract
The cucumber mosaic virus (CMV) 2b protein is a suppressor of plant defenses and a pathogenicity determinant. Amongst the 2b protein's host targets is the RNA silencing factor Argonaute 1 (AGO1), which it binds to and inhibits. In Arabidopsis thaliana, if 2b-induced inhibition of AGO1 is too efficient, it induces reinforcement of antiviral silencing by AGO2 and triggers increased resistance against aphids, CMV's insect vectors. These effects would be deleterious to CMV replication and transmission, respectively, but are moderated by the CMV 1a protein, which sequesters sufficient 2b protein molecules into P-bodies to prevent excessive inhibition of AGO1. Mutant 2b protein variants were generated, and red and green fluorescent protein fusions were used to investigate subcellular colocalization with AGO1 and the 1a protein. The effects of mutations on complex formation with the 1a protein and AGO1 were investigated using bimolecular fluorescence complementation and co-immunoprecipitation assays. Although we found that residues 56-60 influenced the 2b protein's interactions with the 1a protein and AGO1, it appears unlikely that any single residue or sequence domain is solely responsible. In silico predictions of intrinsic disorder within the 2b protein secondary structure were supported by circular dichroism (CD) but not by nuclear magnetic resonance (NMR) spectroscopy. Intrinsic disorder provides a plausible model to explain the 2b protein's ability to interact with AGO1, the 1a protein, and other factors. However, the reasons for the conflicting conclusions provided by CD and NMR must first be resolved.
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Affiliation(s)
- Sam Crawshaw
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; (S.C.); (A.M.M.)
| | - Alex M. Murphy
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; (S.C.); (A.M.M.)
| | - Pamela J. E. Rowling
- Department of Pharmacology, University of Cambridge, Tennis Court Rd., Cambridge CB2 1PD, UK; (P.J.E.R.); (L.S.I.)
| | - Daniel Nietlispach
- Department of Biochemistry, University of Cambridge, Sanger Building, 80 Tennis Court Rd., Cambridge CB2 1GA, UK;
| | - Laura S. Itzhaki
- Department of Pharmacology, University of Cambridge, Tennis Court Rd., Cambridge CB2 1PD, UK; (P.J.E.R.); (L.S.I.)
| | - John P. Carr
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; (S.C.); (A.M.M.)
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Chooi KM, Bell VA, Blouin AG, Sandanayaka M, Gough R, Chhagan A, MacDiarmid RM. The New Zealand perspective of an ecosystem biology response to grapevine leafroll disease. Adv Virus Res 2024; 118:213-272. [PMID: 38461030 DOI: 10.1016/bs.aivir.2024.02.001] [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: 03/11/2024]
Abstract
Grapevine leafroll-associated virus 3 (GLRaV-3) is a major pathogen of grapevines worldwide resulting in grapevine leafroll disease (GLD), reduced fruit yield, berry quality and vineyard profitability. Being graft transmissible, GLRaV-3 is also transmitted between grapevines by multiple hemipteran insects (mealybugs and soft scale insects). Over the past 20 years, New Zealand has developed and utilized integrated pest management (IPM) solutions that have slowly transitioned to an ecosystem-based biological response to GLD. These IPM solutions and combinations are based on a wealth of research within the temperate climates of New Zealand's nation-wide grape production. To provide context, the grapevine viruses present in the national vineyard estate and how these have been identified are described; the most pathogenic and destructive of these is GLRaV-3. We provide an overview of research on GLRaV-3 genotypes and biology within grapevines and describe the progressive development of GLRaV-3/GLD diagnostics based on molecular, serological, visual, and sensor-based technologies. Research on the ecology and control of the mealybugs Pseudococcus calceolariae and P. longispinus, the main insect vectors of GLRaV-3 in New Zealand, is described together with the implications of mealybug biological control agents and prospects to enhance their abundance and/or fitness in the vineyard. Virus transmission by mealybugs is described, with emphasis on understanding the interactions between GLRaV-3, vectors, and plants (grapevines, alternative hosts, or non-hosts of the virus). Disease management through grapevine removal and the economic influence of different removal strategies is detailed. Overall, the review summarizes research by an interdisciplinary team working in close association with the national industry body, New Zealand Winegrowers. Teamwork and communication across the whole industry has enabled implementation of research for the management of GLD.
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Affiliation(s)
- Kar Mun Chooi
- The New Zealand Institute for Plant & Food Research Limited, Auckland, New Zealand
| | - Vaughn A Bell
- The New Zealand Institute for Plant and Food Research Limited, Havelock North, New Zealand.
| | | | | | - Rebecca Gough
- The New Zealand Institute for Plant & Food Research Limited, Auckland, New Zealand
| | - Asha Chhagan
- The New Zealand Institute for Plant & Food Research Limited, Auckland, New Zealand
| | - Robin M MacDiarmid
- The New Zealand Institute for Plant & Food Research Limited, Auckland, New Zealand; The University of Auckland, Auckland, New Zealand
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Palukaitis P, Yoon JY. Defense signaling pathways in resistance to plant viruses: Crosstalk and finger pointing. Adv Virus Res 2024; 118:77-212. [PMID: 38461031 DOI: 10.1016/bs.aivir.2024.01.002] [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: 03/11/2024]
Abstract
Resistance to infection by plant viruses involves proteins encoded by plant resistance (R) genes, viz., nucleotide-binding leucine-rich repeats (NLRs), immune receptors. These sensor NLRs are activated either directly or indirectly by viral protein effectors, in effector-triggered immunity, leading to induction of defense signaling pathways, resulting in the synthesis of numerous downstream plant effector molecules that inhibit different stages of the infection cycle, as well as the induction of cell death responses mediated by helper NLRs. Early events in this process involve recognition of the activation of the R gene response by various chaperones and the transport of these complexes to the sites of subsequent events. These events include activation of several kinase cascade pathways, and the syntheses of two master transcriptional regulators, EDS1 and NPR1, as well as the phytohormones salicylic acid, jasmonic acid, and ethylene. The phytohormones, which transit from a primed, resting states to active states, regulate the remainder of the defense signaling pathways, both directly and by crosstalk with each other. This regulation results in the turnover of various suppressors of downstream events and the synthesis of various transcription factors that cooperate and/or compete to induce or suppress transcription of either other regulatory proteins, or plant effector molecules. This network of interactions results in the production of defense effectors acting alone or together with cell death in the infected region, with or without the further activation of non-specific, long-distance resistance. Here, we review the current state of knowledge regarding these processes and the components of the local responses, their interactions, regulation, and crosstalk.
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Affiliation(s)
- Peter Palukaitis
- Graduate School of Plant Protection and Quarantine, Jeonbuk National University, Jeonju, Jeollabuk-do, Republic of Korea.
| | - Ju-Yeon Yoon
- Graduate School of Plant Protection and Quarantine, Jeonbuk National University, Jeonju, Jeollabuk-do, Republic of Korea.
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Ahmed R, Kaldis A, Voloudakis A. Silencing of a Nicotiana benthamiana ascorbate oxidase gene reveals its involvement in resistance against cucumber mosaic virus. PLANTA 2024; 259:38. [PMID: 38227024 PMCID: PMC10791908 DOI: 10.1007/s00425-023-04313-x] [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: 10/06/2023] [Accepted: 12/13/2023] [Indexed: 01/17/2024]
Abstract
MAIN CONCLUSION Silencing of an ascorbate oxidase (AO) gene in N. benthamiana enhanced disease severity from cucumber mosaic virus (CMV), showing higher accumulation and expansion of the spreading area of CMV. A Nicotiana benthamiana ascorbate oxidase (NbAO) gene was found to be induced upon cucumber mosaic virus (CMV) infection. Virus-induced gene silencing (VIGS) was employed to elucidate the function of AO in N. benthamiana. The tobacco rattle virus (TRV)-mediated VIGS resulted in an efficient silencing of the NbAO gene, i.e., 97.5% and 78.8% in relative quantification as compared to the control groups (TRV::eGFP- and the mock-inoculated plants), respectively. In addition, AO enzymatic activity decreased in the TRV::NtAO-silenced plants as compared to control. TRV::NtAO-mediated NbAO silencing induced a greater reduction in plant height by 15.2% upon CMV infection. CMV titer at 3 dpi was increased in the systemic leaves of NbAO-silenced plants (a 35-fold change difference as compared to the TRV::eGFP-treated group). Interestingly, CMV and TRV titers vary in different parts of systemically infected N. benthamiana leaves. In TRV::eGFP-treated plants, CMV accumulated only at the top half of the leaf, whereas the bottom half of the leaf was "occupied" by TRV. In contrast, in the NbAO-silenced plants, CMV accumulated in both the top and the bottom half of the leaf, suggesting that the silencing of the NbAO gene resulted in the expansion of the spreading area of CMV. Our data suggest that the AO gene might function as a resistant factor against CMV infection in N. benthamiana.
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Affiliation(s)
- Reshma Ahmed
- Laboratory of Plant Breeding and Biometry, Department of Crop Science, Agricultural University of Athens, 11855, Athens, Greece
- Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, Assam, 785013, India
| | - Athanasios Kaldis
- Laboratory of Plant Breeding and Biometry, Department of Crop Science, Agricultural University of Athens, 11855, Athens, Greece
| | - Andreas Voloudakis
- Laboratory of Plant Breeding and Biometry, Department of Crop Science, Agricultural University of Athens, 11855, Athens, Greece.
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Lovelock DA, Mintoff SJL, Kurz N, Neilsen M, Patel S, Constable FE, Tran-Nguyen LTT. Ability of Non-Hosts and Cucurbitaceous Weeds to Transmit Cucumber Green Mottle Mosaic Virus. Viruses 2023; 15:683. [PMID: 36992392 PMCID: PMC10056631 DOI: 10.3390/v15030683] [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: 01/16/2023] [Revised: 02/26/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
Cucumber green mottle mosaic virus (CGMMV) is a Tobamovirus of economic importance affecting cucurbit crops and Asian cucurbit vegetables. Non-host crops of CGMMV, including capsicum (Capsicum annum), sweetcorn (Zea mays), and okra (Abelmoschus esculentus), were tested for their susceptibility to the virus, with field and glasshouse trials undertaken. After 12 weeks post-sowing, the crops were tested for the presence of CGMMV, and in all cases, no CGMMV was detected. Commonly found within the growing regions of cucurbits and melons worldwide are weeds, such as black nightshade (Solanum nigrum), wild gooseberry (Physalis minima), pigweed (Portulaca oleracea), and Amaranth species. Several weeds/grasses were tested for their ability to become infected with CGMMV by inoculating weeds directly with CGMMV and routinely testing over a period of eight weeks. Amaranthus viridis was found to be susceptible, with 50% of the weeds becoming infected with CGMMV. To further analyse this, six Amaranth samples were used as inoculum on four watermelon seedlings per sample and tested after eight weeks. CGMMV was detected in three of six watermelon bulk samples, indicating that A. viridis is a potential host/reservoir for CGMMV. Further research into the relationship between CGMMV and weed hosts is required. This research also highlights the importance of proper weed management to effectively manage CGMMV.
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Affiliation(s)
- David A. Lovelock
- Department of Jobs Precincts and Regions, Agriculture Victoria Research, Agribio, Melbourne, VIC 3083, Australia;
| | - Sharl J. L. Mintoff
- Department of Industry, Tourism and Trade, Biosecurity and Animal Welfare, Darwin, NT 0801, Australia; (S.J.L.M.); (N.K.); (M.N.); (S.P.)
| | - Nadine Kurz
- Department of Industry, Tourism and Trade, Biosecurity and Animal Welfare, Darwin, NT 0801, Australia; (S.J.L.M.); (N.K.); (M.N.); (S.P.)
| | - Merran Neilsen
- Department of Industry, Tourism and Trade, Biosecurity and Animal Welfare, Darwin, NT 0801, Australia; (S.J.L.M.); (N.K.); (M.N.); (S.P.)
| | - Shreya Patel
- Department of Industry, Tourism and Trade, Biosecurity and Animal Welfare, Darwin, NT 0801, Australia; (S.J.L.M.); (N.K.); (M.N.); (S.P.)
| | - Fiona E. Constable
- Department of Jobs Precincts and Regions, Agriculture Victoria Research, Agribio, Melbourne, VIC 3083, Australia;
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The Key Roles of ROS and RNS as a Signaling Molecule in Plant-Microbe Interactions. Antioxidants (Basel) 2023; 12:antiox12020268. [PMID: 36829828 PMCID: PMC9952064 DOI: 10.3390/antiox12020268] [Citation(s) in RCA: 34] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/13/2023] [Accepted: 01/24/2023] [Indexed: 01/27/2023] Open
Abstract
Reactive oxygen species (ROS) and reactive nitrogen species (RNS) play a pivotal role in the dynamic cell signaling systems in plants, even under biotic and abiotic stress conditions. Over the past two decades, various studies have endorsed the notion that these molecules can act as intracellular and intercellular signaling molecules at a very low concentration to control plant growth and development, symbiotic association, and defense mechanisms in response to biotic and abiotic stress conditions. However, the upsurge of ROS and RNS under stressful conditions can lead to cell damage, retarded growth, and delayed development of plants. As signaling molecules, ROS and RNS have gained great attention from plant scientists and have been studied under different developmental stages of plants. However, the role of RNS and RNS signaling in plant-microbe interactions is still unknown. Different organelles of plant cells contain the enzymes necessary for the formation of ROS and RNS as well as their scavengers, and the spatial and temporal positions of these enzymes determine the signaling pathways. In the present review, we aimed to report the production of ROS and RNS, their role as signaling molecules during plant-microbe interactions, and the antioxidant system as a balancing system in the synthesis and elimination of these species.
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Arinaitwe W, Guyon A, Tungadi TD, Cunniffe NJ, Rhee SJ, Khalaf A, Mhlanga NM, Pate AE, Murphy AM, Carr JP. The Effects of Cucumber Mosaic Virus and Its 2a and 2b Proteins on Interactions of Tomato Plants with the Aphid Vectors Myzus persicae and Macrosiphum euphorbiae. Viruses 2022; 14:v14081703. [PMID: 36016326 PMCID: PMC9416248 DOI: 10.3390/v14081703] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 07/26/2022] [Accepted: 07/28/2022] [Indexed: 02/02/2023] Open
Abstract
Cucumber mosaic virus (CMV), a major tomato pathogen, is aphid-vectored in the non-persistent manner. We investigated if CMV-induced volatile organic compounds (VOCs) or other virus-induced cues alter aphid-tomato interactions. Y-tube olfactometry showed that VOCs emitted by plants infected with CMV (strain Fny) attracted generalist (Myzus persicae) and Solanaceae specialist (Macrosiphum euphorbiae) aphids. Myzus persicae preferred settling on infected plants (3 days post-inoculation: dpi) at 1h post-release, but at 9 and 21 dpi, aphids preferentially settled on mock-inoculated plants. Macrosiphum euphorbiae showed no strong preference for mock-inoculated versus infected plants at 3 dpi but settled preferentially on mock-inoculated plants at 9 and 21 dpi. In darkness aphids showed no settling or migration bias towards either mock-inoculated or infected plants. However, tomato VOC blends differed in light and darkness, suggesting aphids respond to a complex mix of olfactory, visual, and other cues influenced by infection. The LS-CMV strain induced no changes in aphid-plant interactions. Experiments using inter-strain recombinant and pseudorecombinant viruses showed that the Fny-CMV 2a and 2b proteins modified tomato interactions with Macrosiphum euphorbiae and Myzus persicae, respectively. The defence signal salicylic acid prevents excessive CMV-induced damage to tomato plants but is not involved in CMV-induced changes in aphid-plant interactions.
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Affiliation(s)
- Warren Arinaitwe
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; (W.A.); (A.G.); (T.D.T.); (N.J.C.); (S.-J.R.); (A.K.); (N.M.M.); (A.E.P.); (A.M.M.)
- Alliance of Bioversity International and International Center for Tropical Agriculture (CIAT), Dong Dok, Ban Nongviengkham, Vientiane CB10 1RQ, Laos
| | - Alex Guyon
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; (W.A.); (A.G.); (T.D.T.); (N.J.C.); (S.-J.R.); (A.K.); (N.M.M.); (A.E.P.); (A.M.M.)
- Sainsbury Laboratory, Cambridge University, Bateman St, Cambridge CB2 1LR, UK
| | - Trisna D. Tungadi
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; (W.A.); (A.G.); (T.D.T.); (N.J.C.); (S.-J.R.); (A.K.); (N.M.M.); (A.E.P.); (A.M.M.)
- School of Life Sciences, Keele University, Newcastle ST5 5BG, UK
| | - Nik J. Cunniffe
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; (W.A.); (A.G.); (T.D.T.); (N.J.C.); (S.-J.R.); (A.K.); (N.M.M.); (A.E.P.); (A.M.M.)
| | - Sun-Ju Rhee
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; (W.A.); (A.G.); (T.D.T.); (N.J.C.); (S.-J.R.); (A.K.); (N.M.M.); (A.E.P.); (A.M.M.)
| | - Amjad Khalaf
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; (W.A.); (A.G.); (T.D.T.); (N.J.C.); (S.-J.R.); (A.K.); (N.M.M.); (A.E.P.); (A.M.M.)
- Wellcome Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Saffron Walden CB10 1RQ, UK
| | - Netsai M. Mhlanga
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; (W.A.); (A.G.); (T.D.T.); (N.J.C.); (S.-J.R.); (A.K.); (N.M.M.); (A.E.P.); (A.M.M.)
- National Institute for Agricultural Botany-East Malling (NIAB-EMR), West Malling ME19 6BJ, UK
| | - Adrienne E. Pate
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; (W.A.); (A.G.); (T.D.T.); (N.J.C.); (S.-J.R.); (A.K.); (N.M.M.); (A.E.P.); (A.M.M.)
| | - Alex M. Murphy
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; (W.A.); (A.G.); (T.D.T.); (N.J.C.); (S.-J.R.); (A.K.); (N.M.M.); (A.E.P.); (A.M.M.)
| | - John P. Carr
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; (W.A.); (A.G.); (T.D.T.); (N.J.C.); (S.-J.R.); (A.K.); (N.M.M.); (A.E.P.); (A.M.M.)
- Correspondence:
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Xu W, Li H, Sivasithamparam K, Tran DT, Jones MGK, Chen X, Wylie SJ. Spillover of a Tobamovirus from the Australian Indigenous Flora to Invasive Weeds. Viruses 2022; 14:v14081676. [PMID: 36016296 PMCID: PMC9413628 DOI: 10.3390/v14081676] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 07/25/2022] [Accepted: 07/28/2022] [Indexed: 11/17/2022] Open
Abstract
The tobamovirus yellow tailflower mild mottle virus (YTMMV) was previously reported in wild plants of Anthocercis species (family Solanaceae) and other solanaceous indigenous species growing in natural habitats in Western Australia. Here, we undertook a survey of two introduced solanaceous weeds, namely Solanum nigrum (black nightshade) and Physalis peruviana (cape gooseberry) in the Perth metropolitan area and surrounds to determine if YTMMV has spread naturally to these species. At a remnant natural bushland site where both solanaceous weeds and indigenous Anthocercis hosts grew adjacent to one another, a proportion of S. nigrum and P. peruviana plants were asymptomatically-infected with YTMMV, confirming spillover had occurred. Populations of S. nigrum also grow as weeds in parts of the city isolated from remnant bushland and indigenous sources of YTMMV, and some of these populations were also infected with YTMMV. Fruit was harvested from virus-infected wild S. nigrum plants and the seed germinated under controlled conditions. Up to 80% of resultant seedlings derived from infected parent plants were infected with YTMMV, confirming that the virus is vertically-transmitted in S. nigrum, and therefore infection appears to be self-sustaining in this species. This is the first report of spillover of YTMMV to exotic weeds, and of vertical transmission of this tobamovirus. We discuss the roles of vertical and horizontal transmission in this spillover event, and its implications for biosecurity.
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Affiliation(s)
- Weinan Xu
- Plant Biotechnology Research Group (Virology), Western Australian State Agricultural Biotechnology Centre, Murdoch University, 90 South Street, Murdoch 6150, Australia; (W.X.); (H.L.); (K.S.); (D.T.T.); (M.G.K.J.)
- Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Hua Li
- Plant Biotechnology Research Group (Virology), Western Australian State Agricultural Biotechnology Centre, Murdoch University, 90 South Street, Murdoch 6150, Australia; (W.X.); (H.L.); (K.S.); (D.T.T.); (M.G.K.J.)
| | - Krishnapillai Sivasithamparam
- Plant Biotechnology Research Group (Virology), Western Australian State Agricultural Biotechnology Centre, Murdoch University, 90 South Street, Murdoch 6150, Australia; (W.X.); (H.L.); (K.S.); (D.T.T.); (M.G.K.J.)
| | - Dieu Thi Tran
- Plant Biotechnology Research Group (Virology), Western Australian State Agricultural Biotechnology Centre, Murdoch University, 90 South Street, Murdoch 6150, Australia; (W.X.); (H.L.); (K.S.); (D.T.T.); (M.G.K.J.)
| | - Michael G. K. Jones
- Plant Biotechnology Research Group (Virology), Western Australian State Agricultural Biotechnology Centre, Murdoch University, 90 South Street, Murdoch 6150, Australia; (W.X.); (H.L.); (K.S.); (D.T.T.); (M.G.K.J.)
| | - Xin Chen
- Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
- Correspondence: (X.C.); or (S.J.W.)
| | - Stephen J. Wylie
- Plant Biotechnology Research Group (Virology), Western Australian State Agricultural Biotechnology Centre, Murdoch University, 90 South Street, Murdoch 6150, Australia; (W.X.); (H.L.); (K.S.); (D.T.T.); (M.G.K.J.)
- Correspondence: (X.C.); or (S.J.W.)
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11
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Wylie S, Li H. Historical and Scientific Evidence for the Origin and Cultural Importance to Australia's First-Nations Peoples of the Laboratory Accession of Nicotiana benthamiana, a Model for Plant Virology. Viruses 2022; 14:771. [PMID: 35458501 PMCID: PMC9027518 DOI: 10.3390/v14040771] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/04/2022] [Accepted: 04/04/2022] [Indexed: 02/01/2023] Open
Abstract
Nicotiana benthamiana is an indigenous plant species distributed across northern Australia. The laboratory accession (LAB) of N. benthamiana has become widely adopted as a model host for plant viruses, and it is distinct from other accessions morphologically, physiologically, and by having an attenuation-of-function mutation in the RNA-dependent RNA polymerase 1 (NbRdr1) gene, referred to as NbRdr1m. Recent historical evidence suggested LAB was derived from a 1936 collection by John Cleland at The Granites of the Northern Territory, although no scientific evidence was provided. We provide scientific evidence and further historical evidence supporting the origin of LAB as The Granites. Analysis of a herbarium specimen of N. benthamiana collected by Cleland in 1936 revealed that The Granites population contains plants heterozygous for the NbRdr1 locus, having both the functional NbRdr1 and the mutant NbRdr1m alleles. N. benthamiana was an important cultural asset actively utilised as the narcotic Pituri (chewing tobacco) by the Warlpiri Aboriginal people at the site, who prevented women of child-bearing age from consuming it. We propose that Aboriginal people selected some of the unique traits of LAB that have subsequently facilitated its adoption as a model plant, such as lack of seed dormancy, fast maturity, low nornicotine content, and gracility.
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Affiliation(s)
- Steve Wylie
- Plant Biotechnology Research Group (Virology), Western Australian State Agricultural Biotechnology Centre, Murdoch University, 90 South Street, Murdoch 6150, Australia;
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12
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Xu W, Guo Y, Li H, Sivasithamparam K, Jones MGK, Chen X, Wylie SJ. Differential Symptom Development and Viral RNA Loads in 10 Nicotiana benthamiana Accessions Infected with the Tobamovirus Yellow Tailflower Mild Mottle Virus. PLANT DISEASE 2022; 106:984-989. [PMID: 34735277 DOI: 10.1094/pdis-08-21-1697-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Yellow tailflower mild mottle virus (YTMMV, genus Tobamovirus) was identified from wild plants of solanaceous species in Australia. Nicotiana benthamiana is a species indigenous to the arid north of Australia. N. benthamiana accession RA-4 (the lab type), which has a mutant, functionally defective, RNA-dependent RNA polymerase 1 (Rdr1) gene (Nb-Rdr1m), has played a significant role in plant virology, but little study has been done regarding responses to virus infection by other accessions of N. benthamiana. All wild-collected N. benthamiana accessions used in this study harbored wild-type Rdr1 genes (Nb-Rdr1). We compared symptoms of YTMMV infection and viral RNA load on RA-4 and nine wild-collected accessions of N. benthamiana from mainland Western Australia, an island, and the Northern Territory. After inoculation with YTMMV, RA-4 plants responded with systemic hypersensitivity and all individuals were dead 35 days postinoculation (dpi). Plants of wild-collected accessions exhibited a range of symptoms, from mild to severe, and some, but not all, died in the same period. Quantitative reverse transcription PCR revealed that the Rdr1 mutation was not a predictor of viral RNA load or symptom severity. For example, wild-collected A019412 plants carried more than twice the viral RNA load of RA-4 plants, but symptom expression was moderate. For plants of most accessions, viral RNA load did not increase after 10 dpi. The exception was plants of accession Barrow-1, in which viral RNA load was low until 15 dpi, after which it increased more than 29-fold. This study revealed differential responses by N. benthamiana accessions to infection by an isolate of YTMMV. The Rdr1 gene, whether mutant or wild-type, did not appear to influence viral RNA load or disease expression. Genetic diversity of the 10 N. benthamiana accessions in some cases reflected geographical location, but in other accessions this was not so.
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Affiliation(s)
- Weinan Xu
- Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
- Plant Biotechnology Research Group (Virology), Western Australian State Agricultural Biotechnology Centre, Murdoch University, Murdoch 6150, Australia
- Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Yuxia Guo
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou 450002, China
| | - Hua Li
- Plant Biotechnology Research Group (Virology), Western Australian State Agricultural Biotechnology Centre, Murdoch University, Murdoch 6150, Australia
| | - Krishnapillai Sivasithamparam
- Plant Biotechnology Research Group (Virology), Western Australian State Agricultural Biotechnology Centre, Murdoch University, Murdoch 6150, Australia
| | - Michael G K Jones
- Plant Biotechnology Research Group (Virology), Western Australian State Agricultural Biotechnology Centre, Murdoch University, Murdoch 6150, Australia
| | - Xin Chen
- Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
- Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Stephen J Wylie
- Plant Biotechnology Research Group (Virology), Western Australian State Agricultural Biotechnology Centre, Murdoch University, Murdoch 6150, Australia
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13
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Liu Y, Zhang H. Reactive oxygen species and nitric oxide as mediators in plant hypersensitive response and stomatal closure. PLANT SIGNALING & BEHAVIOR 2021; 16:1985860. [PMID: 34668846 PMCID: PMC9208772 DOI: 10.1080/15592324.2021.1985860] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 05/31/2023]
Abstract
Nitric oxide (NO) and reactive oxygen species (ROS) have attracted considerable interest from plant pathologists since they regulate plant defenses via the hypersensitive response (HR) and stomatal closure. Here, we introduce the regulatory mechanisms of NO and ROS bursts and discuss the role of such bursts in HR and stomatal closure. It showed that epidermal sections of leaves respond to pathogens by the rapid and intense production of intracellular ROS and NO. Oxidative stress and H2O2 induce stomatal closure. Catalase and peroxidase-deficient plants are also hyperresponsive to pathogen invasion, suggesting a role for H2O2 in HR-mediated cell death. The analysis reveals that ROS and NO play important roles in stomatal closure and HR that involves multiple pathways. Therefore, multi-disciplinary and multi-omics combined analysis is crucial to the advancement of ROS and NO research and their role in plant defense mechanism.
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Affiliation(s)
- Yingjun Liu
- Department of Plant Pathology, College of Plant Protection, Anhui Agricultural University, Anhui Province Key Laboratory of Crop Integrated Pest Management, Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Hefei, Anhui, China
| | - Huajian Zhang
- Department of Plant Pathology, College of Plant Protection, Anhui Agricultural University, Anhui Province Key Laboratory of Crop Integrated Pest Management, Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Hefei, Anhui, China
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14
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Drapal M, Enfissi EMA, Fraser PD. Metabolic changes in leaves of N. tabacum and N. benthamiana during plant development. JOURNAL OF PLANT PHYSIOLOGY 2021; 265:153486. [PMID: 34388688 DOI: 10.1016/j.jplph.2021.153486] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 06/13/2023]
Abstract
Dwindling fossil fuel reserves and poor environmental credentials of chemical synthesis means, new renewable sources for the production and manufacture of valuable chemicals and pharmaceuticals are required. Presently, tobacco is an underutilised non-food crop with the potential to act as a biofactory. In this study, metabolite profiling across vegetative development has been carried out to provide a quantitative baseline of metabolites, their formation and interaction. Two tobacco platforms have been used, Nicotiana benthamiana and Nicotiana tabacum. Our data generated has provided the quantitative and qualitative baseline levels for exploitable pathways and metabolites, across two complementary Nicotiana species. N. benthamiana is the chassis of choice for transient expression. The metabolite data obtained for N. benthamiana highlighted that before flower emergence, the increased central carbon metabolism and high amino acid levels are available for the biosynthesis of endogenous or heterologous metabolites. In the future, engineering pathways or biocatalysts into N. benthamiana could add value to the process presently used to produce low volume, high cost pharmaceuticals. Similar outputs were obtained for N. tabacum, which has the advantage of providing a large biomass and hence, high product yield. These data provide an insight into the metabolite pools available in tobacco for future exploitation by emerging New Plant Breeding Techniques.
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Affiliation(s)
- Margit Drapal
- Department of Biological Sciences, Royal Holloway University of London, Egham, United Kingdom
| | - Eugenia M A Enfissi
- Department of Biological Sciences, Royal Holloway University of London, Egham, United Kingdom
| | - Paul D Fraser
- Department of Biological Sciences, Royal Holloway University of London, Egham, United Kingdom.
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15
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Lumata JL, Ball D, Shahrivarkevishahi A, Luzuriaga MA, Herbert FC, Brohlin O, Lee H, Hagge LM, D'Arcy S, Gassensmith JJ. Identification and physical characterization of a spontaneous mutation of the tobacco mosaic virus in the laboratory environment. Sci Rep 2021; 11:15109. [PMID: 34302022 PMCID: PMC8302582 DOI: 10.1038/s41598-021-94561-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 07/09/2021] [Indexed: 11/09/2022] Open
Abstract
Virus-like particles are an emerging class of nano-biotechnology with the Tobacco Mosaic Virus (TMV) having found a wide range of applications in imaging, drug delivery, and vaccine development. TMV is typically produced in planta, and, as an RNA virus, is highly susceptible to natural mutation that may impact its properties. Over the course of 2 years, from 2018 until 2020, our laboratory followed a spontaneous point mutation in the TMV coat protein-first observed as a 30 Da difference in electrospray ionization mass spectrometry (ESI-MS). The mutation would have been difficult to notice by electrophoretic mobility in agarose or SDS-PAGE and does not alter viral morphology as assessed by transmission electron microscopy. The mutation responsible for the 30 Da difference between the wild-type (wTMV) and mutant (mTMV) coat proteins was identified by a bottom-up proteomic approach as a change from glycine to serine at position 155 based on collision-induced dissociation data. Since residue 155 is located on the outer surface of the TMV rod, it is feasible that the mutation alters TMV surface chemistry. However, enzyme-linked immunosorbent assays found no difference in binding between mTMV and wTMV. Functionalization of a nearby residue, tyrosine 139, with diazonium salt, also appears unaffected. Overall, this study highlights the necessity of standard workflows to quality-control viral stocks. We suggest that ESI-MS is a straightforward and low-cost way to identify emerging mutants in coat proteins.
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Affiliation(s)
- Jenica L Lumata
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Darby Ball
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Arezoo Shahrivarkevishahi
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Michael A Luzuriaga
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Fabian C Herbert
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Olivia Brohlin
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Hamilton Lee
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Laurel M Hagge
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Sheena D'Arcy
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA. .,Department of Bioengineering, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA.
| | - Jeremiah J Gassensmith
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA. .,Department of Bioengineering, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA.
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16
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Drapal M, Enfissi EMA, Fraser PD. Metabolic effects of agro-infiltration on N. benthamiana accessions. Transgenic Res 2021; 30:303-315. [PMID: 33909228 PMCID: PMC8080481 DOI: 10.1007/s11248-021-00256-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 04/10/2021] [Indexed: 02/07/2023]
Abstract
Over the recent years, Nicotiana benthamiana has gained great importance as a chassis for the production of high value, low volume pharmaceuticals and/or active pharmaceutical ingredients (APIs). The process involving infiltration of the N. benthamiana leaves with Agrobacterium spp, harbouring vectors with the gene of interest, facilitates transient expression. To date, little information is available on the effect of the agro-infiltration process on the metabolome of N. benthamiana, which is necessary to improve the process for large-scale, renewable manufacturing of high value compounds and medical products. Hence, the objective of the present study was to assess metabolic adaptation of N. benthamiana as a response to the presence of Agrobacterium. The present study elucidated changes of the steady-state metabolism in the agroinfiltrated leaf area, the area around the infection and the rest of the plant. Furthermore, the study discusses the phenotypic advantages of the N. benthamiana lab strain, optimised for agro-infiltration, compared to three other wild accessions. Results showed that the lab strain has a different metabolic composition and showed less alterations of the phenylpropanoid pathway and cell wall remodelling in the agroinfiltrated leaf areas, for example chlorogenic acid, cadaverine and C18:0-2-glycerol ester. In conclusion, both of these alterations present potential candidates to improve the phenotype of the N. benthamiana lab strain for a more efficient transient expression process.
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Affiliation(s)
- Margit Drapal
- Biochemistry, Royal Holloway University of London, Egham, UK
| | | | - Paul D Fraser
- Biochemistry, Royal Holloway University of London, Egham, UK.
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17
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Enfissi EMA, Drapal M, Perez-Fons L, Nogueira M, Berry HM, Almeida J, Fraser PD. New plant breeding techniques and their regulatory implications: An opportunity to advance metabolomics approaches. JOURNAL OF PLANT PHYSIOLOGY 2021; 258-259:153378. [PMID: 33631493 DOI: 10.1016/j.jplph.2021.153378] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 01/31/2021] [Accepted: 02/01/2021] [Indexed: 05/21/2023]
Abstract
Over the previous decades, biotechnological innovations have led to improved agricultural productivity, more nutritious foods and lower chemical usage. Both in western societies and Low Medium Income Countries (LMICs). However, the projected increases in the global population, means the production of nutritious food stuffs must increase dramatically. Building on existing genetic modification technologies a series of New Plant Breeding Technologies (NPBT) has recently emerged. These approaches include, Agro-infiltration, grafting, cis and intragenesis and gene editing technologies. How these new techniques should be regulated has fostered considerable debate. Concerns have also been raised, to ensure over-regulation does not arise, creating administrative and economic burden. In this article the existing landscape of genetically modified crops is reviewed and the potential of several New Plant Breeding Techniques (NPBT) described. Metabolomics is an omic technology that has developed in a concurrent manner with biotechnological advances in plant breeding. There is potentially further opportunities to advance our metabolomic technologies to characterise the outputs of New Plant Breeding Technologies, in a manner that is beneficial both from an academic, biosafety and industrial perspective.
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Affiliation(s)
- Eugenia M A Enfissi
- Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham, TW20 0EX, United Kingdom
| | - Margit Drapal
- Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham, TW20 0EX, United Kingdom
| | - Laura Perez-Fons
- Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham, TW20 0EX, United Kingdom
| | - Marilise Nogueira
- Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham, TW20 0EX, United Kingdom
| | - Harriet M Berry
- Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham, TW20 0EX, United Kingdom
| | - Juliana Almeida
- Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham, TW20 0EX, United Kingdom
| | - Paul D Fraser
- Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham, TW20 0EX, United Kingdom.
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18
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Bačnik K, Kutnjak D, Pecman A, Mehle N, Tušek Žnidarič M, Gutiérrez Aguirre I, Ravnikar M. Viromics and infectivity analysis reveal the release of infective plant viruses from wastewater into the environment. WATER RESEARCH 2020; 177:115628. [PMID: 32299020 DOI: 10.1016/j.watres.2020.115628] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 02/13/2020] [Accepted: 02/14/2020] [Indexed: 05/06/2023]
Abstract
Viruses represent one of the most important threats to agriculture. Several viral families include highly stable pathogens, which remain infective and can be transported long distances in water. The diversity of plant viruses in wastewater remains understudied; however, their potential impact is increasing with the increased irrigation usage of reclaimed wastewater. To determine the abundance, diversity and biological relevance of plant viruses in wastewater influents and effluents we applied an optimized virus concentration method followed by high-throughput sequencing and infectivity assays. We detected representatives of 47 plant virus species, including emerging crop threats. We also demonstrated infectivity for pathogenic and economically relevant plant viruses from the genus Tobamovirus (family Virgaviridae), which remain infective even after conventional wastewater treatment. These results demonstrate the potential of metagenomics to capture the diversity of plant viruses circulating in the environment and expose the potential risk of the uncontrolled use of reclaimed water for irrigation.
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Affiliation(s)
- Katarina Bačnik
- National Institute of Biology, Department of Biotechnology and Systems Biology, Večna pot 111, 1000, Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova cesta 39, 1000, Ljubljana, Slovenia
| | - Denis Kutnjak
- National Institute of Biology, Department of Biotechnology and Systems Biology, Večna pot 111, 1000, Ljubljana, Slovenia
| | - Anja Pecman
- National Institute of Biology, Department of Biotechnology and Systems Biology, Večna pot 111, 1000, Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova cesta 39, 1000, Ljubljana, Slovenia
| | - Nataša Mehle
- National Institute of Biology, Department of Biotechnology and Systems Biology, Večna pot 111, 1000, Ljubljana, Slovenia
| | - Magda Tušek Žnidarič
- National Institute of Biology, Department of Biotechnology and Systems Biology, Večna pot 111, 1000, Ljubljana, Slovenia
| | - Ion Gutiérrez Aguirre
- National Institute of Biology, Department of Biotechnology and Systems Biology, Večna pot 111, 1000, Ljubljana, Slovenia
| | - Maja Ravnikar
- National Institute of Biology, Department of Biotechnology and Systems Biology, Večna pot 111, 1000, Ljubljana, Slovenia; University of Nova Gorica, Vipavska cesta, 5000, Nova Gorica, Slovenia.
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19
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Wu G, Hu Q, Du J, Li K, Sun M, Jing C, Li M, Li J, Qing L. Molecular characterization of virus-derived small RNAs in Nicotiana benthamiana plants infected with tobacco curly shoot virus and its β satellite. Virus Res 2019; 265:10-19. [PMID: 30831178 DOI: 10.1016/j.virusres.2019.02.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 02/25/2019] [Accepted: 02/28/2019] [Indexed: 10/27/2022]
Abstract
Tobacco curly shoot virus (TbCSV) is a monopartite DNA virus of the genus Begomovirus, which causes leaf curl symptoms in tobacco and tomato. The β satellite of TbCSV (TbCSB induces more severe symptoms and enhanced virus accumulation when co-infects the host plants with TbCSV. Small interfering RNAs derived from virus(vsiRNAs) induce disease symptoms and promote virus invasion by target and guide the degradation of host transcripts The vsiRNAs derived from TbCSV and TbCSV + TbCSB remained to be explored to elucidate the molecular mechanism of symptoms development in plants. In the present work, two libraries of small RNA from TbCSV-infected and TbCSV + TbCSB-infected N. benthamiana plants were constructed and the vsiRNAs in both samples shared the same characteristics. The size of the vsiRNAs ranged from 18 to 30 nucleotides (nt), with most of them being 21 or 22 nt, which accounted for 29.11% and 23.22% in TbCSV plants and 29.39% and 21.82% in TbCSV + TbCSV plants, respectively. The vsiRNAs with A/U bias at the first site were abundant in both the TbCSV-treated and TbCSV + TbCSB-treated plants. It is discovered that the vsiRNAs continuously, but heterogeneously, distributed through bothe the TbCSV and TbCSB sequences. And the distribution profiles were similar in both the treatments such as mainly in the overlapping region of the AC2/AC3 coding sequences. The host transcripts targeted by vsiRNAs were predicted, and the targeted genes were found to be involved in varied biological processes. It is indicated that the presence of TbCSB does not significantly affect the production of vsiRNAs from TbCSV in plants, the distribution hotsopt of TbCSV vsiRNAs could be useful in designing effective targets for TbCSV resistance exploiting RNA interference.
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Affiliation(s)
- Gentu Wu
- Chongqing Key Laboratory of Plant Disease Biology, College of Plant Protection, Southwest University, Chongqing, 400716, China.
| | - Qiao Hu
- Chongqing Key Laboratory of Plant Disease Biology, College of Plant Protection, Southwest University, Chongqing, 400716, China.
| | - Jiang Du
- Chongqing Key Laboratory of Plant Disease Biology, College of Plant Protection, Southwest University, Chongqing, 400716, China.
| | - Ke Li
- Chongqing Key Laboratory of Plant Disease Biology, College of Plant Protection, Southwest University, Chongqing, 400716, China.
| | - Miao Sun
- Chongqing Key Laboratory of Plant Disease Biology, College of Plant Protection, Southwest University, Chongqing, 400716, China.
| | - Chenchen Jing
- Chongqing Key Laboratory of Plant Disease Biology, College of Plant Protection, Southwest University, Chongqing, 400716, China.
| | - Mingjun Li
- Chongqing Key Laboratory of Plant Disease Biology, College of Plant Protection, Southwest University, Chongqing, 400716, China.
| | - Junmin Li
- Institute of Plant Virology, Ningbo University, Ningbo, 315211, China.
| | - Ling Qing
- Chongqing Key Laboratory of Plant Disease Biology, College of Plant Protection, Southwest University, Chongqing, 400716, China.
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Derevnina L, Kamoun S, Wu CH. Dude, where is my mutant? Nicotiana benthamiana meets forward genetics. THE NEW PHYTOLOGIST 2019; 221:607-610. [PMID: 30569612 DOI: 10.1111/nph.15521] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This article is a Commentary on Schultink et al., 221: 1001–1009.
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Affiliation(s)
- Lida Derevnina
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Sophien Kamoun
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Chih-Hang Wu
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UH, UK
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21
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Bally J, Jung H, Mortimer C, Naim F, Philips JG, Hellens R, Bombarely A, Goodin MM, Waterhouse PM. The Rise and Rise of Nicotiana benthamiana: A Plant for All Reasons. ANNUAL REVIEW OF PHYTOPATHOLOGY 2018; 56:405-426. [PMID: 30149789 DOI: 10.1146/annurev-phyto-080417-050141] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A decade ago, the value of Nicotiana benthamiana as a tool for plant molecular biologists was beginning to be appreciated. Scientists were using it to study plant-microbe and protein-protein interactions, and it was the species of choice with which to activate plasmid-encoded viruses, screen for gene functions with virus-induced gene silencing (VIGS), and transiently express genes by leaf agroinfiltration. However, little information about the species' origin, diversity, genetics, and genomics was available, and biologists were asking the question of whether N. benthamiana is a second fiddle or virtuoso. In this review, we look at the increased knowledge about the species and its applications over the past decade. Although N. benthamiana may still be the sidekick to Arabidopsis, it shines ever more brightly with realized and yet-to-be-exploited potential.
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Affiliation(s)
- Julia Bally
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, 4001 Brisbane, Queensland, Australia;
| | - Hyungtaek Jung
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, 4001 Brisbane, Queensland, Australia;
| | - Cara Mortimer
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, 4001 Brisbane, Queensland, Australia;
| | - Fatima Naim
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, 4001 Brisbane, Queensland, Australia;
| | - Joshua G Philips
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, 4001 Brisbane, Queensland, Australia;
| | - Roger Hellens
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, 4001 Brisbane, Queensland, Australia;
| | - Aureliano Bombarely
- Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0002, USA
| | - Michael M Goodin
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546, USA;
| | - Peter M Waterhouse
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, 4001 Brisbane, Queensland, Australia;
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22
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Dastogeer KMG, Li H, Sivasithamparam K, Jones MGK, Wylie SJ. Host Specificity of Endophytic Mycobiota of Wild Nicotiana Plants from Arid Regions of Northern Australia. MICROBIAL ECOLOGY 2018; 75:74-87. [PMID: 28702707 DOI: 10.1007/s00248-017-1020-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 06/15/2017] [Indexed: 06/07/2023]
Abstract
In arid regions of northern Australia, plants survive under water deficit, high temperatures, intense solar radiation and nutrient-impoverished soils. They employ various morpho-physiological and biochemical adaptations including interaction with microbial symbionts. We evaluated identity, host and tissue association with geographical distribution of fungal endophytes isolated from above- and below-ground tissues of plants of three indigenous Australian Nicotiana species. Isolation frequency and α-diversity were significantly higher for root endophyte assemblages than those of stem and leaf tissues. We recorded no differences in endophyte species richness or diversity as a function of sampling location, but did detect differences among different host genotypes and plant tissues. There was a significant pattern of community similarity associated with host genotypes but no consistent pattern of fungal community structuring associated with sampling location and tissue type, regardless of the community similarity measurements used.
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Affiliation(s)
- Khondoker M G Dastogeer
- Plant Biotechnology Group - Plant Virology, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, 6150, Australia
| | - Hua Li
- Plant Biotechnology Group - Plant Virology, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, 6150, Australia
| | - Krishnapillai Sivasithamparam
- Plant Biotechnology Group - Plant Virology, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, 6150, Australia
| | - Michael G K Jones
- Plant Biotechnology Group - Plant Virology, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, 6150, Australia
| | - Stephen J Wylie
- Plant Biotechnology Group - Plant Virology, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, 6150, Australia.
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Dastogeer KMG, Li H, Sivasithamparam K, Jones MGK, Wylie SJ. A simple and rapid in vitro test for large-scale screening of fungal endophytes from drought-adapted Australian wild plants for conferring water deprivation tolerance and growth promotion in Nicotiana benthamiana seedlings. Arch Microbiol 2017; 199:1357-1370. [PMID: 28733885 DOI: 10.1007/s00203-017-1411-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 06/13/2017] [Accepted: 07/14/2017] [Indexed: 10/19/2022]
Abstract
Some fungal endophytes confer novel phenotypes and enhance existing ones in plants, including tolerance to water deprivation stress. A range of fungal endophytes was isolated from wild Nicotiana plants growing in arid parts of northern Australia. These were screened for ability to enhance water deprivation stress tolerance by inoculating seedlings of the model plant N. benthamiana in two in vitro tests. Sixty-eight endophyte isolates were co-cultivated with N. benthamiana seedlings on either damp filter paper or on agar medium before being subjected to water deprivation. Seventeen isolates were selected for further testing under water deprivation conditions in a sand-based test in a glasshouse. Only two fungal isolates, Cladosporium cladosporioides (E-162) and an unknown fungus (E-284), significantly enhanced seedling tolerance to moisture deprivation consistently in both in vitro and sand-based tests. Although a strongly significant correlation was observed between any two screening methods, the result of filter paper test was more strongly reflected (r = 0.757, p < 0.001) in results of the glasshouse test, indicating its relative suitability over the agar-based test. In another experiment, the same 17 isolates carried forward to the sand-based test used in the glasshouse screening test were inoculated to N. benthamiana plants in pots in a nutrient-limiting environment to test their influence on growth promotion. Isolates related to C. cladosporioides, Fusarium equiseti, and Thozetella sp. promoted seedling growth by increasing shoot length and biomass. The fungal isolate E-162 (C. cladosporioides) significantly enhanced moisture deprivation tolerance as well as promoted seedling growth.
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Affiliation(s)
- Khondoker M G Dastogeer
- Plant Biotechnology Group, Plant Virology, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, WA, 6150, Australia
- Department of Plant Pathology, Bangladesh Agricultural University, Mymensingh, 2202, Bangladesh
| | - Hua Li
- Plant Biotechnology Group, Plant Virology, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, WA, 6150, Australia
| | - Krishnapillai Sivasithamparam
- Plant Biotechnology Group, Plant Virology, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, WA, 6150, Australia
| | - Michael G K Jones
- Plant Biotechnology Group, Plant Virology, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, WA, 6150, Australia
| | - Stephen J Wylie
- Plant Biotechnology Group, Plant Virology, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, WA, 6150, Australia.
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Goodin MM. Protein Localization and Interaction Studies in Plants: Toward Defining Complete Proteomes by Visualization. Adv Virus Res 2017; 100:117-144. [PMID: 29551133 DOI: 10.1016/bs.aivir.2017.10.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Protein interaction and localization studies in plants are a fundamental component of achieving mechanistic understanding of virus:plant interactions at the systems level. Many such studies are conducted using transient expression assays in leaves of Nicotiana benthamiana, the most widely used experimental plant host in virology, examined by laser-scanning confocal microscopy. This chapter provides a workflow for protein interaction and localization experiments, with particular attention to the many control and supporting assays that may also need to be performed. Basic principles of microscopy are introduced to aid researchers in the early stages of adding imaging techniques to their experimental repertoire. Three major types of imaging-based experiments are discussed in detail: (i) protein localization using autofluorescent proteins, (ii) colocalization studies, and (iii) bimolecular fluorescence complementation, with emphasis on judicious interpretation of the data obtained from these approaches. In addition to establishing a general framework for protein localization experiments in plants, the need for proteome-scale localization projects is discussed, with emphasis on nuclear-localized proteins.
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Nerva L, Varese GC, Falk BW, Turina M. Mycoviruses of an endophytic fungus can replicate in plant cells: evolutionary implications. Sci Rep 2017; 7:1908. [PMID: 28507331 PMCID: PMC5432518 DOI: 10.1038/s41598-017-02017-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 04/05/2017] [Indexed: 01/18/2023] Open
Abstract
So far there is no record of a specific virus able to infect both fungal and plant hosts in nature. However, experimental evidence shows that some plant virus RdRPs are able to perform replication in trans of genomic or DI RNAs in the yeast Saccharomyces cerevisiae. Furthermore, tobacco mosaic virus was recently shown to replicate in a filamentous ascomycetous fungus. Thus, at least experimentally, some plant viruses can infect some fungi. Endophytic fungi have been reported from many plants and several of these fungi have been shown to contain viruses. Here we tested if mycoviruses derived from a marine plant endophyte can replicate in plant cells. For this purpose, we used partially purified viral particles from isolate MUT4330 of Penicillium aurantiogriseum var. viridicatum which harbors six virus species, some having dsRNA and some positive-strand ssRNA genomes. These were transfected into three distinct plant protoplast cell systems. Time-course analysis of absolute RNA accumulation provided for the first time evidence that viruses of two species belonging to the Partitiviridae and Totiviridae families, can replicate in plant cells without evidence of host adaptation, i.e, changes in their nucleotide sequence.
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Affiliation(s)
- L Nerva
- Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135, Torino, Italy
- Mycotheca Universitatis Taurinensis (MUT), Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125, Torino, Italy
- Plant Pathology Department, University of California Davis, Davis, CA, 95616, USA
| | - G C Varese
- Mycotheca Universitatis Taurinensis (MUT), Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125, Torino, Italy
| | - B W Falk
- Plant Pathology Department, University of California Davis, Davis, CA, 95616, USA
| | - M Turina
- Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135, Torino, Italy.
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Koh SH, Li H, Sivasithamparam K, Admiraal R, Jones MGK, Wylie SJ. Evolution of a wild-plant tobamovirus passaged through an exotic host: Fixation of mutations and increased replication. Virus Evol 2017; 3:vex001. [PMID: 28458912 PMCID: PMC5399921 DOI: 10.1093/ve/vex001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Tobamovirus is a group of viruses that have become serious pathogens of crop plants. As part of a study informing risk of wild plant virus spill over to crops, we investigated the capacity of a solanaceous-infecting tobamovirus from an isolated indigenous flora to adapt to new exotic hosts. Yellow tailflower mild mottle virus (YTMMV) (genus Tobamovirus, family Virgaviridae) was isolated from a wild plant of yellow tailflower (Anthocercis littoria, family Solanaceae) and initially passaged through a plant of Nicotiana benthamiana, then one of Nicotiana glutinosa where a single local lesion was used to inoculate a N. benthamiana plant. Sap from this plant was used as starting material for nine serial passages through three plant species. The virus titre was recorded periodically, and 85% of the virus genome was sequenced at each passage for each host. Six polymorphic sites were found in the YTMMV genome across all hosts and passages. At five of these, the alternate alleles became fixed in the viral genome until the end of the experiment. Of these five alleles, one was a non-synonymous mutation (U1499C) that occurred only when the virus replicated in tomato. The mutant isolate harbouring U1499C, designated YTMMV-δ, increased its titre over passages in tomato and outcompeted the wild-type isolate when both were co-inoculated to tomato. That YTMMV-δ had greater reproductive fitness in an exotic host than did the wild type isolate suggests YTMMV evolution is influenced by host changes.
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Affiliation(s)
- Shu Hui Koh
- Plant Biotechnology Group - Plant Virology, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, WA 6150, Australia
| | - Hua Li
- Plant Biotechnology Group - Plant Virology, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, WA 6150, Australia
| | - Krishnapillai Sivasithamparam
- Plant Biotechnology Group - Plant Virology, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, WA 6150, Australia
| | - Ryan Admiraal
- School of Engineering and Information Technology, Mathematics & Statistics, Murdoch University, Perth, WA 6150, Australia
| | - Michael G K Jones
- Plant Biotechnology Group - Plant Virology, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, WA 6150, Australia
| | - Stephen J Wylie
- Plant Biotechnology Group - Plant Virology, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, WA 6150, Australia
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Deuschle K, Kepp G, Jeske H. Differential methylation of the circular DNA in geminiviral minichromosomes. Virology 2016; 499:243-258. [PMID: 27716464 DOI: 10.1016/j.virol.2016.09.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 09/22/2016] [Accepted: 09/24/2016] [Indexed: 10/20/2022]
Abstract
Geminiviral minichromosomes were purified to explore epigenetic modifications. The levels of methylation in their covalently closed circular DNA were examined with the help of methylation-dependent restriction (MdR). DNA with 12 superhelical turns was preferentially modified, indicating minichromosomes with 12 nucleosomes leaving an open gap. MdR digestion yielded a specific product of genomic length, which was cloned and Sanger-sequenced, or amplified following ligation-mediated rolling circle amplification and deep-sequenced (circomics). The conventional approach revealed a single cleavage product indicating specific methylations at the borders of the common region. The circomics approach identified considerably more MdR sites in a preferential distance to each other of ~200 nts, which is the DNA length in a nucleosome. They accumulated in regions of nucleosome-free gaps, but scattered also along the genomic components. These results may hint at a function in specific gene regulation, as well as in virus resistance.
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Affiliation(s)
- Kathrin Deuschle
- Institut für Biomaterialien und biomolekulare Systeme, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
| | - Gabi Kepp
- Institut für Biomaterialien und biomolekulare Systeme, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
| | - Holger Jeske
- Institut für Biomaterialien und biomolekulare Systeme, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
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A novel member of the Tombusviridae from a wild legume, Gompholobium preissii. Arch Virol 2016; 161:2893-8. [PMID: 27456427 DOI: 10.1007/s00705-016-2992-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 07/16/2016] [Indexed: 10/21/2022]
Abstract
As part of an investigation into viruses of wild plants in Australia, a contiguous sequence of 3935 nucleotides was obtained after shotgun sequencing of RNA isolated from an asymptomatic wild legume, Gompholobium preissii. Phylogenetic analysis of the sequence revealed that it most closely resembled that of Trailing lespedeza virus 1 (TLV1), a virus isolated from a wild legume in America. The proposed virus, named Gompholobium virus A, and TLV1 are genetically closest to viruses in the genera Alphacarmovirus and Pelarspovirus, family Tombusviridae, but they share features distinguishing them from both groups.
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RNA-dependent RNA polymerase 1 in potato (Solanum tuberosum) and its relationship to other plant RNA-dependent RNA polymerases. Sci Rep 2016; 6:23082. [PMID: 26979928 PMCID: PMC4793286 DOI: 10.1038/srep23082] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 02/22/2016] [Indexed: 02/07/2023] Open
Abstract
Cellular RNA-dependent RNA polymerases (RDRs) catalyze synthesis of double-stranded RNAs that can serve to initiate or amplify RNA silencing. Arabidopsis thaliana has six RDR genes; RDRs 1, 2 and 6 have roles in anti-viral RNA silencing. RDR6 is constitutively expressed but RDR1 expression is elevated following plant treatment with defensive phytohormones. RDR1 also contributes to basal virus resistance. RDR1 has been studied in several species including A. thaliana, tobacco (Nicotiana tabacum), N. benthamiana, N. attenuata and tomato (Solanum lycopersicum) but not to our knowledge in potato (S. tuberosum). StRDR1 was identified and shown to be salicylic acid-responsive. StRDR1 transcript accumulation decreased in transgenic potato plants constitutively expressing a hairpin construct and these plants were challenged with three viruses: potato virus Y, potato virus X, and tobacco mosaic virus. Suppression of StRDR1 gene expression did not increase the susceptibility of potato to these viruses. Phylogenetic analysis of RDR genes present in potato and in a range of other plant species identified a new RDR gene family, not present in potato and found only in Rosids (but apparently lost in the Rosid A. thaliana) for which we propose the name RDR7.
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Lee WS, Fu SF, Li Z, Murphy AM, Dobson EA, Garland L, Chaluvadi SR, Lewsey MG, Nelson RS, Carr JP. Salicylic acid treatment and expression of an RNA-dependent RNA polymerase 1 transgene inhibit lethal symptoms and meristem invasion during tobacco mosaic virus infection in Nicotiana benthamiana. BMC PLANT BIOLOGY 2016; 16:15. [PMID: 26757721 PMCID: PMC4710973 DOI: 10.1186/s12870-016-0705-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 01/06/2016] [Indexed: 05/23/2023]
Abstract
BACKGROUND Host RNA-dependent RNA polymerases (RDRs) 1 and 6 contribute to antiviral RNA silencing in plants. RDR6 is constitutively expressed and was previously shown to limit invasion of Nicotiana benthamiana meristem tissue by potato virus X and thereby inhibit disease development. RDR1 is inducible by salicylic acid (SA) and several other phytohormones. But although it contributes to basal resistance to tobacco mosaic virus (TMV) it is dispensable for SA-induced resistance in inoculated leaves. The laboratory accession of N. benthamiana is a natural rdr1 mutant and highly susceptible to TMV. However, TMV-induced symptoms are ameliorated in transgenic plants expressing Medicago truncatula RDR1. RESULTS In MtRDR1-transgenic N. benthamiana plants the spread of TMV expressing the green fluorescent protein (TMV.GFP) into upper, non-inoculated, leaves was not inhibited. However, in these plants exclusion of TMV.GFP from the apical meristem and adjacent stem tissue was greater than in control plants and this exclusion effect was enhanced by SA. TMV normally kills N. benthamiana plants but although MtRDR1-transgenic plants initially displayed virus-induced necrosis they subsequently recovered. Recovery from disease was markedly enhanced by SA treatment in MtRDR1-transgenic plants whereas in control plants SA delayed but did not prevent systemic necrosis and death. Following SA treatment of MtRDR1-transgenic plants, extractable RDR enzyme activity was increased and Western blot analysis of RDR extracts revealed a band cross-reacting with an antibody raised against MtRDR1. Expression of MtRDR1 in the transgenic N. benthamiana plants was driven by a constitutive 35S promoter derived from cauliflower mosaic virus, confirmed to be non-responsive to SA. This suggests that the effects of SA on MtRDR1 are exerted at a post-transcriptional level. CONCLUSIONS MtRDR1 inhibits severe symptom development by limiting spread of virus into the growing tips of infected plants. Thus, RDR1 may act in a similar fashion to RDR6. MtRDR1 and SA acted additively to further promote recovery from disease symptoms in MtRDR1-transgenic plants. Thus it is possible that SA promotes MtRDR1 activity and/or stability through post-transcriptional effects.
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Affiliation(s)
- Wing-Sham Lee
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK.
- Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.
| | - Shih-Feng Fu
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK.
- Department of Biology, National Changhua University of Education, 1 Jin-De Road, Changhua City, 500, Taiwan.
| | - Zheng Li
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK.
| | - Alex M Murphy
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK.
| | - Elizabeth A Dobson
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK.
| | - Laura Garland
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK.
| | - Srinivasa Rao Chaluvadi
- Plant Biology Division, Samuel Roberts Noble Foundation, Inc, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA.
| | - Mathew G Lewsey
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK.
- Centre for AgriBioscience, Department of Animal, Plant and Soil Science, School of Life Science, La Trobe University, Bundoora, Australia.
| | - Richard S Nelson
- Plant Biology Division, Samuel Roberts Noble Foundation, Inc, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA.
| | - John P Carr
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK.
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Todesco M, de Felippes FF. Why Benthamiana Went Viral. TRENDS IN PLANT SCIENCE 2016; 21:4-6. [PMID: 26698414 DOI: 10.1016/j.tplants.2015.11.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 11/27/2015] [Indexed: 06/05/2023]
Abstract
The broad susceptibility of Nicotiana benthamiana to viral infections has made it a prime model system for virology and molecular biology. A recent report suggests that this plant might actually have had a very good reason to shed its antiviral defences.
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Affiliation(s)
- Marco Todesco
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Felipe F de Felippes
- Department of Biology, Swiss Federal Institute of Technology (ETH-Z), 8092 Zurich, Switzerland
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