1
|
Collins ASP, Kurt H, Duggan C, Cotur Y, Coatsworth P, Naik A, Kaisti M, Bozkurt T, Güder F. Parallel, Continuous Monitoring and Quantification of Programmed Cell Death in Plant Tissue. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2400225. [PMID: 38531063 DOI: 10.1002/advs.202400225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 03/11/2024] [Indexed: 03/28/2024]
Abstract
Accurate quantification of hypersensitive response (HR) programmed cell death is imperative for understanding plant defense mechanisms and developing disease-resistant crop varieties. Here, a phenotyping platform for rapid, continuous-time, and quantitative assessment of HR is demonstrated: Parallel Automated Spectroscopy Tool for Electrolyte Leakage (PASTEL). Compared to traditional HR assays, PASTEL significantly improves temporal resolution and has high sensitivity, facilitating detection of microscopic levels of cell death. Validation is performed by transiently expressing the effector protein AVRblb2 in transgenic Nicotiana benthamiana (expressing the corresponding resistance protein Rpi-blb2) to reliably induce HR. Detection of cell death is achieved at microscopic intensities, where leaf tissue appears healthy to the naked eye one week after infiltration. PASTEL produces large amounts of frequency domain impedance data captured continuously. This data is used to develop supervised machine-learning (ML) models for classification of HR. Input data (inclusive of the entire tested concentration range) is classified as HR-positive or negative with 84.1% mean accuracy (F1 score = 0.75) at 1 h and with 87.8% mean accuracy (F1 score = 0.81) at 22 h. With PASTEL and the ML models produced in this work, it is possible to phenotype disease resistance in plants in hours instead of days to weeks.
Collapse
Affiliation(s)
| | - Hasan Kurt
- Department of Bioengineering, Royal School of Mines, Imperial College London, London, SW7 2AZ, UK
| | - Cian Duggan
- Department of Life Sciences, Royal School of Mines, Imperial College London, London, SW7 2AZ, UK
| | - Yasin Cotur
- Department of Bioengineering, Royal School of Mines, Imperial College London, London, SW7 2AZ, UK
| | - Philip Coatsworth
- Department of Bioengineering, Royal School of Mines, Imperial College London, London, SW7 2AZ, UK
| | - Atharv Naik
- Department of Bioengineering, Royal School of Mines, Imperial College London, London, SW7 2AZ, UK
| | - Matti Kaisti
- Department of Bioengineering, Royal School of Mines, Imperial College London, London, SW7 2AZ, UK
- Department of Computing, University of Turku, Vesilinnantie 5, Turku, 20500, Finland
| | - Tolga Bozkurt
- Department of Life Sciences, Royal School of Mines, Imperial College London, London, SW7 2AZ, UK
| | - Firat Güder
- Department of Bioengineering, Royal School of Mines, Imperial College London, London, SW7 2AZ, UK
| |
Collapse
|
2
|
Vermeulen A, Takken FLW, Sánchez-Camargo VA. Translation Arrest: A Key Player in Plant Antiviral Response. Genes (Basel) 2023; 14:1293. [PMID: 37372472 DOI: 10.3390/genes14061293] [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: 05/22/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023] Open
Abstract
Plants evolved several mechanisms to protect themselves against viruses. Besides recessive resistance, where compatible host factors required for viral proliferation are absent or incompatible, there are (at least) two types of inducible antiviral immunity: RNA silencing (RNAi) and immune responses mounted upon activation of nucleotide-binding domain leucine-rich repeat (NLR) receptors. RNAi is associated with viral symptom recovery through translational repression and transcript degradation following recognition of viral double-stranded RNA produced during infection. NLR-mediated immunity is induced upon (in)direct recognition of a viral protein by an NLR receptor, triggering either a hypersensitive response (HR) or an extreme resistance response (ER). During ER, host cell death is not apparent, and it has been proposed that this resistance is mediated by a translational arrest (TA) of viral transcripts. Recent research indicates that translational repression plays a crucial role in plant antiviral resistance. This paper reviews current knowledge on viral translational repression during viral recovery and NLR-mediated immunity. Our findings are summarized in a model detailing the pathways and processes leading to translational arrest of plant viruses. This model can serve as a framework to formulate hypotheses on how TA halts viral replication, inspiring new leads for the development of antiviral resistance in crops.
Collapse
Affiliation(s)
- Annemarie Vermeulen
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Frank L W Takken
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Victor A Sánchez-Camargo
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| |
Collapse
|
3
|
Király L, Albert R, Zsemberi O, Schwarczinger I, Hafez YM, Künstler A. Reactive Oxygen Species Contribute to Symptomless, Extreme Resistance to Potato virus X in Tobacco. PHYTOPATHOLOGY 2021; 111:1870-1884. [PMID: 33593113 DOI: 10.1094/phyto-12-20-0540-r] [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] [Indexed: 06/12/2023]
Abstract
Here we show that in tobacco (Nicotiana tabacum cultivar Samsun NN Rx1) the development of Rx1 gene-mediated, symptomless, extreme resistance to Potato virus X (PVX) is preceded by an early, intensive accumulation of the reactive oxygen species (ROS) superoxide (O2·-), evident between 1 and 6 h after inoculation and associated with increased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activities. This suggests a direct contribution of this ROS to virus restriction during symptomless, extreme resistance. Superoxide inhibition in PVX-inoculated leaves by infiltration of antioxidants (superoxide dismutase [SOD] and catalase [CAT]) partially suppresses extreme resistance in parallel with the appearance of localized leaf necrosis resembling a hypersensitive resistance (HR) response. F1 progeny from crosses of Rx1 and ferritin overproducer (deficient in production of the ROS OH·) tobaccos also display a suppressed extreme resistance to PVX, because significantly increased virus levels are coupled to HR, suggesting a role of the hydroxyl radical (OH·) in this symptomless antiviral defense. In addition, treatment of PVX-susceptible tobacco with a superoxide-generating agent (riboflavin/methionine) results in HR-like symptoms and reduced PVX titers. Finally, by comparing defense responses during PVX-elicited symptomless, extreme resistance and HR-type resistance elicited by Tobacco mosaic virus, we conclude that defense reactions typical of an HR (e.g., induction of cell death/ROS-regulator genes and antioxidants) are early and transient in the course of extreme resistance. Our results demonstrate the contribution of early accumulation of ROS (superoxide, OH·) in limiting PVX replication during symptomless extreme resistance and support earlier findings that virus-elicited HR represents a delayed, slower resistance response than symptomless, extreme resistance.
Collapse
Affiliation(s)
- Lóránt Király
- Department of Plant Pathophysiology, Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network (ELKH), H-1022 Budapest, Hungary
| | - Réka Albert
- Department of Plant Pathophysiology, Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network (ELKH), H-1022 Budapest, Hungary
| | - Orsolya Zsemberi
- Division of Toxicology, Wageningen University & Research, 6708 WE Wageningen, The Netherlands
| | - Ildikó Schwarczinger
- Department of Plant Pathophysiology, Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network (ELKH), H-1022 Budapest, Hungary
| | - Yaser Mohamed Hafez
- EPCRS Excellence Center & Plant Pathology and Biotechnology Lab, Department of Agricultural Botany, Faculty of Agriculture, Kafrelsheikh University, 33516 Kafr-El-Sheikh, Egypt
| | - András Künstler
- Department of Plant Pathophysiology, Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network (ELKH), H-1022 Budapest, Hungary
| |
Collapse
|
4
|
Ross BT, Zidack NK, Flenniken ML. Extreme Resistance to Viruses in Potato and Soybean. FRONTIERS IN PLANT SCIENCE 2021; 12:658981. [PMID: 33889169 PMCID: PMC8056081 DOI: 10.3389/fpls.2021.658981] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/12/2021] [Indexed: 05/31/2023]
Abstract
Plant pathogens, including viruses, negatively impact global crop production. Plants have evolved complex immune responses to pathogens. These responses are often controlled by nucleotide-binding leucine-rich repeat proteins (NLRs), which recognize intracellular, pathogen-derived proteins. Genetic resistance to plant viruses is often phenotypically characterized by programmed cell death at or near the infection site; a reaction termed the hypersensitive response. Although visualization of the hypersensitive response is often used as a hallmark of resistance, the molecular mechanisms leading to the hypersensitive response and associated cell death vary. Plants with extreme resistance to viruses rarely exhibit symptoms and have little to no detectable virus replication or spread beyond the infection site. Both extreme resistance and the hypersensitive response can be activated by the same NLR genes. In many cases, genes that normally provide an extreme resistance phenotype can be stimulated to cause a hypersensitive response by experimentally increasing cellular levels of pathogen-derived elicitor protein(s). The molecular mechanisms of extreme resistance and its relationship to the hypersensitive response are largely uncharacterized. Studies on potato and soybean cultivars that are resistant to strains of Potato virus Y (PVY), Potato virus X (PVX), and Soybean mosaic virus (SMV) indicate that abscisic acid (ABA)-mediated signaling and NLR nuclear translocation are important for the extreme resistance response. Recent research also indicates that some of the same proteins are involved in both extreme resistance and the hypersensitive response. Herein, we review and synthesize published studies on extreme resistance in potato and soybean, and describe studies in additional species, including model plant species, to highlight future research avenues that may bridge the gaps in our knowledge of plant antiviral defense mechanisms.
Collapse
Affiliation(s)
- Brian T. Ross
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, United States
| | - Nina K. Zidack
- Montana State Seed Potato Certification Lab, Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, United States
| | - Michelle L. Flenniken
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, United States
- Montana State Seed Potato Certification Lab, Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, United States
| |
Collapse
|
5
|
Richard MMS, Knip M, Schachtschabel J, Beijaert MS, Takken FLW. Perturbation of nuclear-cytosolic shuttling of Rx1 compromises extreme resistance and translational arrest of potato virus X transcripts. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:468-479. [PMID: 33524169 PMCID: PMC8252585 DOI: 10.1111/tpj.15179] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 01/24/2021] [Accepted: 01/26/2021] [Indexed: 06/01/2023]
Abstract
Many plant intracellular immune receptors mount a hypersensitive response (HR) upon pathogen perception. The concomitant localized cell death is proposed to trap pathogens, such as viruses, inside infected cells, thereby preventing their spread. Notably, extreme resistance (ER) conferred by the potato immune receptor Rx1 to potato virus X (PVX) does not involve the death of infected cells. It is unknown what defines ER and how it differs from HR-based resistance. Interestingly, Rx1 can trigger an HR, but only upon artificial (over)expression of PVX or its avirulence coat protein (CP). Rx1 has a nucleocytoplasmic distribution and both pools are required for HR upon transient expression of a PVX-GFP amplicon. It is unknown whether mislocalized Rx1 variants can induce ER upon natural PVX infection. Here, we generated transgenic Nicotiana benthamiana producing nuclear- or cytosol-restricted Rx1 variants. We found that these variants can still mount an HR. However, nuclear- or cytosol-restricted Rx1 variants can no longer trigger ER or restricts viral infection. Interestingly, unlike the mislocalized Rx1 variants, wild-type Rx1 was found to compromise CP protein accumulation. We show that the lack of CP accumulation does not result from its degradation but is likely to be linked with translational arrest of its mRNA. Together, our findings suggest that translational arrest of viral genes is a major component of ER and, unlike the HR, is required for resistance to PVX.
Collapse
Affiliation(s)
- Manon M. S. Richard
- Molecular Plant PathologySwammerdam Institute for Life Sciences (SILS)University of AmsterdamAmsterdamthe Netherlands
| | - Marijn Knip
- Molecular Plant PathologySwammerdam Institute for Life Sciences (SILS)University of AmsterdamAmsterdamthe Netherlands
| | - Joëlle Schachtschabel
- Molecular Plant PathologySwammerdam Institute for Life Sciences (SILS)University of AmsterdamAmsterdamthe Netherlands
| | - Machiel S. Beijaert
- Molecular Plant PathologySwammerdam Institute for Life Sciences (SILS)University of AmsterdamAmsterdamthe Netherlands
| | - Frank L. W. Takken
- Molecular Plant PathologySwammerdam Institute for Life Sciences (SILS)University of AmsterdamAmsterdamthe Netherlands
| |
Collapse
|
6
|
Wang J, Han M, Liu Y. Diversity, structure and function of the coiled-coil domains of plant NLR immune receptors. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:283-296. [PMID: 33205883 DOI: 10.1111/jipb.13032] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Accepted: 11/03/2020] [Indexed: 06/11/2023]
Abstract
Plant nucleotide-binding, leucine-rich repeat receptors (NLRs) perceive pathogen avirulence effectors and activate defense responses. Nucleotide-binding, leucine-rich repeat receptors are classified into coiled-coil (CC)-containing and Toll/interleukin-1 receptor (TIR)-containing NLRs. Recent advances suggest that NLR CC domains often function in signaling activation, especially for induction of cell death. In this review, we outline our current understanding of NLR CC domains, including their diversity/classification and structure, their roles in cell death induction, disease resistance, and interaction with other proteins. Furthermore, we provide possible directions for future work.
Collapse
Affiliation(s)
- Junzhu Wang
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Meng Han
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Yule Liu
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| |
Collapse
|
7
|
Genomic dissection of ROS detoxifying enzyme encoding genes for their role in antioxidative defense mechanism against Tomato leaf curl New Delhi virus infection in tomato. Genomics 2021; 113:889-899. [PMID: 33524498 DOI: 10.1016/j.ygeno.2021.01.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 01/13/2021] [Accepted: 01/27/2021] [Indexed: 01/23/2023]
Abstract
In the present study, genes encoding for six major classes of enzymatic antioxidants, namely superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), Peroxidase (Prx) and glutathione S-transferase (GST) are identified in tomato. Their expression was studied in tomato cultivars contrastingly tolerant to ToLCNDV during virus infection and different hormone treatments. Significant upregulation of SlGR3, SlPrx25, SlPrx75, SlPrx95, SlGST44, and SlGST96 was observed in the tolerant cultivar during disease infection. Virus-induced gene silencing of SlGR3 in the tolerant cultivar conferred disease susceptibility to the knock-down line, and higher accumulation (~80%) of viral DNA was observed in the tolerant cultivar. Further, subcellular localization of SlGR3 showed its presence in cytoplasm, and its enzymatic activity was found to be increased (~65%) during ToLCNDV infection. Knock-down lines showed ~3- and 3.5-fold reduction in GR activity, which altogether underlines that SlGR3 is vital component of the defense mechanism against ToLCNDV infection.
Collapse
|
8
|
Toum L, Conti G, Guerriero FC, Conforte VP, Garolla FA, Asurmendi S, Vojnov AA, Gudesblat GE. Single-stranded oligodeoxynucleotides induce plant defence in Arabidopsis thaliana. ANNALS OF BOTANY 2020; 126:413-422. [PMID: 32266377 PMCID: PMC7424753 DOI: 10.1093/aob/mcaa061] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 04/06/2020] [Indexed: 05/12/2023]
Abstract
BACKGROUND AND AIMS Single-stranded DNA oligodeoxynucleotides (ssODNs) have been shown to elicit immune responses in mammals. In plants, RNA and genomic DNA can activate immunity, although the exact mechanism through which they are sensed is not clear. The aim of this work was to study the possible effect of ssODNs on plant immunity. KEY RESULTS The ssODNs IMT504 and 2006 increased protection against the pathogens Pseudomonas syringae pv. tomato DC3000 and Botrytis cinerea but not against tobacco mosaic virus-Cg when infiltrated in Arabidopsis thaliana. In addition, ssODNs inhibited root growth and promoted stomatal closure in a concentration-dependent manner, with half-maximal effective concentrations between 0.79 and 2.06 µm. Promotion of stomatal closure by ssODNs was reduced by DNase I treatment. It was also diminished by the NADPH oxidase inhibitor diphenyleneiodonium and by coronatine, a bacterial toxin that inhibits NADPH oxidase-dependent reactive oxygen species (ROS) synthesis in guard cells. In addition it was found that ssODN-mediated stomatal closure was impaired in bak1-5, bak1-5/bkk1, mpk3 and npr1-3 mutants. ssODNs also induced early expression of MPK3, WRKY33, PROPEP1 and FRK1 genes involved in plant defence, an effect that was reduced in bak1-5 and bak1-5/bkk1 mutants. CONCLUSIONS ssODNs are capable of inducing protection against pathogens through the activation of defence genes and promotion of stomatal closure through a mechanism similar to that of other elicitors of plant immunity, which involves the BAK1 co-receptor, and ROS synthesis.
Collapse
Affiliation(s)
- Laila Toum
- Instituto de Ciencia y Tecnología Dr. César Milstein, Fundación Pablo Cassará, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Saladillo, Argentina
| | - Gabriela Conti
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), CICVyA – Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Los Reseros y Nicolas Repeto, Hurlingham, Argentina
| | - Francesca Coppola Guerriero
- Departamento de Fisiología, Biología Molecular y Celular ‘Profesor Héctor Maldonado’ – Instituto de Biociencias, Biotecnología y Biología Translacional (IB3), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pres. Dr. Raúl Alfonsín S/N, Ciudad Universitaria, Argentina
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pres. Dr. Raúl Alfonsín S/N, Ciudad Universitaria, Argentina
- Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), CONICET, Argentina
| | - Valeria P Conforte
- Instituto de Ciencia y Tecnología Dr. César Milstein, Fundación Pablo Cassará, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Saladillo, Argentina
| | - Franco A Garolla
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pres. Dr. Raúl Alfonsín S/N, Ciudad Universitaria, Argentina
| | - Sebastián Asurmendi
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), CICVyA – Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Los Reseros y Nicolas Repeto, Hurlingham, Argentina
| | - Adrián A Vojnov
- Instituto de Ciencia y Tecnología Dr. César Milstein, Fundación Pablo Cassará, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Saladillo, Argentina
| | - Gustavo E Gudesblat
- Departamento de Fisiología, Biología Molecular y Celular ‘Profesor Héctor Maldonado’ – Instituto de Biociencias, Biotecnología y Biología Translacional (IB3), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pres. Dr. Raúl Alfonsín S/N, Ciudad Universitaria, Argentina
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pres. Dr. Raúl Alfonsín S/N, Ciudad Universitaria, Argentina
- Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), CONICET, Argentina
- For correspondence. E-mail:
| |
Collapse
|
9
|
Richard MMS, Knip M, Aalders T, Beijaert MS, Takken FLW. Unlike Many Disease Resistances, Rx1-Mediated Immunity to Potato Virus X Is Not Compromised at Elevated Temperatures. Front Genet 2020; 11:417. [PMID: 32391063 PMCID: PMC7193704 DOI: 10.3389/fgene.2020.00417] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 04/02/2020] [Indexed: 12/22/2022] Open
Abstract
Specificity in the plant immune system is mediated by Resistance (R) proteins. Most R genes encode intracellular NLR-type immune receptors and these pathogen sensors require helper NLRs to activate immune signaling upon pathogen perception. Resistance conferred by many R genes is temperature sensitive and compromised above 28°C. Many Solanaceae R genes, including the potato NLR Rx1 conferring resistance to Potato Virus X (PVX), have been reported to be temperature labile. Rx1 activity, like many Solanaceae NLRs, depends on helper-NLRs called NRC's. In this study, we investigated Rx1 resistance at elevated temperatures in potato and in Nicotiana benthamiana plants stably expressing Rx1 upon rub-inoculation with GFP-expressing PVX particles. In parallel, we used susceptible plants as a control to assess infectiousness of PVX at a range of different temperatures. Surprisingly, we found that Rx1 confers virus resistance in N. benthamiana up to 32°C, a temperature at which the PVX::GFP lost infectiousness. Furthermore, at 34°C, an Rx1-mediated hypersensitive response could still be triggered in N. benthamiana upon PVX Coat-Protein overexpression. As the Rx1-immune signaling pathway is not temperature compromised, this implies that at least one N. benthamiana helper NRC and its downstream signaling components are temperature tolerant. This finding suggests that the temperature sensitivity for Solanaceous resistances is likely attributable to the sensor NLR and not to its downstream signaling components.
Collapse
Affiliation(s)
- Manon M S Richard
- Swammerdam Institute for Life Sciences (SILS), Molecular Plant Pathology, University of Amsterdam, Amsterdam, Netherlands
| | - Marijn Knip
- Swammerdam Institute for Life Sciences (SILS), Molecular Plant Pathology, University of Amsterdam, Amsterdam, Netherlands
| | - Thomas Aalders
- Swammerdam Institute for Life Sciences (SILS), Molecular Plant Pathology, University of Amsterdam, Amsterdam, Netherlands
| | - Machiel S Beijaert
- Swammerdam Institute for Life Sciences (SILS), Molecular Plant Pathology, University of Amsterdam, Amsterdam, Netherlands
| | - Frank L W Takken
- Swammerdam Institute for Life Sciences (SILS), Molecular Plant Pathology, University of Amsterdam, Amsterdam, Netherlands
| |
Collapse
|