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Rocher F, Alouane T, Philippe G, Martin ML, Label P, Langin T, Bonhomme L. Fusarium graminearum Infection Strategy in Wheat Involves a Highly Conserved Genetic Program That Controls the Expression of a Core Effectome. Int J Mol Sci 2022; 23:ijms23031914. [PMID: 35163834 PMCID: PMC8836836 DOI: 10.3390/ijms23031914] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/03/2022] [Accepted: 02/04/2022] [Indexed: 12/13/2022] Open
Abstract
Fusarium graminearum, the main causal agent of Fusarium Head Blight (FHB), is one of the most damaging pathogens in wheat. Because of the complex organization of wheat resistance to FHB, this pathosystem represents a relevant model to elucidate the molecular mechanisms underlying plant susceptibility and to identify their main drivers, the pathogen’s effectors. Although the F. graminearum catalog of effectors has been well characterized at the genome scale, in planta studies are needed to confirm their effective accumulation in host tissues and to identify their role during the infection process. Taking advantage of the genetic variability from both species, a RNAseq-based profiling of gene expression was performed during an infection time course using an aggressive F. graminearum strain facing five wheat cultivars of contrasting susceptibility as well as using three strains of contrasting aggressiveness infecting a single susceptible host. Genes coding for secreted proteins and exhibiting significant expression changes along infection progress were selected to identify the effector gene candidates. During its interaction with the five wheat cultivars, 476 effector genes were expressed by the aggressive strain, among which 91% were found in all the infected hosts. Considering three different strains infecting a single susceptible host, 761 effector genes were identified, among which 90% were systematically expressed in the three strains. We revealed a robust F. graminearum core effectome of 357 genes expressed in all the hosts and by all the strains that exhibited conserved expression patterns over time. Several wheat compartments were predicted to be targeted by these putative effectors including apoplast, nucleus, chloroplast and mitochondria. Taken together, our results shed light on a highly conserved parasite strategy. They led to the identification of reliable key fungal genes putatively involved in wheat susceptibility to F. graminearum, and provided valuable information about their putative targets.
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Affiliation(s)
- Florian Rocher
- UMR 1095 Génétique Diversité Ecophysiologie des Céréales, INRAE, Université Clermont Auvergne, 63000 Clermont-Ferrand, France; (F.R.); (T.A.); (G.P.); (T.L.)
| | - Tarek Alouane
- UMR 1095 Génétique Diversité Ecophysiologie des Céréales, INRAE, Université Clermont Auvergne, 63000 Clermont-Ferrand, France; (F.R.); (T.A.); (G.P.); (T.L.)
| | - Géraldine Philippe
- UMR 1095 Génétique Diversité Ecophysiologie des Céréales, INRAE, Université Clermont Auvergne, 63000 Clermont-Ferrand, France; (F.R.); (T.A.); (G.P.); (T.L.)
| | - Marie-Laure Martin
- Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, INRAE, Université Paris-Saclay, Université Evry, 91190 Gif sur Yvette, France;
- Institute of Plant Sciences Paris-Saclay (IPS2), Université de Paris, 91190 Gif sur Yvette, France
- UMR MIA-Paris, AgroParisTech, INRA, Université Paris-Saclay, 75005 Paris, France
| | - Philippe Label
- UMR 547 Physique et Physiologie Intégratives de l’Arbre en environnement Fluctuant, INRAE, Université Clermont Auvergne, 63178 Aubière, France;
| | - Thierry Langin
- UMR 1095 Génétique Diversité Ecophysiologie des Céréales, INRAE, Université Clermont Auvergne, 63000 Clermont-Ferrand, France; (F.R.); (T.A.); (G.P.); (T.L.)
| | - Ludovic Bonhomme
- UMR 1095 Génétique Diversité Ecophysiologie des Céréales, INRAE, Université Clermont Auvergne, 63000 Clermont-Ferrand, France; (F.R.); (T.A.); (G.P.); (T.L.)
- Correspondence:
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2
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Savage Z, Duggan C, Toufexi A, Pandey P, Liang Y, Segretin ME, Yuen LH, Gaboriau DCA, Leary AY, Tumtas Y, Khandare V, Ward AD, Botchway SW, Bateman BC, Pan I, Schattat M, Sparkes I, Bozkurt TO. Chloroplasts alter their morphology and accumulate at the pathogen interface during infection by Phytophthora infestans. Plant J 2021; 107:1771-1787. [PMID: 34250673 DOI: 10.1111/tpj.15416] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/02/2021] [Accepted: 07/08/2021] [Indexed: 05/22/2023]
Abstract
Upon immune activation, chloroplasts switch off photosynthesis, produce antimicrobial compounds and associate with the nucleus through tubular extensions called stromules. Although it is well established that chloroplasts alter their position in response to light, little is known about the dynamics of chloroplast movement in response to pathogen attack. Here, we report that during infection with the Irish potato famine pathogen Phytophthora infestans, chloroplasts accumulate at the pathogen interface, associating with the specialized membrane that engulfs the pathogen haustorium. The chemical inhibition of actin polymerization reduces the accumulation of chloroplasts at pathogen haustoria, suggesting that this process is partially dependent on the actin cytoskeleton. However, chloroplast accumulation at haustoria does not necessarily rely on movement of the nucleus to this interface and is not affected by light conditions. Stromules are typically induced during infection, embracing haustoria and facilitating chloroplast interactions, to form dynamic organelle clusters. We found that infection-triggered stromule formation relies on BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED KINASE 1 (BAK1)-mediated surface immune signaling, whereas chloroplast repositioning towards haustoria does not. Consistent with the defense-related induction of stromules, effector-mediated suppression of BAK1-mediated immune signaling reduced stromule formation during infection. On the other hand, immune recognition of the same effector stimulated stromules, presumably via a different pathway. These findings implicate chloroplasts in a polarized response upon pathogen attack and point to more complex functions of these organelles in plant-pathogen interactions.
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Affiliation(s)
- Zachary Savage
- Department of Life Sciences, Imperial College London, Imperial College Road, South Kensington Campus, London, London, SW7 2AZ, UK
| | - Cian Duggan
- Department of Life Sciences, Imperial College London, Imperial College Road, South Kensington Campus, London, London, SW7 2AZ, UK
| | - Alexia Toufexi
- Department of Life Sciences, Imperial College London, Imperial College Road, South Kensington Campus, London, London, SW7 2AZ, UK
| | - Pooja Pandey
- Department of Life Sciences, Imperial College London, Imperial College Road, South Kensington Campus, London, London, SW7 2AZ, UK
| | - Yuxi Liang
- Department of Life Sciences, Imperial College London, Imperial College Road, South Kensington Campus, London, London, SW7 2AZ, UK
| | - María Eugenia Segretin
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular 'Dr Héctor N. Torres' (INGEBI)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Vuelta de Obligado 2490, Ciudad Autónoma de Buenos Aires, C1428ADN, Argentina
| | - Lok Him Yuen
- Department of Life Sciences, Imperial College London, Imperial College Road, South Kensington Campus, London, London, SW7 2AZ, UK
| | - David C A Gaboriau
- Facility for Imaging by Light Microscopy, Faculty of Medicine, National Heart & Lung Institute (NHLI), Imperial College London, South Kensington, SAF building, London, SW7 2AZ, UK
| | - Alexandre Y Leary
- Department of Life Sciences, Imperial College London, Imperial College Road, South Kensington Campus, London, London, SW7 2AZ, UK
| | - Yasin Tumtas
- Department of Life Sciences, Imperial College London, Imperial College Road, South Kensington Campus, London, London, SW7 2AZ, UK
| | - Virendrasinh Khandare
- Department of Life Sciences, Imperial College London, Imperial College Road, South Kensington Campus, London, London, SW7 2AZ, UK
| | - Andrew D Ward
- Central Laser Facility, Science and Technology Facilities Council Harwell, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, Didcot, OX11 0QX, UK
| | - Stanley W Botchway
- Central Laser Facility, Science and Technology Facilities Council Harwell, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, Didcot, OX11 0QX, UK
| | - Benji C Bateman
- Central Laser Facility, Science and Technology Facilities Council Harwell, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, Didcot, OX11 0QX, UK
| | - Indranil Pan
- Centre for Process Systems Engineering and Centre for Environmental Policy, Imperial College London, South Kensington Campus, London, London, SW7 2AZ, UK
- The Alan Turing Institute, British Library, 96 Euston Road, London, London, NW1 2DB, UK
| | - Martin Schattat
- Martin Luther Universität Halle-Wittenberg, Halle, 06108 Halle, Germany
| | - Imogen Sparkes
- School of Biological Sciences, University of Bristol, University of Bristol, St Michael's Hill, Bristol, BS8 8DZ, UK
| | - Tolga O Bozkurt
- Department of Life Sciences, Imperial College London, Imperial College Road, South Kensington Campus, London, London, SW7 2AZ, UK
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Tzelepis G, Dölfors F, Holmquist L, Dixelius C. Plant mitochondria and chloroplasts are targeted by the Rhizoctonia solani RsCRP1 effector. Biochem Biophys Res Commun 2021; 544:86-90. [PMID: 33550013 DOI: 10.1016/j.bbrc.2021.01.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 01/07/2021] [Indexed: 01/10/2023]
Abstract
The fungal species Rhizoctonia solani belongs to the Basidiomycota division and is a ubiquitous soil-borne pathogen. It is the main agent of the damping-off disease in seedlings and causes the root and crown rot disease in sugar beets. Plant pathogens deploy small secreted proteins, called effectors, to manipulate plant immunity in order to infect the host. Here, a gene (RsCRP1) encoded a putative effector cysteine-rich protein was cloned, expressed in Cercospora beticola and used for virulence assays. The RsCRP1 gene was highly induced upon the early-infection stage of sugar beet seedlings and disease was promoted. Confocal microscopy demonstrated localization to the chloroplasts and mitochondria upon transient expression of RsCRP1 in leaves of Nicotiana benthamiana. Further, this effector was unable to induce necrosis or to suppress hypersensitive response induced by the Avr4/Cf4 complex in N. benthamiana. Overall, these data indicate that RsCRP1 is a novel effector targeting distinct plant cell organelles in order to facilitate a successful infection at the early stages of the disease development.
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Affiliation(s)
- Georgios Tzelepis
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala Biocenter, Box 7026, SE-750 07, Uppsala, Sweden.
| | - Fredrik Dölfors
- Swedish University of Agricultural Sciences, Department of Plant Biology, Uppsala BioCenter, Linnean Center for Plant Biology, P.O. Box 7080, S-75007, Uppsala, Sweden
| | - Louise Holmquist
- MariboHilleshög Research AB, Säbyholmsvägen 24, S-26191, Landskrona, Sweden
| | - Christina Dixelius
- Swedish University of Agricultural Sciences, Department of Plant Biology, Uppsala BioCenter, Linnean Center for Plant Biology, P.O. Box 7080, S-75007, Uppsala, Sweden
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Kopczewski T, Kuźniak E, Kornaś A, Rut G, Nosek M, Ciereszko I, Szczepaniak L. Local and Systemic Changes in Photosynthetic Parameters and Antioxidant Activity in Cucumber Challenged with Pseudomonas syringae pv lachrymans. Int J Mol Sci 2020; 21:E6378. [PMID: 32887449 PMCID: PMC7504232 DOI: 10.3390/ijms21176378] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/30/2020] [Accepted: 08/31/2020] [Indexed: 12/20/2022] Open
Abstract
We studied changes in gas exchange, photochemical activity and the antioxidant system in cucumber leaves locally infected with Pseudomonas syringae pv lachrymans and in uninfected systemic ones. Infection-induced declined net photosynthesis rate and the related changes in transpiration rate, the intracellular CO2 concentration, and prolonged reduction in maximal PSII quantum yield (Fv/Fm), accompanied by an increase in non-photochemical quenching (NPQ), were observed only in the infected leaves, along with full disease symptom development. Infection severely affected the ROS/redox homeostasis at the cellular level and in chloroplasts. Superoxide dismutase, ascorbate, and tocopherol were preferentially induced at the early stage of pathogenesis, whereas catalase, glutathione, and the ascorbate-glutathione cycle enzymes were activated later. Systemic leaves retained their net photosynthesis rate and the changes in the antioxidant system were partly like those in the infected leaves, although they occurred later and were less intense. Re-balancing of ascorbate and glutathione in systemic leaves generated a specific redox signature in chloroplasts. We suggest that it could be a regulatory element playing a role in integrating photosynthesis and redox regulation of stress, aimed at increasing the defense capacity and maintaining the growth of the infected plant.
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Affiliation(s)
- Tomasz Kopczewski
- Department of Plant Physiology and Biochemistry, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 12/16, 90-237 Łódź, Poland;
| | - Elżbieta Kuźniak
- Department of Plant Physiology and Biochemistry, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 12/16, 90-237 Łódź, Poland;
| | - Andrzej Kornaś
- Institute of Biology, Pedagogical University, Podchorążych 2, 30-084 Kraków, Poland; (A.K.); (G.R.); (M.N.)
| | - Grzegorz Rut
- Institute of Biology, Pedagogical University, Podchorążych 2, 30-084 Kraków, Poland; (A.K.); (G.R.); (M.N.)
| | - Michał Nosek
- Institute of Biology, Pedagogical University, Podchorążych 2, 30-084 Kraków, Poland; (A.K.); (G.R.); (M.N.)
| | - Iwona Ciereszko
- Department of Plant Biology and Ecology, Faculty of Biology, University of Bialystok, Ciolkowskiego 1J, 15-245 Bialystok, Poland;
| | - Lech Szczepaniak
- Department of Environmental Chemistry, Faculty of Chemistry, University of Bialystok, Ciolkowskiego 1K, 15-245 Bialystok, Poland;
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5
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Tran BQ, Jung S. Modulation of chloroplast components and defense responses during programmed cell death in tobacco infected with Pseudomonas syringae. Biochem Biophys Res Commun 2020; 528:753-759. [PMID: 32527587 DOI: 10.1016/j.bbrc.2020.05.086] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 05/13/2020] [Indexed: 12/13/2022]
Abstract
We examined how tobacco plants coordinate chloroplast components and defense responses during Pseudomonas syringae pv. tomato (Pst) infection. Tobacco leaves infiltrated with Pst induced weak necrosis at 24 h post-infiltration (hpi) and severe necrosis at 48 hpi. Membrane damage, as shown by cellular leakage and malondialdehyde, and H2O2 production began to increase at 12 hpi and continuously increased at 24-72 hpi in Pst-infiltrated leaves. Pst infection resulted in decreases in light-harvesting chlorophyll-binding proteins (Lhc), Lhcb transcripts, electron transport rate, and Fv/Fm, indicating the impairment in structure and function of photosystem II. Photochemical quenching, qP, continuously decreased in Pst-infiltrated leaves at 24-48 hpi, whereas nonphotochemical quenching, NPQ, exhibited a 2-fold increase at 24 hpi and a decrease at 48 dpi. In response to Pst infection, chlorophyll began to decrease at 48 hpi, whereas levels of protoporphyrin IX (Proto IX), Mg-Proto IX, Mg-Proto methylester, and protochlorophyllide drastically decreased or disappeared as early as 24 hpi. Pst-infiltrated leaves greatly up-regulated the expression of ROS scavenging genes, Fe-SOD, APX, and CAT1, as well as defense-related genes, PII, PR1, PR2, PALa, and CHS1. Our study suggests that the modulation of photosynthetic components during pathogen infection, particularly in relation to the fast degradation of photosensitizing porphyrin intermediates and the increase in photoprotective NPQ, may contribute to attenuating cellular damage in the early stages of programmed cell death induced by Pst.
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Affiliation(s)
- Bao Quoc Tran
- School of Life Sciences and Biotechnology, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, South Korea
| | - Sunyo Jung
- School of Life Sciences and Biotechnology, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, South Korea.
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Zavafer A, González-Solís A, Palacios-Bahena S, Saucedo-García M, Tapia de Aquino C, Vázquez-Santana S, King-Díaz B, Gavilanes-Ruiz M. Organized Disassembly of Photosynthesis During Programmed Cell Death Mediated By Long Chain Bases. Sci Rep 2020; 10:10360. [PMID: 32587330 PMCID: PMC7316715 DOI: 10.1038/s41598-020-65186-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 04/27/2020] [Indexed: 11/09/2022] Open
Abstract
In plants, pathogen triggered programmed cell death (PCD) is frequently mediated by polar lipid molecules referred as long chain bases (LCBs) or ceramides. PCD interceded by LCBs is a well-organized process where several cell organelles play important roles. In fact, light-dependent reactions in the chloroplast have been proposed as major players during PCD, however, the functional aspects of the chloroplast during PCD are largely unknown. For this reason, we investigated events that lead to disassembly of the chloroplast during PCD mediated by LCBs. To do so, LCB elevation was induced with Pseudomonas syringae pv. tomato (a non-host pathogen) or Fumonisin B1 in Phaseolus vulgaris. Then, we performed biochemical tests to detect PCD triggering events (phytosphingosine rises, MPK activation and H2O2 generation) followed by chloroplast structural and functional tests. Observations of the chloroplast, via optical phenotyping methods combined with microscopy, indicated that the loss of photosynthetic linear electron transport coincides with the organized ultrastructure disassembly. In addition, structural changes occurred in parallel with accumulation of H2O2 inside the chloroplast. These features revealed the collapse of chloroplast integrity and function as a mechanism leading to the irreversible execution of the PCD promoted by LCBs.
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Affiliation(s)
- Alonso Zavafer
- Climate Change Cluster, University of Technology Sydney, Faculty of Science Building 4, Level 6 Corner of Thomas and, Harris St, Ultimo NSW 2007, Sydney, Australia
| | - Ariadna González-Solís
- Dpto. de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México (UNAM). Ciudad Universitaria, 04510, Ciudad de México, México
| | - Silvia Palacios-Bahena
- Dpto. de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México (UNAM). Ciudad Universitaria, 04510, Ciudad de México, México
| | - Mariana Saucedo-García
- Instituto de Ciencias Agropecuarias, Universidad Autónoma del Estado de Hidalgo, Tulancingo, Hidalgo, México
| | - Cinthya Tapia de Aquino
- Dpto. de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México (UNAM). Ciudad Universitaria, 04510, Ciudad de México, México
| | - Sonia Vázquez-Santana
- Dpto. de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México (UNAM). Ciudad Universitaria, 04510, Ciudad de México, México
| | - Beatriz King-Díaz
- Dpto. de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México (UNAM). Ciudad Universitaria, 04510, Ciudad de México, México
| | - Marina Gavilanes-Ruiz
- Dpto. de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México (UNAM). Ciudad Universitaria, 04510, Ciudad de México, México.
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Gao C, Xu H, Huang J, Sun B, Zhang F, Savage Z, Duggan C, Yan T, Wu CH, Wang Y, Vleeshouwers VGAA, Kamoun S, Bozkurt TO, Dong S. Pathogen manipulation of chloroplast function triggers a light-dependent immune recognition. Proc Natl Acad Sci U S A 2020; 117:9613-9620. [PMID: 32284406 PMCID: PMC7196767 DOI: 10.1073/pnas.2002759117] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In plants and animals, nucleotide-binding leucine-rich repeat (NLR) proteins are intracellular immune sensors that recognize and eliminate a wide range of invading pathogens. NLR-mediated immunity is known to be modulated by environmental factors. However, how pathogen recognition by NLRs is influenced by environmental factors such as light remains unclear. Here, we show that the agronomically important NLR Rpi-vnt1.1 requires light to confer disease resistance against races of the Irish potato famine pathogen Phytophthora infestans that secrete the effector protein AVRvnt1. The activation of Rpi-vnt1.1 requires a nuclear-encoded chloroplast protein, glycerate 3-kinase (GLYK), implicated in energy production. The pathogen effector AVRvnt1 binds the full-length chloroplast-targeted GLYK isoform leading to activation of Rpi-vnt1.1. In the dark, Rpi-vnt1.1-mediated resistance is compromised because plants produce a shorter GLYK-lacking the intact chloroplast transit peptide-that is not bound by AVRvnt1. The transition between full-length and shorter plant GLYK transcripts is controlled by a light-dependent alternative promoter selection mechanism. In plants that lack Rpi-vnt1.1, the presence of AVRvnt1 reduces GLYK accumulation in chloroplasts counteracting GLYK contribution to basal immunity. Our findings revealed that pathogen manipulation of chloroplast functions has resulted in a light-dependent immune response.
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Affiliation(s)
- Chuyun Gao
- College of Plant Protection, Nanjing Agricultural University, 210095 Nanjing, China
| | - Huawei Xu
- College of Plant Protection, Nanjing Agricultural University, 210095 Nanjing, China
| | - Jie Huang
- College of Plant Protection, Nanjing Agricultural University, 210095 Nanjing, China
| | - Biying Sun
- College of Plant Protection, Nanjing Agricultural University, 210095 Nanjing, China
| | - Fan Zhang
- College of Plant Protection, Nanjing Agricultural University, 210095 Nanjing, China
| | - Zachary Savage
- Imperial College, South Kensington Campus, SW7 2AZ London, United Kingdom
| | - Cian Duggan
- Imperial College, South Kensington Campus, SW7 2AZ London, United Kingdom
| | - Tingxiu Yan
- College of Plant Protection, Nanjing Agricultural University, 210095 Nanjing, China
| | - Chih-Hang Wu
- The Sainsbury Laboratory, University of East Anglia, NR4 7UH Norwich, United Kingdom
| | - Yuanchao Wang
- College of Plant Protection, Nanjing Agricultural University, 210095 Nanjing, China
- Key Laboratory of Plant Immunity, Nanjing Agricultural University, 210095 Nanjing, China
| | - Vivianne G A A Vleeshouwers
- Wageningen University and Research Plant Breeding, Wageningen University and Research, Wageningen 6708 PB, The Netherlands
| | - Sophien Kamoun
- The Sainsbury Laboratory, University of East Anglia, NR4 7UH Norwich, United Kingdom
| | - Tolga O Bozkurt
- Imperial College, South Kensington Campus, SW7 2AZ London, United Kingdom
| | - Suomeng Dong
- College of Plant Protection, Nanjing Agricultural University, 210095 Nanjing, China;
- The Sainsbury Laboratory, University of East Anglia, NR4 7UH Norwich, United Kingdom
- Key Laboratory of Plant Immunity, Nanjing Agricultural University, 210095 Nanjing, China
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8
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Xu Q, Tang C, Wang X, Sun S, Zhao J, Kang Z, Wang X. An effector protein of the wheat stripe rust fungus targets chloroplasts and suppresses chloroplast function. Nat Commun 2019; 10:5571. [PMID: 31804478 PMCID: PMC6895047 DOI: 10.1038/s41467-019-13487-6] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 11/05/2019] [Indexed: 01/02/2023] Open
Abstract
Chloroplasts are important for photosynthesis and for plant immunity against microbial pathogens. Here we identify a haustorium-specific protein (Pst_12806) from the wheat stripe rust fungus, Puccinia striiformis f. sp. tritici (Pst), that is translocated into chloroplasts and affects chloroplast function. Transient expression of Pst_12806 inhibits BAX-induced cell death in tobacco plants and reduces Pseudomonas-induced hypersensitive response in wheat. It suppresses plant basal immunity by reducing callose deposition and the expression of defense-related genes. Pst_12806 is upregulated during infection, and its knockdown (by host-induced gene silencing) reduces Pst growth and development, likely due to increased ROS accumulation. Pst_12806 interacts with the C-terminal Rieske domain of the wheat TaISP protein (a putative component of the cytochrome b6-f complex). Expression of Pst_12806 in plants reduces electron transport rate, photosynthesis, and production of chloroplast-derived ROS. Silencing TaISP by virus-induced gene silencing in a susceptible wheat cultivar reduces fungal growth and uredinium development, suggesting an increase in resistance against Pst infection.
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Affiliation(s)
- Qiang Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Chunlei Tang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Xiaodong Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Shutian Sun
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Jinren Zhao
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| | - Xiaojie Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China.
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9
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Lu Y, Yao J. Chloroplasts at the Crossroad of Photosynthesis, Pathogen Infection and Plant Defense. Int J Mol Sci 2018; 19:E3900. [PMID: 30563149 PMCID: PMC6321325 DOI: 10.3390/ijms19123900] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 11/30/2018] [Accepted: 12/03/2018] [Indexed: 12/31/2022] Open
Abstract
Photosynthesis, pathogen infection, and plant defense are three important biological processes that have been investigated separately for decades. Photosynthesis generates ATP, NADPH, and carbohydrates. These resources are utilized for the synthesis of many important compounds, such as primary metabolites, defense-related hormones abscisic acid, ethylene, jasmonic acid, and salicylic acid, and antimicrobial compounds. In plants and algae, photosynthesis and key steps in the synthesis of defense-related hormones occur in chloroplasts. In addition, chloroplasts are major generators of reactive oxygen species and nitric oxide, and a site for calcium signaling. These signaling molecules are essential to plant defense as well. All plants grown naturally are attacked by pathogens. Bacterial pathogens enter host tissues through natural openings or wounds. Upon invasion, bacterial pathogens utilize a combination of different virulence factors to suppress host defense and promote pathogenicity. On the other hand, plants have developed elaborate defense mechanisms to protect themselves from pathogen infections. This review summarizes recent discoveries on defensive roles of signaling molecules made by plants (primarily in their chloroplasts), counteracting roles of chloroplast-targeted effectors and phytotoxins elicited by bacterial pathogens, and how all these molecules crosstalk and regulate photosynthesis, pathogen infection, and plant defense, using chloroplasts as a major battlefield.
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Affiliation(s)
- Yan Lu
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI 49008, USA.
| | - Jian Yao
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI 49008, USA.
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Kretschmer M, Croll D, Kronstad JW. Chloroplast-associated metabolic functions influence the susceptibility of maize to Ustilago maydis. Mol Plant Pathol 2017; 18:1210-1221. [PMID: 27564650 PMCID: PMC6638283 DOI: 10.1111/mpp.12485] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 08/15/2016] [Accepted: 08/25/2016] [Indexed: 05/10/2023]
Abstract
Biotrophic fungal pathogens must evade or suppress plant defence responses to establish a compatible interaction in living host tissue. In addition, metabolic changes during disease reflect both the impact of nutrient acquisition by the fungus to support proliferation and the integration of metabolism with the plant defence response. In this study, we used transcriptome analyses to predict that the chloroplast and associated functions are important for symptom formation by the biotrophic fungus Ustilago maydis on maize. We tested our prediction by examining the impact on disease of a genetic defect (whirly1) in chloroplast function. In addition, we examined whether disease was influenced by inhibition of glutamine synthetase by glufosinate (impacting amino acid biosynthesis) or inhibition of 3-phosphoshikimate 1-carboxyvinyltransferase by glyphosate (influencing secondary metabolism). All of these perturbations increased the severity of disease, thus suggesting a contribution to resistance. Overall, these findings provide a framework for understanding the components of host metabolism that benefit the plant versus the pathogen during a biotrophic interaction. They also reinforce the emerging importance of the chloroplast as a mediator of plant defence.
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Affiliation(s)
- Matthias Kretschmer
- Michael Smith Laboratories, University of British ColumbiaVancouverBCV6T 1Z4Canada
| | - Daniel Croll
- Michael Smith Laboratories, University of British ColumbiaVancouverBCV6T 1Z4Canada
- Present address:
Institute of Integrative BiologyETH Zürich8092 ZürichSwitzerland
| | - James W. Kronstad
- Michael Smith Laboratories, University of British ColumbiaVancouverBCV6T 1Z4Canada
- Department of Microbiology and ImmunologyUniversity of British ColumbiaVancouverBCV6T 1Z4Canada
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Garcia-Seco D, Chiapello M, Bracale M, Pesce C, Bagnaresi P, Dubois E, Moulin L, Vannini C, Koebnik R. Transcriptome and proteome analysis reveal new insight into proximal and distal responses of wheat to foliar infection by Xanthomonas translucens. Sci Rep 2017; 7:10157. [PMID: 28860643 PMCID: PMC5579275 DOI: 10.1038/s41598-017-10568-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 08/11/2017] [Indexed: 12/22/2022] Open
Abstract
The molecular details of local plant response against Xanthomonas translucens infection is largely unknown. Moreover, there is no knowledge about effects of the pathogen on the root's transcriptome and proteome. Therefore, we investigated the global gene and protein expression changes both in leaves and roots of wheat (Triticum aestivum) 24 h post leaf infection of X. translucens. This simultaneous analysis allowed us to obtain insight into possible metabolic rearrangements in above- and belowground tissues and to identify common responses as well as specific alterations. At the site of infection, we observed the implication of various components of the recognition, signaling, and amplification mechanisms in plant response to the pathogen. Moreover, data indicate a massive down-regulation of photosynthesis and confirm the chloroplast as crucial signaling hub during pathogen attack. Notably, roots responded as well to foliar attack and their response significantly differed from that locally triggered in infected leaves. Data indicate that roots as a site of energy production and synthesis of various secondary metabolites may actively influence the composition and colonisation level of root-associated microbes. Finally, our results emphasize the accumulation of jasmonic acid, pipecolic acid and/or the downstream mediator of hydrogen peroxide as long distal signals from infected leaves to roots.
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Affiliation(s)
- D Garcia-Seco
- IRD, Cirad, Univ. Montpellier, Interactions Plantes Microorganismes Environnement (IPME), 34394, Montpellier, France.
| | - M Chiapello
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, via J.H. Dunant 3, 21100, Varese, Italy
| | - M Bracale
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, via J.H. Dunant 3, 21100, Varese, Italy
| | - C Pesce
- IRD, Cirad, Univ. Montpellier, Interactions Plantes Microorganismes Environnement (IPME), 34394, Montpellier, France
- Université catholique de Louvain, Earth and Life Institute, Applied Microbiology Phytopathology, Louvain-la-Neuve, Belgium
| | - P Bagnaresi
- Council for agricultural research and economics (CREA) - Genomics Research Centre, via San Protaso 302, 29017, Fiorenzuola d'Arda, Piacenza, Italy
| | - E Dubois
- CNRS, Montpellier GenomiX, c/o Institut de Génomique Fonctionnelle, 141 rue de la Cardonille, Montpellier Cedex 34, France
| | - L Moulin
- IRD, Cirad, Univ. Montpellier, Interactions Plantes Microorganismes Environnement (IPME), 34394, Montpellier, France
| | - C Vannini
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, via J.H. Dunant 3, 21100, Varese, Italy.
| | - R Koebnik
- IRD, Cirad, Univ. Montpellier, Interactions Plantes Microorganismes Environnement (IPME), 34394, Montpellier, France
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Ning D, Song A, Fan F, Li Z, Liang Y. Effects of slag-based silicon fertilizer on rice growth and brown-spot resistance. PLoS One 2014; 9:e102681. [PMID: 25036893 PMCID: PMC4103847 DOI: 10.1371/journal.pone.0102681] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 06/21/2014] [Indexed: 11/19/2022] Open
Abstract
It is well documented that slag-based silicon fertilizers have beneficial effects on the growth and disease resistance of rice. However, their effects vary greatly with sources of slag and are closely related to availability of silicon (Si) in these materials. To date, few researches have been done to compare the differences in plant performance and disease resistance between different slag-based silicon fertilizers applied at the same rate of plant-available Si. In the present study both steel and iron slags were chosen to investigate their effects on rice growth and disease resistance under greenhouse conditions. Both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the effects of slags on ultrastructural changes in leaves of rice naturally infected by Bipolaris oryaze, the causal agent of brown spot. The results showed that both slag-based Si fertilizers tested significantly increased rice growth and yield, but decreased brown spot incidence, with steel slag showing a stronger effect than iron slag. The results of SEM analysis showed that application of slags led to more pronounced cell silicification in rice leaves, more silica cells, and more pronounced and larger papilla as well. The results of TEM analysis showed that mesophyll cells of slag-untreated rice leaf were disorganized, with colonization of the fungus (Bipolaris oryzae), including chloroplast degradation and cell wall alterations. The application of slag maintained mesophyll cells relatively intact and increased the thickness of silicon layer. It can be concluded that applying slag-based fertilizer to Si-deficient paddy soil is necessary for improving both rice productivity and brown spot resistance. The immobile silicon deposited in host cell walls and papillae sites is the first physical barrier for fungal penetration, while the soluble Si in the cytoplasm enhances physiological or induced resistance to fungal colonization.
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Affiliation(s)
- Dongfeng Ning
- Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Alin Song
- Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Fenliang Fan
- Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhaojun Li
- Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yongchao Liang
- Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
- Ministry of Education Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
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Ishiga Y, Ishiga T, Uppalapati SR, Mysore KS. Jasmonate ZIM-domain (JAZ) protein regulates host and nonhost pathogen-induced cell death in tomato and Nicotiana benthamiana. PLoS One 2013; 8:e75728. [PMID: 24086622 PMCID: PMC3785428 DOI: 10.1371/journal.pone.0075728] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 08/16/2013] [Indexed: 01/13/2023] Open
Abstract
The nonhost-specific phytotoxin coronatine (COR) produced by several pathovars of Pseudomonas syringae functions as a jasmonic acid-isoleucine (JA-Ile) mimic and contributes to disease development by suppressing plant defense responses and inducing reactive oxygen species in chloroplast. It has been shown that the F-box protein CORONATINE INSENSITIVE 1 (COI1) is the receptor for COR and JA-Ile. JASMONATE ZIM DOMAIN (JAZ) proteins act as negative regulators for JA signaling in Arabidopsis. However, the physiological significance of JAZ proteins in P. syringae disease development and nonhost pathogen-induced hypersensitive response (HR) cell death is not completely understood. In this study, we identified JAZ genes from tomato, a host plant for P. syringae pv. tomato DC3000 (Pst DC3000), and examined their expression profiles in response to COR and pathogens. Most JAZ genes were induced by COR treatment or inoculation with COR-producing Pst DC3000, but not by the COR-defective mutant DB29. Tomato SlJAZ2, SlJAZ6 and SlJAZ7 interacted with SlCOI1 in a COR-dependent manner. Using virus-induced gene silencing (VIGS), we demonstrated that SlJAZ2, SlJAZ6 and SlJAZ7 have no effect on COR-induced chlorosis in tomato and Nicotiana benthamiana. However, SlJAZ2-, SlJAZ6- and SlJAZ7-silenced tomato plants showed enhanced disease-associated cell death to Pst DC3000. Furthermore, we found delayed HR cell death in response to the nonhost pathogen Pst T1 or a pathogen-associated molecular pattern (PAMP), INF1, in SlJAZ2- and SlJAZ6-silenced N. benthamiana. These results suggest that tomato JAZ proteins regulate the progression of cell death during host and nonhost interactions.
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Affiliation(s)
- Yasuhiro Ishiga
- Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, Oklahoma, United States of America
| | - Takako Ishiga
- Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, Oklahoma, United States of America
| | - Srinivasa Rao Uppalapati
- Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, Oklahoma, United States of America
| | - Kirankumar S. Mysore
- Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, Oklahoma, United States of America
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Lubaina AS, Murugan K. Ultrastructural changes and oxidative stress markers in wild and cultivar Sesamum orientale L. following Alternaria sesami (Kawamura) Mohanty and Behera. inoculation. Indian J Exp Biol 2013; 51:670-680. [PMID: 24228391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Alternaria sesami causes leaf spot disease in Sesamum orientale. Conidium germination, inoculation, penetration and colonization of the pathogen on the plant surfaces were studied using scanning electron microscopy. Electron microscopy analysis revealed multiple germ tubes from conidium that spread in all direction across the leaf surfaces. Penetration in the plant surface occured, directly through the epidermis or via stomata with or without the appressoria formation. Hyphal penetration continued through the substomata cavity and some of hyphal branches grew in the intercellular space of mesophyll tissue. Hyphal toxin, caused cell and cell wall damages. Changes in different biochemical parameters in the diseased sesame plants (both in wild and cultivar) were compared to control. Transmission electron microscopy showed structural changes in the chloroplast of diseased plants. Isozyme pattern and assays of different enzymes, namely catalase, acid phosphatase and peroxidase expressed varied level of activities. Meanwhile, esterase, polyphenol oxidase and superoxide dismutase in diseased plants showed remarkable levels compared to control. Due to the infection, chlorophyll content, carbohydrates and total soluble protein decreased whereas free amino acid, proline, phenols and disease-related proteins increased in the host plants. Differential SDS-PAGE band profiling of total soluble proteins were also observed in plants due to the infection.
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Affiliation(s)
- A S Lubaina
- Plant Biochemistry and Molecular Biology Laboratory, Department of Botany, University College, Trivandrum 695 034, India
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Simon UK, Polanschütz LM, Koffler BE, Zechmann B. High resolution imaging of temporal and spatial changes of subcellular ascorbate, glutathione and H₂O₂ distribution during Botrytis cinerea infection in Arabidopsis. PLoS One 2013; 8:e65811. [PMID: 23755284 PMCID: PMC3673919 DOI: 10.1371/journal.pone.0065811] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 05/03/2013] [Indexed: 11/23/2022] Open
Abstract
In order to study the mechanisms behind the infection process of the necrotrophic fungus Botrytis cinerea, the subcellular distribution of hydrogen peroxide (H₂O₂) was monitored over a time frame of 96 h post inoculation (hpi) in Arabidopsis thaliana Col-0 leaves at the inoculation site (IS) and the area around the IS which was defined as area adjacent to the inoculation site (AIS). H₂O₂ accumulation was correlated with changes in the compartment-specific distribution of ascorbate and glutathione and chloroplast fine structure. This study revealed that the severe breakdown of the antioxidative system, indicated by a drop in ascorbate and glutathione contents at the IS at later stages of infection correlated with an accumulation of H₂O₂ in chloroplasts, mitochondria, cell walls, nuclei and the cytosol which resulted in the development of chlorosis and cell death, eventually visible as tissue necrosis. A steady increase of glutathione contents in most cell compartments within infected tissues (up to 600% in chloroplasts at 96 hpi) correlated with an accumulation of H₂O₂ in chloroplasts, mitochondria and cell walls at the AIS indicating that high glutathione levels could not prevent the accumulation of reactive oxygen species (ROS) which resulted in chlorosis. Summing up, this study reveals the intracellular sequence of events during Botrytis cinerea infection and shows that the breakdown of the antioxidative system correlated with the accumulation of H₂O₂ in the host cells. This resulted in the degeneration of the leaf indicated by severe changes in the number and ultrastructure of chloroplasts (e.g. decrease of chloroplast number, decrease of starch and thylakoid contents, increase of plastoglobuli size), chlorosis and necrosis of the leaves.
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Affiliation(s)
- Uwe K. Simon
- Institute of Plant Sciences, University of Graz, Graz, Austria
| | | | | | - Bernd Zechmann
- Institute of Plant Sciences, University of Graz, Graz, Austria
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Jelenska J, Yao N, Vinatzer BA, Wright CM, Brodsky JL, Greenberg JT. A J domain virulence effector of Pseudomonas syringae remodels host chloroplasts and suppresses defenses. Curr Biol 2007; 17:499-508. [PMID: 17350264 PMCID: PMC1857343 DOI: 10.1016/j.cub.2007.02.028] [Citation(s) in RCA: 213] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2006] [Revised: 02/09/2007] [Accepted: 02/12/2007] [Indexed: 11/15/2022]
Abstract
BACKGROUND The plant pathogen Pseudomonas syringae injects 20-40 different proteins called effectors into host plant cells, yet the functions and sites of action of these effectors in promoting pathogenesis are largely unknown. Plants in turn defend themselves against P. syringae by activating the salicylic acid (SA)-mediated signaling pathway. The P. syringae-specific HopI1 effector has a putative chloroplast-targeting sequence and a J domain. J domains function by activating 70 kDa heat-shock proteins (Hsp70). RESULTS HopI1 is a ubiquitous P. syringae virulence effector that acts inside plant cells. When expressed in plants, HopI1 localizes to chloroplasts, the site of SA synthesis. HopI1 causes chloroplast thylakoid structure remodeling and suppresses SA accumulation. HopI1's C terminus has bona fide J domain activity that is necessary for HopI1-mediated virulence and thylakoid remodeling. Furthermore, HopI1-expressing plants have increased heat tolerance, establishing that HopI1 can engage the plant stress-response machinery. CONCLUSIONS These results strongly suggest that chloroplast Hsp70 is targeted by the P. syringae HopI1 effector to promote bacterial virulence by suppressing plant defenses. The targeting of Hsp70 function through J domain proteins is known to occur in a mammalian virus, SV40. However, this is the first example of a bacterial pathogen exploiting a J domain protein to promote pathogenesis through alterations of chloroplast structure and function.
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Affiliation(s)
- Joanna Jelenska
- Department of Molecular Genetics and Cell Biology, The University of Chicago, 1103 East 57 Street, EBC409, Chicago IL 60637, USA
| | - Nan Yao
- Department of Molecular Genetics and Cell Biology, The University of Chicago, 1103 East 57 Street, EBC409, Chicago IL 60637, USA
- State Key Laboratory of Biocontrol, College of Life Science, Sun Yat-sen University, Guangzhou 510275, P.R. China
| | - Boris A. Vinatzer
- Department of Molecular Genetics and Cell Biology, The University of Chicago, 1103 East 57 Street, EBC409, Chicago IL 60637, USA
- Current Address: Department of Plant Pathology, Physiology, and Weed Science, Virginia Polytechnic Institute and State University, Latham Hall, Blacksburg, VA 24061, USA
| | - Christine M. Wright
- Department of Biological Sciences, University of Pittsburgh, 274 Crawford Hall, Pittsburgh PA 15260, USA
| | - Jeffrey L. Brodsky
- Department of Biological Sciences, University of Pittsburgh, 274 Crawford Hall, Pittsburgh PA 15260, USA
| | - Jean T. Greenberg
- Department of Molecular Genetics and Cell Biology, The University of Chicago, 1103 East 57 Street, EBC409, Chicago IL 60637, USA
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Martin W, Rujan T, Richly E, Hansen A, Cornelsen S, Lins T, Leister D, Stoebe B, Hasegawa M, Penny D. Evolutionary analysis of Arabidopsis, cyanobacterial, and chloroplast genomes reveals plastid phylogeny and thousands of cyanobacterial genes in the nucleus. Proc Natl Acad Sci U S A 2002; 99:12246-51. [PMID: 12218172 PMCID: PMC129430 DOI: 10.1073/pnas.182432999] [Citation(s) in RCA: 741] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Chloroplasts were once free-living cyanobacteria that became endosymbionts, but the genomes of contemporary plastids encode only approximately 5-10% as many genes as those of their free-living cousins, indicating that many genes were either lost from plastids or transferred to the nucleus during the course of plant evolution. Previous estimates have suggested that between 800 and perhaps as many as 2,000 genes in the Arabidopsis genome might come from cyanobacteria, but genome-wide phylogenetic surveys that could provide direct estimates of this number are lacking. We compared 24,990 proteins encoded in the Arabidopsis genome to the proteins from three cyanobacterial genomes, 16 other prokaryotic reference genomes, and yeast. Of 9,368 Arabidopsis proteins sufficiently conserved for primary sequence comparison, 866 detected homologues only among cyanobacteria and 834 other branched with cyanobacterial homologues in phylogenetic trees. Extrapolating from these conserved proteins to the whole genome, the data suggest that approximately 4,500 of Arabidopsis protein-coding genes ( approximately 18% of the total) were acquired from the cyanobacterial ancestor of plastids. These proteins encompass all functional classes, and the majority of them are targeted to cell compartments other than the chloroplast. Analysis of 15 sequenced chloroplast genomes revealed 117 nuclear-encoded proteins that are also still present in at least one chloroplast genome. A phylogeny of chloroplast genomes inferred from 41 proteins and 8,303 amino acids sites indicates that at least two independent secondary endosymbiotic events have occurred involving red algae and that amino acid composition bias in chloroplast proteins strongly affects plastid genome phylogeny.
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Affiliation(s)
- William Martin
- Institut für Botanik, Heinrich Heine Universität, Universitätsstrasse 1, 40225 Düsseldorf, Germany.
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Affiliation(s)
- Brian Palenik
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92093-0202, USA.
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Abstract
Microorganisms including bacteria, actinomycetes and fungi were recovered from the leaves of Withania somnifera, which were collected from two altitudinal ranges (0-300 m and 1700-2000 m) in the Asir region, Saudi Arabia. Types and numbers of microorganisms varied according to the altitude and the month of collection. The number of microorganisms was higher on old leaves than that on young ones in most cases. Low altitude exhibited more microorganisms than high altitude. The relationship between meteorological factors and type and number of the recovered microorganisms is discussed. Inoculation of detached healthy leaves of Withania by all recovered fungal species revealed only Alternaria solani as a pathogen of this plant. To confirm pathogenicity, scanning and transmission electron microscopic examination revealed the colonization of this pathogen inside the leaf tissue. Penetration of Withania leaves by the fungus occurred only through stomata, and the invading hyphae were located in the intercellular spaces of leaf tissues. Ultrastructural changes noted in infected cells included changes in chloroplasts and the invagination of the host plasma membrane.
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Affiliation(s)
- H M Alwadi
- Department of Biology, Faculty of Science, King Khalid University, Abha, P.O. Box 9004, Saudi Arabia
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Abstract
A rapid immunostaining procedure for detecting potyviral antigens in individual protoplasts, isolated mesophyll cells, and epidermal strips of Nicotiana tabacum is described. Although all specific antibodies tested detected potyviral antigens in electroporated protoplasts, those against cytoplasmic inclusion (CI) protein provided the most useful results. The number of protoplasts reacting with anti-CI increased with time after inoculation, roughly in parallel with the accumulation of capsid protein, which was measured independently by enzyme-linked immunosorbent assay. Potyviral gene products were also detected in epidermal strips and mesophyll cells separated from systemically infected leaves, indicating that the immunostaining method is generally applicable and that it may prove useful for studying the movement of potyviruses from cell to cell in intact plants.
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Affiliation(s)
- C S Luciano
- Department of Plant Pathology, University of Kentucky, Lexington 40546
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Abstract
The RNA in various subcellular fractions of tobacco etch virus (TEV) infected tissue was analyzed for the presence of complementary viral RNA, and double-stranded viral RNA by hybridization with 32P-labeled viral RNA or cDNA probes. Although viral RNA was detected in several cellular fractions, the complementary RNA of full-length size was found exclusively associated with fractions containing chloroplasts. Treatment of RNAs with RNase before hybridization suggested that the virus-related complementary RNA was present in double-stranded form.
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Martelli GP, Russo M. The fine structure of Cymbidium ringspot virus in host tissues. I. Electron microscopy of systemic infections. J Ultrastruct Res 1981; 77:93-104. [PMID: 7299912 DOI: 10.1016/s0022-5320(81)80069-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Brunt AA, Stace-Smith R, Leung E. Cytological evidence supporting the inclusion of poplar mosaic virus in the carlavirus group of plant viruses. Intervirology 1976; 7:303-8. [PMID: 1010717 DOI: 10.1159/000149962] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The filamentous particles of poplar mosaic virus (PopMV) were detected in palisade, mesophyll and parenchyma cells of systemically infected leaves of Nicotiana clevelandii and N. megalosiphon. The particles were sometimes found scattered throughout the cytoplasm, but more often they occurred loosely associated within ovoid aggregates (up to 3.5 x 1.5 mum) adjacent to chloroplasts and/or mitochondria. PopMV did not induce the formation of 'pinwheel' inclusions, nor other conspicuous ultrastructural or cytopathic effects in infected cells. These observations provide additional evidence that PopMV is a Carlavirus and not a Potyvirus nor a mite-borne virus. PopMV particles were also detected occasionally within plasmodesmata.
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Shalla TA, Petersen LJ, Giunchedi L. Partial characterization of virus-like particles in chloroplasts of plants infected with the U5 strain of TMV. Virology 1975; 66:94-105. [PMID: 1136145 DOI: 10.1016/0042-6822(75)90181-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Kozar FI, Sivers NO. [The use of Triton X-100 for purification of potato virus S]. Mikrobiol Zh 1975; 37:240-2. [PMID: 1214645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Hatta T, Bullivant S, Matthews RE. Fine structure of vesicles induced in chloroplasts of Chinese cabbage leaves by infection with turnip yellow mosaic virus. J Gen Virol 1973; 20:37-50. [PMID: 4584930 DOI: 10.1099/0022-1317-20-1-37] [Citation(s) in RCA: 43] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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