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Youssef RM, MacDonald MH, Brewer EP, Bauchan GR, Kim KH, Matthews BF. Ectopic expression of AtPAD4 broadens resistance of soybean to soybean cyst and root-knot nematodes. BMC PLANT BIOLOGY 2013; 13:67. [PMID: 23617694 PMCID: PMC3648381 DOI: 10.1186/1471-2229-13-67] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 04/22/2013] [Indexed: 05/03/2023]
Abstract
BACKGROUND The gene encoding PAD4 (PHYTOALEXIN-DEFICIENT4) is required in Arabidopsis for expression of several genes involved in the defense response to Pseudomonas syringae pv. maculicola. AtPAD4 (Arabidopsis thaliana PAD4) encodes a lipase-like protein that plays a regulatory role mediating salicylic acid signaling. RESULTS We expressed the gene encoding AtPAD4 in soybean roots of composite plants to test the ability of AtPAD4 to deter plant parasitic nematode development. The transformed roots were challenged with two different plant parasitic nematode genera represented by soybean cyst nematode (SCN; Heterodera glycines) and root-knot nematode (RKN; Meloidogyne incognita). Expression of AtPAD4 in soybean roots decreased the number of mature SCN females 35 days after inoculation by 68 percent. Similarly, soybean roots expressing AtPAD4 exhibited 77 percent fewer galls when challenged with RKN. CONCLUSIONS Our experiments show that AtPAD4 can be used in an economically important crop, soybean, to provide a measure of resistance to two different genera of nematodes.
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Affiliation(s)
- Reham M Youssef
- USDA-ARS, Soybean Genomic and Improvement Laboratory, 10300 Baltimore Ave, Bldg 006, Beltsville, MD, 20705, USA
- Plant Protection Department, Faculty of Agriculture, Fayoum University, Fayoum, Egypt
| | - Margaret H MacDonald
- USDA-ARS, Soybean Genomic and Improvement Laboratory, 10300 Baltimore Ave, Bldg 006, Beltsville, MD, 20705, USA
| | - Eric P Brewer
- USDA-ARS, Soybean Genomic and Improvement Laboratory, 10300 Baltimore Ave, Bldg 006, Beltsville, MD, 20705, USA
| | - Gary R Bauchan
- USDA-ARS, Soybean Genomic and Improvement Laboratory, 10300 Baltimore Ave, Bldg 006, Beltsville, MD, 20705, USA
| | - Kyung-Hwan Kim
- Cell and Genetics Division, National Institute of Agricultural Biotechnology, Rural Development Administration, Suwon, 441-100, South Korea
| | - Benjamin F Matthews
- USDA-ARS, Soybean Genomic and Improvement Laboratory, 10300 Baltimore Ave, Bldg 006, Beltsville, MD, 20705, USA
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102
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Lucas WJ, Groover A, Lichtenberger R, Furuta K, Yadav SR, Helariutta Y, He XQ, Fukuda H, Kang J, Brady SM, Patrick JW, Sperry J, Yoshida A, López-Millán AF, Grusak MA, Kachroo P. The plant vascular system: evolution, development and functions. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2013; 55:294-388. [PMID: 23462277 DOI: 10.1111/jipb.12041] [Citation(s) in RCA: 398] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The emergence of the tracheophyte-based vascular system of land plants had major impacts on the evolution of terrestrial biology, in general, through its role in facilitating the development of plants with increased stature, photosynthetic output, and ability to colonize a greatly expanded range of environmental habitats. Recently, considerable progress has been made in terms of our understanding of the developmental and physiological programs involved in the formation and function of the plant vascular system. In this review, we first examine the evolutionary events that gave rise to the tracheophytes, followed by analysis of the genetic and hormonal networks that cooperate to orchestrate vascular development in the gymnosperms and angiosperms. The two essential functions performed by the vascular system, namely the delivery of resources (water, essential mineral nutrients, sugars and amino acids) to the various plant organs and provision of mechanical support are next discussed. Here, we focus on critical questions relating to structural and physiological properties controlling the delivery of material through the xylem and phloem. Recent discoveries into the role of the vascular system as an effective long-distance communication system are next assessed in terms of the coordination of developmental, physiological and defense-related processes, at the whole-plant level. A concerted effort has been made to integrate all these new findings into a comprehensive picture of the state-of-the-art in the area of plant vascular biology. Finally, areas important for future research are highlighted in terms of their likely contribution both to basic knowledge and applications to primary industry.
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Affiliation(s)
- William J Lucas
- Department of Plant Biology, College of Biological Sciences, University of California, Davis, CA 95616, USA.
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Naidoo R, Ferreira L, Berger DK, Myburg AA, Naidoo S. The identification and differential expression of Eucalyptus grandis pathogenesis-related genes in response to salicylic acid and methyl jasmonate. FRONTIERS IN PLANT SCIENCE 2013; 4:43. [PMID: 23508356 PMCID: PMC3589731 DOI: 10.3389/fpls.2013.00043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 02/19/2013] [Indexed: 05/08/2023]
Abstract
Two important role players in plant defence response are the phytohormones salicylic acid (SA) and jasmonic acid (JA); both of which have been well described in model species such as Arabidopsis thaliana. Several pathogenesis related (PR) genes have previously been used as indicators of the onset of SA and JA signaling in Arabidopsis. This information is lacking in tree genera such as Eucalyptus. The aim of this study was to characterize the transcriptional response of PR genes (EgrPR2, EgrPR3, EgrPR4, EgrPR5, and EgrLOX) identified in Eucalyptus grandis to SA and methyl jasmonate (MeJA) treatment as well as to qualify them as diagnostic for the two signaling pathways. Using the genome sequence of E. grandis, we identified candidate Eucalyptus orthologs EgrPR2, EgrPR3, EgrPR4, EgrPR5, and EgrLOX based on a co-phylogenetic approach. The expression of these genes was investigated after various doses of SA and MeJA (a derivative of JA) treatment as well as at various time points. The transcript levels of EgrPR2 were decreased in response to high concentrations of MeJA whereas the expression of EgrPR3 and EgrLOX declined as the concentrations of SA treatment increased, suggesting an antagonistic relationship between SA and MeJA. Our results support EgrPR2 as potentially diagnostic for SA and EgrPR3, EgrPR4, and EgrLOX as indicators of MeJA signaling. To further validate the diagnostic potential of the PR genes we challenged E. grandis clones with the fungal necrotrophic pathogen Chrysoporthe austroafricana. The tolerant clone showed high induction of EgrPR2 and decreased transcript abundance of EgrPR4. Pre-treatment of the susceptible genotype with 5 mM SA resulted in lesion lengths comparable to the tolerant genotype after artificial inoculation with C. austroafricana. Thus expression profiling of EgrPR2 and EgrPR4 genes could serve as a useful diagnostic approach to determine which of the two signaling pathways are activated against various pathogens in Eucalyptus.
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Affiliation(s)
- Ronishree Naidoo
- Department of Genetics, University of PretoriaPretoria, South Africa
- Forestry and Agricultural Biotechnology Institute, University of PretoriaPretoria, South Africa
| | - Linda Ferreira
- Department of Genetics, University of PretoriaPretoria, South Africa
- Forestry and Agricultural Biotechnology Institute, University of PretoriaPretoria, South Africa
| | - Dave K. Berger
- Forestry and Agricultural Biotechnology Institute, University of PretoriaPretoria, South Africa
- Department of Plant Science, University of PretoriaPretoria, South Africa
| | - Alexander A. Myburg
- Department of Genetics, University of PretoriaPretoria, South Africa
- Forestry and Agricultural Biotechnology Institute, University of PretoriaPretoria, South Africa
| | - Sanushka Naidoo
- Department of Genetics, University of PretoriaPretoria, South Africa
- Forestry and Agricultural Biotechnology Institute, University of PretoriaPretoria, South Africa
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104
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Wang Y, An C, Zhang X, Yao J, Zhang Y, Sun Y, Yu F, Amador DM, Mou Z. The Arabidopsis elongator complex subunit2 epigenetically regulates plant immune responses. THE PLANT CELL 2013; 25:762-76. [PMID: 23435660 PMCID: PMC3608791 DOI: 10.1105/tpc.113.109116] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 01/29/2013] [Accepted: 02/04/2013] [Indexed: 05/17/2023]
Abstract
The Arabidopsis thaliana Elongator complex subunit2 (ELP2) genetically interacts with NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1), a key transcription coactivator of plant immunity, and regulates the induction kinetics of defense genes. However, the mechanistic relationship between ELP2 and NPR1 and how ELP2 regulates the kinetics of defense gene induction are unclear. Here, we demonstrate that ELP2 is an epigenetic regulator required for pathogen-induced rapid transcriptome reprogramming. We show that ELP2 functions in a transcriptional feed-forward loop regulating both NPR1 and its target genes. An elp2 mutation increases the total methylcytosine number, reduces the average methylation levels of methylcytosines, and alters (increases or decreases) methylation levels of specific methylcytosines. Interestingly, infection of plants with the avirulent bacterial pathogen Pseudomonas syringae pv tomato DC3000/avrRpt2 induces biphasic changes in DNA methylation levels of NPR1 and PHYTOALEXIN DEFICIENT4 (PAD4), which encodes another key regulator of plant immunity. These dynamic changes are blocked by the elp2 mutation, which is correlated with delayed induction of NPR1 and PAD4. The elp2 mutation also reduces basal histone acetylation levels in the coding regions of several defense genes. Together, our data demonstrate a new role for Elongator in somatic DNA demethylation/methylation and suggest a function for Elongator-mediated chromatin regulation in pathogen-induced transcriptome reprogramming.
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Affiliation(s)
- Yongsheng Wang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611
| | - Chuanfu An
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611
| | - Xudong Zhang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611
| | - Jiqiang Yao
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610
| | - Yanping Zhang
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610
| | - Yijun Sun
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610
| | - Fahong Yu
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610
| | - David Moraga Amador
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611
- Address correspondence to
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105
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Fu ZQ, Dong X. Systemic acquired resistance: turning local infection into global defense. ANNUAL REVIEW OF PLANT BIOLOGY 2013; 64:839-63. [PMID: 23373699 DOI: 10.1146/annurev-arplant-042811-105606] [Citation(s) in RCA: 785] [Impact Index Per Article: 71.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Systemic acquired resistance (SAR) is an induced immune mechanism in plants. Unlike vertebrate adaptive immunity, SAR is broad spectrum, with no specificity to the initial infection. An avirulent pathogen causing local programmed cell death can induce SAR through generation of mobile signals, accumulation of the defense hormone salicylic acid, and secretion of the antimicrobial PR (pathogenesis-related) proteins. Consequently, the rest of the plant is protected from secondary infection for a period of weeks to months. SAR can even be passed on to progeny through epigenetic regulation. The Arabidopsis NPR1 (nonexpresser of PR genes 1) protein is a master regulator of SAR. Recent study has shown that salicylic acid directly binds to the NPR1 adaptor proteins NPR3 and NPR4, regulates their interactions with NPR1, and controls NPR1 protein stability. However, how NPR1 interacts with TGA transcription factors to activate defense gene expression is still not well understood. In addition, redox regulators, the mediator complex, WRKY transcription factors, endoplasmic reticulum-resident proteins, and DNA repair proteins play critical roles in SAR.
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Affiliation(s)
- Zheng Qing Fu
- Howard Hughes Medical Institute-Gordon and Betty Moore Foundation and Department of Biology, Duke University, Durham, NC 27708, USA
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106
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Chi YH, Paeng SK, Kim MJ, Hwang GY, Melencion SMB, Oh HT, Lee SY. Redox-dependent functional switching of plant proteins accompanying with their structural changes. FRONTIERS IN PLANT SCIENCE 2013; 4:277. [PMID: 23898340 PMCID: PMC3724125 DOI: 10.3389/fpls.2013.00277] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 07/08/2013] [Indexed: 05/21/2023]
Abstract
Reactive oxygen species (ROS) can be generated during the course of normal aerobic metabolism or when an organism is exposed to a variety of stress conditions. It can cause a widespread damage to intracellular macromolecules and play a causal role in many degenerative diseases. Like other aerobic organisms plants are also equipped with a wide range of antioxidant redox proteins, such as superoxide dismutase, catalase, glutaredoxin, thioredoxin (Trx), Trx reductase, protein disulfide reductase, and other kinds of peroxidases that are usually significant in preventing harmful effects of ROS. To defend plant cells in response to stimuli, a part of redox proteins have shown to play multiple functions through the post-translational modification with a redox-dependent manner. For the alternative switching of their cellular functions, the redox proteins change their protein structures from low molecular weight to high molecular weight (HMW) protein complexes depending on the external stress. The HMW proteins are reported to act as molecular chaperone, which enable the plants to enhance their stress tolerance. In addition, some transcription factors and co-activators have function responding to environmental stresses by redox-dependent structural changes. This review describes the molecular mechanism and physiological significance of the redox proteins, transcription factors and co-activators to protect the plants from environmental stresses through the redox-dependent structural and functional switching of the plant redox proteins.
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Affiliation(s)
| | | | | | | | | | | | - Sang Yeol Lee
- *Correspondence: Sang Yeol Lee, Division of Applied Life Sciences, Gyeongsang National University, Jinjudaero 501, Jinju 660-701, Korea e-mail:
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107
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Sanchez L, Courteaux B, Hubert J, Kauffmann S, Renault JH, Clément C, Baillieul F, Dorey S. Rhamnolipids elicit defense responses and induce disease resistance against biotrophic, hemibiotrophic, and necrotrophic pathogens that require different signaling pathways in Arabidopsis and highlight a central role for salicylic acid. PLANT PHYSIOLOGY 2012; 160:1630-41. [PMID: 22968829 PMCID: PMC3490604 DOI: 10.1104/pp.112.201913] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 09/06/2012] [Indexed: 05/19/2023]
Abstract
Plant resistance to phytopathogenic microorganisms mainly relies on the activation of an innate immune response usually launched after recognition by the plant cells of microbe-associated molecular patterns. The plant hormones, salicylic acid (SA), jasmonic acid, and ethylene have emerged as key players in the signaling networks involved in plant immunity. Rhamnolipids (RLs) are glycolipids produced by bacteria and are involved in surface motility and biofilm development. Here we report that RLs trigger an immune response in Arabidopsis (Arabidopsis thaliana) characterized by signaling molecules accumulation and defense gene activation. This immune response participates to resistance against the hemibiotrophic bacterium Pseudomonas syringae pv tomato, the biotrophic oomycete Hyaloperonospora arabidopsidis, and the necrotrophic fungus Botrytis cinerea. We show that RL-mediated resistance involves different signaling pathways that depend on the type of pathogen. Ethylene is involved in RL-induced resistance to H. arabidopsidis and to P. syringae pv tomato whereas jasmonic acid is essential for the resistance to B. cinerea. SA participates to the restriction of all pathogens. We also show evidence that SA-dependent plant defenses are potentiated by RLs following challenge by B. cinerea or P. syringae pv tomato. These results highlight a central role for SA in RL-mediated resistance. In addition to the activation of plant defense responses, antimicrobial properties of RLs are thought to participate in the protection against the fungus and the oomycete. Our data highlight the intricate mechanisms involved in plant protection triggered by a new type of molecule that can be perceived by plant cells and that can also act directly onto pathogens.
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Affiliation(s)
- Lisa Sanchez
- Laboratoire de Stress, Défenses, et Reproduction des Plantes, L'Unité de Recherche Vignes et Vins de Champagne, Equipe d'Accueil 4707 (L.S., B.C., C.C., F.B., S.D.) and Institut de Chimie Moléculaire de Reims Unité Mixte de Recherche, Centre National de la Recherche Scientifique 6229, Institut Fédératif Recherche 53 (J.H., J.-H.R.), Université de Reims Champagne-Ardenne, F-51687 Reims cedex 2, France; and Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2357, F-67084 Strasbourg, France (S.K.)
| | - Barbara Courteaux
- Laboratoire de Stress, Défenses, et Reproduction des Plantes, L'Unité de Recherche Vignes et Vins de Champagne, Equipe d'Accueil 4707 (L.S., B.C., C.C., F.B., S.D.) and Institut de Chimie Moléculaire de Reims Unité Mixte de Recherche, Centre National de la Recherche Scientifique 6229, Institut Fédératif Recherche 53 (J.H., J.-H.R.), Université de Reims Champagne-Ardenne, F-51687 Reims cedex 2, France; and Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2357, F-67084 Strasbourg, France (S.K.)
| | - Jane Hubert
- Laboratoire de Stress, Défenses, et Reproduction des Plantes, L'Unité de Recherche Vignes et Vins de Champagne, Equipe d'Accueil 4707 (L.S., B.C., C.C., F.B., S.D.) and Institut de Chimie Moléculaire de Reims Unité Mixte de Recherche, Centre National de la Recherche Scientifique 6229, Institut Fédératif Recherche 53 (J.H., J.-H.R.), Université de Reims Champagne-Ardenne, F-51687 Reims cedex 2, France; and Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2357, F-67084 Strasbourg, France (S.K.)
| | | | - Jean-Hugues Renault
- Laboratoire de Stress, Défenses, et Reproduction des Plantes, L'Unité de Recherche Vignes et Vins de Champagne, Equipe d'Accueil 4707 (L.S., B.C., C.C., F.B., S.D.) and Institut de Chimie Moléculaire de Reims Unité Mixte de Recherche, Centre National de la Recherche Scientifique 6229, Institut Fédératif Recherche 53 (J.H., J.-H.R.), Université de Reims Champagne-Ardenne, F-51687 Reims cedex 2, France; and Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2357, F-67084 Strasbourg, France (S.K.)
| | - Christophe Clément
- Laboratoire de Stress, Défenses, et Reproduction des Plantes, L'Unité de Recherche Vignes et Vins de Champagne, Equipe d'Accueil 4707 (L.S., B.C., C.C., F.B., S.D.) and Institut de Chimie Moléculaire de Reims Unité Mixte de Recherche, Centre National de la Recherche Scientifique 6229, Institut Fédératif Recherche 53 (J.H., J.-H.R.), Université de Reims Champagne-Ardenne, F-51687 Reims cedex 2, France; and Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2357, F-67084 Strasbourg, France (S.K.)
| | - Fabienne Baillieul
- Laboratoire de Stress, Défenses, et Reproduction des Plantes, L'Unité de Recherche Vignes et Vins de Champagne, Equipe d'Accueil 4707 (L.S., B.C., C.C., F.B., S.D.) and Institut de Chimie Moléculaire de Reims Unité Mixte de Recherche, Centre National de la Recherche Scientifique 6229, Institut Fédératif Recherche 53 (J.H., J.-H.R.), Université de Reims Champagne-Ardenne, F-51687 Reims cedex 2, France; and Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2357, F-67084 Strasbourg, France (S.K.)
| | - Stéphan Dorey
- Laboratoire de Stress, Défenses, et Reproduction des Plantes, L'Unité de Recherche Vignes et Vins de Champagne, Equipe d'Accueil 4707 (L.S., B.C., C.C., F.B., S.D.) and Institut de Chimie Moléculaire de Reims Unité Mixte de Recherche, Centre National de la Recherche Scientifique 6229, Institut Fédératif Recherche 53 (J.H., J.-H.R.), Université de Reims Champagne-Ardenne, F-51687 Reims cedex 2, France; and Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2357, F-67084 Strasbourg, France (S.K.)
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108
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Kumar V, Joshi SG, Bell AA, Rathore KS. Enhanced resistance against Thielaviopsis basicola in transgenic cotton plants expressing Arabidopsis NPR1 gene. Transgenic Res 2012; 22:359-68. [PMID: 23001518 DOI: 10.1007/s11248-012-9652-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 09/05/2012] [Indexed: 11/25/2022]
Abstract
Black root rot, caused by Thielaviopsis basicola, is an important disease in several crops including cotton. We studied the response of Arabidopsis NPR1 (AtNPR1)-expressing cotton lines, previously shown to be highly resistant to a diverse set of pathogens, to a challenge from T. basicola. In four different experiments, we found significant degree of tolerance in the transgenic lines to black root rot. Although transformants showed the typical root discoloration symptoms similar to the wild-type control plants following infection, their roots tended to recover faster and resumed normal growth. Better performance of transgenic plants is reflected by the fact that they have significantly higher shoot and root mass, longer shoot length, and greater number of boll-set. Transcriptional analysis of the defense response showed that the roots of AtNPR1-overexpressing transgenic plants exhibited stronger and faster induction of most of these defense-related genes, particularly PR1, thaumatin, glucanase, LOX1, and chitinase. The results obtained in this investigation provide further support for a broad-spectrum nature of the resistance conferred by overexpression of AtNPR1 gene in cotton.
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Affiliation(s)
- Vinod Kumar
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX 77843-2123, USA
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109
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Kim HS, Park HC, Kim KE, Jung MS, Han HJ, Kim SH, Kwon YS, Bahk S, An J, Bae DW, Yun DJ, Kwak SS, Chung WS. A NAC transcription factor and SNI1 cooperatively suppress basal pathogen resistance in Arabidopsis thaliana. Nucleic Acids Res 2012; 40:9182-92. [PMID: 22826500 PMCID: PMC3467076 DOI: 10.1093/nar/gks683] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Transcriptional repression of pathogen defense-related genes is essential for plant growth and development. Several proteins are known to be involved in the transcriptional regulation of plant defense responses. However, mechanisms by which expression of defense-related genes are regulated by repressor proteins are poorly characterized. Here, we describe the in planta function of CBNAC, a calmodulin-regulated NAC transcriptional repressor in Arabidopsis. A T-DNA insertional mutant (cbnac1) displayed enhanced resistance to a virulent strain of the bacterial pathogen Pseudomonas syringae DC3000 (PstDC3000), whereas resistance was reduced in transgenic CBNAC overexpression lines. The observed changes in disease resistance were correlated with alterations in pathogenesis-related protein 1 (PR1) gene expression. CBNAC bound directly to the PR1 promoter. SNI1 (suppressor of nonexpressor of PR genes1, inducible 1) was identified as a CBNAC-binding protein. Basal resistance to PstDC3000 and derepression of PR1 expression was greater in the cbnac1 sni1 double mutant than in either cbnac1 or sni1 mutants. SNI1 enhanced binding of CBNAC to its cognate PR1 promoter element. CBNAC and SNI1 are hypothesized to work as repressor proteins in the cooperative suppression of plant basal defense.
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Affiliation(s)
- Ho Soo Kim
- Division of Applied Life Science (BK21 Program), Gyeongsang National University, Jinju 660-701, Korea
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110
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Choi SM, Song HR, Han SK, Han M, Kim CY, Park J, Lee YH, Jeon JS, Noh YS, Noh B. HDA19 is required for the repression of salicylic acid biosynthesis and salicylic acid-mediated defense responses in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 71:135-46. [PMID: 22381007 DOI: 10.1111/j.1365-313x.2012.04977.x] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
To cope with a lifetime of exposure to a variety of pathogens, plants have developed exquisite and refined defense mechanisms that vary depending on the type of attacking pathogen. Defense-associated transcriptional reprogramming is a central part of plant defense mechanisms. Chromatin modification has recently been shown to be another layer of regulation for plant defense mechanisms. Here, we show that the RPD3/HDA1-class histone deacetylase HDA19 is involved in the repression of salicylic acid (SA)-mediated defense responses in Arabidopsis. Loss of HDA19 activity increased SA content and increased the expression of a group of genes required for accumulation of SA as well as pathogenesis related (PR) genes, resulting in enhanced resistance to Pseudomonas syringae. We found that HDA19 directly associates with and deacetylates histones at the PR1 and PR2 promoters. Thus, our study shows that HDA19, by modifying chromatin to a repressive state, ensures low basal expression of defense genes, such as PR1, under unchallenged conditions, as well as their proper induction without overstimulation during defense responses to pathogen attacks. Thus, the role of HDA19 might be critical in preventing unnecessary activation and self-destructive overstimulation of defense responses, allowing successful growth and development.
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Affiliation(s)
- Sun-Mee Choi
- School of Biological Sciences, Seoul National University, Seoul 151-742, Korea
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111
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Zhang JY, Qiao YS, Lv D, Gao ZH, Qu SC, Zhang Z. Malus hupehensis NPR1 induces pathogenesis-related protein gene expression in transgenic tobacco. PLANT BIOLOGY (STUTTGART, GERMANY) 2012; 14 Suppl 1:46-56. [PMID: 21973266 DOI: 10.1111/j.1438-8677.2011.00483.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Most commercially grown apple cultivars are susceptible to fungal diseases. Malus hupehensis has high resistance to many diseases affecting apple cultivars. Understanding innate defence mechanisms would help to develop disease-resistant apple crops. Non-expressor of pathogenesis-related genes 1 (NPR1) plays a key role in regulating salicylic acid (SA)-mediated systemic acquired resistance (SAR). MhNPR1 cDNA, corresponding to genomic DNA and its 5' flanking sequences, was isolated from M. hupehensis. Sequence analysis showed that the regulatory mechanism for oligomer-monomer transition of the MhNPR1 protein in apple might be similar to that of GmNPR1 in soybean, but different from that of AtNPR1 in Arabidopsis. No significant differences in MhNPR1 expression were found in M. hupehensis after infection with Botryosphaeria berengeriana, showing that MhNPR1 might be regulated by pathogens at the protein level, as described for Arabidopsis and grapevine. SA treatment significantly induced MhNPR1 expression in leaves, stems and roots, while methyl jasmonate (MeJA) treatment induced MhNPR1 expression in roots, but not in leaves or stems. The expression of MhNPR1 was highly increased in roots, moderately in leaves, and did not change in stems after treatment with 1-aminocyclopropane-1-carboxylic acid (ACC). SAR marker genes (MhPR1 and MhPR5) were induced by SA, MeJA and ACC in leaves, stems and roots. Overexpression of MhNPR1 significantly induced the expression of pathogenesis-related genes (NtPR1, NtPR3 and NtPR5) in transgenic tobacco plants and resistance to the fungus Botrytis cinerea, suggesting that MhNPR1 orthologues are a component of the SA defence signalling pathway and SAR is induced in M. hupehensis.
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Affiliation(s)
- J-Y Zhang
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
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112
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Makandar R, Nalam VJ, Lee H, Trick HN, Dong Y, Shah J. Salicylic acid regulates basal resistance to Fusarium head blight in wheat. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2012; 25:431-9. [PMID: 22112217 DOI: 10.1094/mpmi-09-11-0232] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Fusarium head blight (FHB) is a destructive disease of cereal crops such as wheat and barley. Previously, expression in wheat of the Arabidopsis NPR1 gene (AtNPR1), which encodes a key regulator of salicylic acid (SA) signaling, was shown to reduce severity of FHB caused by Fusarium graminearum. It was hypothesized that SA signaling contributes to wheat defense against F. graminearum. Here, we show that increased accumulation of SA in fungus-infected spikes correlated with elevated expression of the SA-inducible pathogenesis-related 1 (PR1) gene and FHB resistance. In addition, FHB severity and mycotoxin accumulation were curtailed in wheat plants treated with SA and in AtNPR1 wheat, which is hyper-responsive to SA. In support of a critical role for SA in basal resistance to FHB, disease severity was higher in wheat expressing the NahG-encoded salicylate hydroxylase, which metabolizes SA. The FHB-promoting effect of NahG was overcome by application of benzo (1,2,3), thiadiazole-7 carbothioic acid S-methyl ester, a synthetic functional analog of SA, thus confirming an important role for SA signaling in basal resistance to FHB. We further demonstrate that jasmonate signaling has a dichotomous role in wheat interaction with F. graminearum, constraining activation of SA signaling during early stages of infection and promoting resistance during the later stages of infection.
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Affiliation(s)
- Ragiba Makandar
- Department of Biological Sciences, University of North Texas, Denton 76230, USA
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113
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Chern M, Bai W, Sze-To WH, Canlas PE, Bartley LE, Ronald PC. A rice transient assay system identifies a novel domain in NRR required for interaction with NH1/OsNPR1 and inhibition of NH1-mediated transcriptional activation. PLANT METHODS 2012; 8:6. [PMID: 22353606 PMCID: PMC3297495 DOI: 10.1186/1746-4811-8-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 02/21/2012] [Indexed: 05/17/2023]
Abstract
BACKGROUND Arabidopsis NPR1 is a master regulator of systemic acquired resistance. NPR1 binds to TGA transcription factors and functions as a transcriptional co-activator. In rice, NH1/OsNPR1 functions to enhance innate immunity. NRR disrupts NH1 function, when over-expressed. RESULTS We have established a rice transient protoplast assay to demonstrate that NH1 is a transcriptional co-activator and that NRR represses NH1-mediated activation. We identified three NRR homologues (RH1, RH2, and RH3). RH1 and RH3, but not RH2, also effectively repress NH1-mediated transcriptional activation. NRR, RH1, RH2, and RH3 share sequence similarity in a region beyond the previously identified NPR1-interacting domain. This region is required for strong interaction with NH1. A double point mutation, W66A/F70A, in this novel NH1-interacting domain severely reduces interaction with NH1. Mutation W66A/F70A also greatly reduces the ability of NRR to repress NH1-mediated activation. RH2 carries a deviation (amino acids AV) in this region as compared to consensus sequences (amino acids ED) among NRR, RH1, and RH3. A substitution (AV to ED) in RH2 results in strong binding of mutant RH2ED to NH1 and effective repression of NH1-mediated activation. CONCLUSIONS The protoplast-based transient system can be used to dissect protein domains associated with their functions. Our results demonstrate that the ability of NRR and its homologues to repress NH1-mediated transcriptional activation is tightly correlated with their ability to bind to NH1. Furthermore, a sequence is identified as a novel NH1-interacting domain. Importantly, this novel sequence is widely present in plant species, from cereals to castor bean plants, to poplar trees, to Arabidopsis, indicating its significance in plants.
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Affiliation(s)
- Mawsheng Chern
- Department of Plant Pathology, University of California, Davis, Davis, CA 95616, USA
| | - Wei Bai
- Department of Plant Pathology, University of California, Davis, Davis, CA 95616, USA
- College of Life Sciences, Inner Mongolia Agricultural University., Huhhot 010018, China
| | - Wing Hoi Sze-To
- Department of Plant Pathology, University of California, Davis, Davis, CA 95616, USA
| | - Patrick E Canlas
- Department of Plant Pathology, University of California, Davis, Davis, CA 95616, USA
| | - Laura E Bartley
- Department of Plant Pathology, University of California, Davis, Davis, CA 95616, USA
- Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73019, USA
| | - Pamela C Ronald
- Department of Plant Pathology, University of California, Davis, Davis, CA 95616, USA
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114
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Velazquez-Robledo R, Contreras-Cornejo HA, Macias-Rodriguez L, Hernandez-Morales A, Aguirre J, Casas-Flores S, Lopez-Bucio J, Herrera-Estrella A. Role of the 4-phosphopantetheinyl transferase of Trichoderma virens in secondary metabolism and induction of plant defense responses. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2011; 24:1459-1471. [PMID: 21830953 DOI: 10.1094/mpmi-02-11-0045] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Trichoderma virens is a ubiquitous soil fungus successfully used in biological control due to its efficient colonization of plant roots. In fungi, 4-phosphopantetheinyl transferases (PPTases) activate enzymes involved in primary and secondary metabolism. Therefore, we cloned the PPTase gene ppt1 from T. virens and generated PPTase-deficient (?ppt1) and overexpressing strains to investigate the role of this enzyme in biocontrol and induction of plant defense responses. The ?ppt1 mutants were auxotrophic for lysine, produced nonpigmented conidia, and were unable to synthesize nonribosomal peptides. Although spore germination was severely compromised under both low and high iron availability, mycelial growth occurred faster than the wild type, and the mutants were able to efficiently colonize plant roots. The ?ppt1 mutants were unable of inhibiting growth of phytopathogenic fungi in vitro. Arabidopsis thaliana seedlings co-cultivated with wild-type T. virens showed increased expression of pPr1a:uidA and pLox2:uidA markers, which correlated with enhanced accumulation of salicylic acid (SA), jasmonic acid, camalexin, and resistance to Botrytis cinerea. Co-cultivation of A. thaliana seedlings with ?ppt1 mutants compromised the SA and camalexin responses, resulting in decreased protection against the pathogen. Our data reveal an important role of T. virens PPT1 in antibiosis and induction of SA and camalexin-dependent plant defense responses.
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115
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Jing B, Xu S, Xu M, Li Y, Li S, Ding J, Zhang Y. Brush and spray: a high-throughput systemic acquired resistance assay suitable for large-scale genetic screening. PLANT PHYSIOLOGY 2011; 157:973-80. [PMID: 21900483 PMCID: PMC3252141 DOI: 10.1104/pp.111.182089] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 09/04/2011] [Indexed: 05/20/2023]
Abstract
Systemic acquired resistance (SAR) is a defense mechanism induced in the distal parts of plants after primary infection. It confers long-lasting protection against a broad spectrum of microbial pathogens. Lack of high-throughput assays has hampered the forward genetic analysis of SAR. Here, we report the development of an easy and efficient assay for SAR and its application in a forward genetic screen for SAR-deficient mutants in Arabidopsis (Arabidopsis thaliana). Using the new assay for SAR, we identified six flavin-dependent monooxygenase1, four AGD2-like defense response protein1, three salicylic acid induction-deficient2, one phytoalexin deficient4, and one avrPphB-susceptible3 alleles as well as a gain-of-function mutant of CALMODULIN-BINDING TRANSCRIPTION ACTIVATOR3 designated camta3-3D. Like transgenic plants overexpressing CAMTA3, camta3-3D mutant plants exhibit compromised SAR and enhanced susceptibility to virulent pathogens, suggesting that CAMTA3 is a critical regulator of both basal resistance and SAR.
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116
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Behringer C, Bartsch K, Schaller A. Safeners recruit multiple signalling pathways for the orchestrated induction of the cellular xenobiotic detoxification machinery in Arabidopsis. PLANT, CELL & ENVIRONMENT 2011; 34:1970-85. [PMID: 21726238 DOI: 10.1111/j.1365-3040.2011.02392.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Safeners enhance herbicide tolerance in crop plants but not in target weeds, thus improving herbicide selectivity. The safeners isoxadifen-ethyl and mefenpyr-diethyl protect cereal crops from sulfonyl urea herbicides in postemergence application. The two safeners were shown here to induce the cellular xenobiotic detoxification machinery in Arabidopsis thaliana when applied to leaves in a way mimicking field application. Gene expression profiling revealed the induction of 446 genes potentially involved in the detoxification process. Transgenic Arabidopsis plants expressing a reporter gene under control of a safener-responsive maize promoter were used as a model system to study the safener signalling pathway. Reporter gene analysis in the tga2/3/5/6, sid2-2 and npr1 mutants as compared with the wild-type background showed that safener inducibility required TGA transcription factors and salicylic acid (SA) in a NON-EXPRESSOR of PR-1 (NPR1)-independent pathway converging on two as-1 promoter elements. For the majority of the safener-responsive Arabidopsis genes, a similar dependence on TGA transcription factors and/or SA was shown by gene expression profiling in wild-type plants as compared with the tga2/3/5/6 and sid2-2 mutants. Thirty-eight percent of the genes, however, were induced by safeners in a TGA/SA-independent manner. These genes are likely to be controlled by WRKY transcription factors and cognate W-boxes in their promoters.
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Affiliation(s)
- Carina Behringer
- Institute of Plant Physiology and Biotechnology, University of Hohenheim, D-70599 Stuttgart, Germany
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117
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Dobón A, Canet JV, Perales L, Tornero P. Quantitative genetic analysis of salicylic acid perception in Arabidopsis. PLANTA 2011; 234:671-84. [PMID: 21614499 DOI: 10.1007/s00425-011-1436-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 05/08/2011] [Indexed: 05/10/2023]
Abstract
Salicylic acid (SA) is a phytohormone required for a full resistance against some pathogens in Arabidopsis, and NPR1 (Non-Expressor of Pathogenesis Related Genes 1) is the only gene with a strong effect on resistance induced by SA which has been described. There can be additional components of SA perception that escape the traditional approach of mutagenesis. An alternative to that approach is searching in the natural variation of Arabidopsis. Different methods of analyzing the variation between ecotypes have been tried and it has been found that measuring the growth of a virulent isolate of Pseudomonas syringae after the exogenous application of SA is the most effective one. Two ecotypes, Edi-0 and Stw-0, have been crossed, and their F2 has been studied. There are two significant quantitative trait loci (QTLs) in this population, and there is one QTL in each one of the existing mapping populations Col-4 × Laer-0 and Laer-0 × No-0. They have different characteristics: while one QTL is only detectable at low concentrations of SA, the other acts after the point of crosstalk with methyl jasmonate signalling. Three of the QTLs have candidates described in SA perception as NPR1, its interactors, and a calmodulin binding protein.
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Affiliation(s)
- Albor Dobón
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas; Ciudad Politécnica de Innovación, Ed. 8E; C/Ingeniero Fausto Elio s/n, 46022, Valencia, Spain
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118
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Contreras-Cornejo HA, Macías-Rodríguez L, Beltrán-Peña E, Herrera-Estrella A, López-Bucio J. Trichoderma-induced plant immunity likely involves both hormonal- and camalexin-dependent mechanisms in Arabidopsis thaliana and confers resistance against necrotrophic fungi Botrytis cinerea. PLANT SIGNALING & BEHAVIOR 2011; 6:1554-63. [PMID: 21931272 PMCID: PMC3256384 DOI: 10.4161/psb.6.10.17443] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Filamentous fungi belonging to the genus Trichoderma have long been recognized as agents for the biocontrol of plant diseases. In this work, we investigated the mechanisms involved in the defense responses of Arabidopsis thaliana seedlings elicited by co-culture with Trichoderma virens and Trichoderma atroviride. Interaction of plant roots with fungal mycelium induced growth and defense responses, indicating that both processes are not inherently antagonist. Expression studies of the pathogenesis-related reporter markers pPr1a:uidA and pLox2:uidA in response to T. virens or T. atroviride provided evidence that the defense signaling pathway activated by these fungi involves salicylic acid (SA) and/or jasmonic acid (JA) depending on the amount of conidia inoculated. Moreover, we found that Arabidopsis seedlings colonized by Trichoderma accumulated hydrogen peroxide and camalexin in leaves. When grown under axenic conditions, T. virens produced indole-3-carboxaldehyde (ICAld) a tryptophan-derived compound with activity in plant development. In Arabidopsis seedlings whose roots are in contact with T. virens or T. atroviride, and challenged with Botrytis cinerea in leaves, disease severity was significantly reduced compared to axenically grown seedlings. Our results indicate that the defense responses elicited by Trichoderma in Arabidopsis are complex and involve the canonical defense hormones SA and JA as well as camalexin, which may be important factors in boosting plant immunity.
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Affiliation(s)
- Hexon Angel Contreras-Cornejo
- Instituto de Investigaciones Químico-Biológicas; Universidad Michoacana de San Nicolás de Hidalgo; Morelia, Michoacán México
| | - Lourdes Macías-Rodríguez
- Instituto de Investigaciones Químico-Biológicas; Universidad Michoacana de San Nicolás de Hidalgo; Morelia, Michoacán México
| | - Elda Beltrán-Peña
- Instituto de Investigaciones Químico-Biológicas; Universidad Michoacana de San Nicolás de Hidalgo; Morelia, Michoacán México
| | - Alfredo Herrera-Estrella
- Laboratorio Nacional de Genómica para la Biodiversidad; CINVESTAV Irapuato; Irapuato, Guanajuato México
| | - José López-Bucio
- Instituto de Investigaciones Químico-Biológicas; Universidad Michoacana de San Nicolás de Hidalgo; Morelia, Michoacán México
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119
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Abstract
Properly coordinated defense signaling networks are critical for the fitness of plants. One hub of the defense networks is centered on salicylic acid (SA), which plays a key role in activating disease resistance in plants. However, while a number of genes are known to affect SA-mediated defense, relatively little is known about how these gene interact genetically with each other. Here we exploited the unique defense-sensitized Arabidopsis mutant accelerated cell death (acd) 6-1 to dissect functional relationships among key components in the SA hub. We show that while enhanced disease susceptibility (eds) 1-2 and phytoalexin deficient (pad) 4-1 suppressed acd6-1-conferred small size, cell death, and defense phenotypes, a combination of these two mutations did not incur additive suppression. This suggests that EDS1 and PAD4 act in the same signaling pathway. To further evaluate genetic interactions among SA regulators, we constructed 10 pairwise crosses in the acd6-1 background among mutants defective in: SA INDUCTION-DEFICIENT 2 for SA biosynthesis; AGD2-LIKE DEFENSE 1, EDS5, and PAD4 for SA accumulation; and NONEXPRESSOR OF PR GENES 1 for SA signaling. Systematic analysis of the triple mutants based on their suppression of acd6-1-conferred phenotypes revealed complex and interactive genetic relationships among the tested SA genes. Our results suggest a more comprehensive view of the gene networks governing SA function and provide a framework for further interrogation of the important roles of SA and possibly other signaling molecules in regulating plant disease resistance.
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120
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Le Henanff G, Farine S, Kieffer-Mazet F, Miclot AS, Heitz T, Mestre P, Bertsch C, Chong J. Vitis vinifera VvNPR1.1 is the functional ortholog of AtNPR1 and its overexpression in grapevine triggers constitutive activation of PR genes and enhanced resistance to powdery mildew. PLANTA 2011; 234:405-17. [PMID: 21505863 DOI: 10.1007/s00425-011-1412-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Accepted: 03/31/2011] [Indexed: 05/08/2023]
Abstract
Studying grapevine (Vitis vinifera) innate defense mechanisms is a prerequisite to the development of new protection strategies, based on the stimulation of plant signaling pathways to trigger pathogen resistance. Two transcriptional coactivators (VvNPR1.1 and VvNPR1.2) with similarity to Arabidopsis thaliana NPR1 (Non-Expressor of PR genes 1), a well-characterized and key signaling element of the salicylic acid (SA) pathway, were recently isolated in Vitis vinifera. In this study, functional characterization of VvNPR1.1 and VvNPR1.2, including complementation of the Arabidopsis npr1 mutant, revealed that VvNPR1.1 is a functional ortholog of AtNPR1, whereas VvNPR1.2 likely has a different function. Ectopic overexpression of VvNPR1.1 in the Arabidopsis npr1-2 mutant restored plant growth at a high SA concentration, Pathogenesis Related 1 (PR1) gene expression after treatment with SA or bacterial inoculation, and resistance to virulent Pseudomonas syringae pv. maculicola bacteria. Moreover, stable overexpression of VvNPR1.1-GFP in V. vinifera resulted in constitutive nuclear localization of the fusion protein and enhanced PR gene expression in uninfected plants. Furthermore, grapevine plants overexpressing VvNPR1.1-GFP exhibited an enhanced resistance to powdery mildew infection. This work highlights the importance of the conserved SA/NPR1 signaling pathway for resistance to biotrophic pathogens in V. vinifera.
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Affiliation(s)
- Gaëlle Le Henanff
- Université de Haute Alsace, Laboratoire Vigne, Biotechnologies et Environnement (EA3991), 33 rue de Herrlisheim, 68000, Colmar, France
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121
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Xiao S, Chye ML. Overexpression of Arabidopsis ACBP3 enhances NPR1-dependent plant resistance to Pseudomonas syringe pv tomato DC3000. PLANT PHYSIOLOGY 2011; 156:2069-81. [PMID: 21670223 PMCID: PMC3149925 DOI: 10.1104/pp.111.176933] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 06/10/2011] [Indexed: 05/18/2023]
Abstract
ACBP3 is one of six Arabidopsis (Arabidopsis thaliana) genes, designated ACBP1 to ACBP6, that encode acyl-coenzyme A (CoA)-binding proteins (ACBPs). These ACBPs bind long-chain acyl-CoA esters and phospholipids and are involved in diverse cellular functions, including acyl-CoA homeostasis, development, and stress tolerance. Recombinant ACBP3 binds polyunsaturated acyl-CoA esters and phospholipids in vitro. Here, we show that ACBP3 plays a role in the plant defense response to the bacterial pathogen Pseudomonas syringae pv tomato DC3000. ACBP3 mRNA was up-regulated upon pathogen infection and treatments using pathogen elicitors and defense-related phytohormones. Transgenic Arabidopsis ACBP3 overexpressors (ACBP3-OEs) showed constitutive expression of pathogenesis-related genes (PR1, PR2, and PR5), cell death, and hydrogen peroxide accumulation in leaves. Consequently, ACBP3-OEs displayed enhanced resistance to the bacterial pathogen P. syringae DC3000. In contrast, the acbp3 T-DNA insertional mutant was more susceptible and exhibited lower PR gene transcript levels upon infection. Using the ACBP3 OE-1 line in combination with nonexpressor of PR genes1 (npr1-5) or coronatine-insensitive1 (coi1-2), we concluded that the enhanced PR gene expression and P. syringae DC3000 resistance in the ACBP3-OEs are dependent on the NPR1-mediated, but not the COI1-mediated, signaling pathway. Given that ACBP3-OEs showed greater susceptibility to infection by the necrotrophic fungus Botrytis cinerea while the acbp3 mutant was less susceptible, we suggest that ACBP3 plays a role in the plant defense response against biotrophic pathogens that is distinct from necrotrophic pathogens. ACBP3 function in plant defense was supported further by bioinformatics data showing up-regulation of many biotic and abiotic stress-related genes in ACBP3 OE-1 in comparison with the wild type.
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Affiliation(s)
| | - Mee-Len Chye
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China
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122
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Wang GF, Seabolt S, Hamdoun S, Ng G, Park J, Lu H. Multiple roles of WIN3 in regulating disease resistance, cell death, and flowering time in Arabidopsis. PLANT PHYSIOLOGY 2011; 156:1508-19. [PMID: 21543726 PMCID: PMC3135961 DOI: 10.1104/pp.111.176776] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Accepted: 04/26/2011] [Indexed: 05/18/2023]
Abstract
The salicylic acid (SA) regulatory gene HOPW1-1-INTERACTING3 (WIN3) was previously shown to confer resistance to the biotrophic pathogen Pseudomonas syringae. Here, we report that WIN3 controls broad-spectrum disease resistance to the necrotrophic pathogen Botrytis cinerea and contributes to basal defense induced by flg22, a 22-amino acid peptide derived from the conserved region of bacterial flagellin proteins. Genetic analysis indicates that WIN3 acts additively with several known SA regulators, including PHYTOALEXIN DEFICIENT4, NONEXPRESSOR OF PR GENES1 (NPR1), and SA INDUCTION-DEFICIENT2, in regulating SA accumulation, cell death, and/or disease resistance in the Arabidopsis (Arabidopsis thaliana) mutant acd6-1. Interestingly, expression of WIN3 is also dependent on these SA regulators and can be activated by cell death, suggesting that WIN3-mediated signaling is interconnected with those derived from other SA regulators and cell death. Surprisingly, we found that WIN3 and NPR1 synergistically affect flowering time via influencing the expression of flowering regulatory genes FLOWERING LOCUS C and FLOWERING LOCUS T. Taken together, our data reveal that WIN3 represents a novel node in the SA signaling networks to regulate plant defense and flowering time. They also highlight that plant innate immunity and development are closely connected processes, precise regulation of which should be important for the fitness of plants.
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Affiliation(s)
| | | | | | | | | | - Hua Lu
- Corresponding author; e-mail
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123
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Tang J, Zhu X, Wang Y, Liu L, Xu B, Li F, Fang J, Chu C. Semi-dominant mutations in the CC-NB-LRR-type R gene, NLS1, lead to constitutive activation of defense responses in rice. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 66:996-1007. [PMID: 21418352 DOI: 10.1111/j.1365-313x.2011.04557.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In this study, we characterized the semi-dominant mutant nls1-1D (necrotic leaf sheath 1) of rice, which displays spontaneous lesions, specifically on leaf sheaths, with a developmental pattern. nls1-1D plants also exhibited constitutively activated defense responses, including extensive cell death, excess hydrogen peroxide and salicylic acid (SA) accumulation, up-regulated expressions of pathogenesis-related genes, and enhanced resistance to bacterial pathogens. Map-based cloning revealed that NLS1 encodes a typical CC-NB-LRR-type protein in rice. The nls1-1D mutation causes a S367N substitution in the non-conserved region close to the GLPL motif of the NB domain. An adjacent S366T substitution was found in another semi-dominant mutant, nls1-2D, which exhibited the same phenotypes as nls1-1D. Combined analyses of wild-type plants transformed with the mutant NLS1 gene (nls1-1D), NLS1 RNAi and over-expression transgenic lines showed that nls1-2D is allelic to nls1-1D, and both mutations may cause constitutive auto-activation of the NLS1 R protein. Further real-time PCR analysis revealed that NLS1 is expressed constitutively in an age-dependent manner. In addition, because the morphology and constitutive defense responses of nls1-1D were not suppressed by blocking SA or NPR1 transcript accumulation, we suggest that NLS1 mediates both SA and NPR1-independent defense signaling pathways in rice.
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Affiliation(s)
- Jiuyou Tang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
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124
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Abstract
The small phenolic compound salicylic acid (SA) plays an important regulatory role in multiple physiological processes including plant immune response. Significant progress has been made during the past two decades in understanding the SA-mediated defense signaling network. Characterization of a number of genes functioning in SA biosynthesis, conjugation, accumulation, signaling, and crosstalk with other hormones such as jasmonic acid, ethylene, abscisic acid, auxin, gibberellic acid, cytokinin, brassinosteroid, and peptide hormones has sketched the finely tuned immune response network. Full understanding of the mechanism of plant immunity will need to take advantage of fast developing genomics tools and bioinformatics techniques. However, elucidating genetic components involved in these pathways by conventional genetics, biochemistry, and molecular biology approaches will continue to be a major task of the community. High-throughput method for SA quantification holds the potential for isolating additional mutants related to SA-mediated defense signaling.
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Affiliation(s)
- Chuanfu An
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
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125
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Wang GY, Shi JL, Ng G, Battle SL, Zhang C, Lu H. Circadian clock-regulated phosphate transporter PHT4;1 plays an important role in Arabidopsis defense. MOLECULAR PLANT 2011; 4:516-26. [PMID: 21447757 PMCID: PMC3988428 DOI: 10.1093/mp/ssr016] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2010] [Accepted: 02/10/2011] [Indexed: 05/18/2023]
Abstract
The Arabidopsis accelerated cell death 6-1 (acd6-1) mutant shows constitutive defense, cell death, and extreme dwarf phenotypes. In a screen for acd6-1 suppressors, we identified a mutant that was disrupted by a T-DNA in the PHOSPHATE TRANSPORTER 4;1 (PHT4;1) gene. The suppressor mutant pht4;1-1 is dominant, expresses truncated PHT4;1 transcripts, and is more susceptible to virulent Pseudomonas syringae strains but not to several avirulent strains. Treatment with a salicylic acid (SA) agonist induced a similar level of resistance in Col-0 and pht4;1-1, suggesting that PHT4;1 acts upstream of the SA pathway. Genetic analysis further indicates that PHT4;1 contributes to SID2-dependent and -independent pathways. Transgenic expression of the DNA fragment containing the PHT4;1-1 region or the full-length PHT4;1 gene in wild-type conferred enhanced susceptibility to Pseudomonas infection. Interestingly, expression of PHT4;1 is regulated by the circadian clock. Together, these data suggest that the phosphate transporter PHT4;1 is critical for basal defense and also implicate a potential role of the circadian clock in regulating innate immunity of Arabidopsis.
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Affiliation(s)
| | | | | | | | | | - Hua Lu
- Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
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126
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Ghanta S, Bhattacharyya D, Sinha R, Banerjee A, Chattopadhyay S. Nicotiana tabacum overexpressing γ-ECS exhibits biotic stress tolerance likely through NPR1-dependent salicylic acid-mediated pathway. PLANTA 2011; 233:895-910. [PMID: 21234598 DOI: 10.1007/s00425-011-1349-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 01/04/2011] [Indexed: 05/09/2023]
Abstract
The elaborate networks and the crosstalk of established signaling molecules like salicylic acid (SA), jasmonic acid (JA), ethylene (ET), abscisic acid (ABA), reactive oxygen species (ROS) and glutathione (GSH) play key role in plant defense response. To obtain further insight into the mechanism through which GSH is involved in this crosstalk to mitigate biotic stress, transgenic Nicotiana tabacum overexpressing Lycopersicon esculentum gamma-glutamylcysteine synthetase (LeECS) gene (NtGB lines) were generated with enhanced level of GSH in comparison with wild-type plants exhibiting resistance to pathogenesis as well. The expression levels of non-expressor of pathogenesis-related genes 1 (NPR1)-dependent genes like pathogenesis-related gene 1 (NtPR1), mitogen-activated protein kinase kinase (NtMAPKK), glutamine synthetase (NtGLS) were significantly enhanced along with NtNPR1. However, the expression levels of NPR1-independent genes like NtPR2, NtPR5 and short-chain dehydrogenase/reductase family protein (NtSDRLP) were either insignificant or were downregulated. Additionally, increase in expression of thioredoxin (NtTRXh), S-nitrosoglutathione reductase 1 (NtGSNOR1) and suppression of isochorismate synthase 1 (NtICS1) was noted. Comprehensive analysis of GSH-fed tobacco BY2 cell line in a time-dependent manner reciprocated the in planta results. Better tolerance of NtGB lines against biotrophic Pseudomonas syringae pv. tabaci was noted as compared to necrotrophic Alternaria alternata. Through two-dimensional gel electrophoresis (2-DE) and image analysis, 48 differentially expressed spots were identified and through identification as well as functional categorization, ten proteins were found to be SA-related. Collectively, our results suggest GSH to be a member in cross-communication with other signaling molecules in mitigating biotic stress likely through NPR1-dependent SA-mediated pathway.
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Affiliation(s)
- Srijani Ghanta
- Plant Biotechnology Laboratory, Drug Development/Diagnostics and Biotechnology Division, Indian Institute of Chemical Biology (A unit of Council of Scientific and Industrial Research), 4, Raja S. C. Mullick Road, Kolkata 700-032, India
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Cecchini NM, Monteoliva MI, Alvarez ME. Proline dehydrogenase contributes to pathogen defense in Arabidopsis. PLANT PHYSIOLOGY 2011; 155:1947-59. [PMID: 21311034 PMCID: PMC3091113 DOI: 10.1104/pp.110.167163] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 02/03/2011] [Indexed: 05/19/2023]
Abstract
L-proline (Pro) catabolism is activated in plants recovering from abiotic stresses associated with water deprivation. In this catabolic pathway, Pro is converted to glutamate by two reactions catalyzed by proline dehydrogenase (ProDH) and Δ(1)-pyrroline-5-carboxylate dehydrogenase (P5CDH), with Δ(1)-pyrroline-5-carboxylate (P5C) as the intermediate. Alternatively, under certain conditions, the P5C derived from Pro is converted back to Pro by P5C reductase, thus stimulating the Pro-P5C cycle, which may generate reactive oxygen species (ROS) as a consequence of the ProDH activity. We previously observed that Pro biosynthesis is altered in Arabidopsis (Arabidopsis thaliana) tissues that induce the hypersensitive response (HR) in response to Pseudomonas syringae. In this work, we characterized the Pro catabolic pathway and ProDH activity in this model. Induction of ProDH expression was found to be dependent on salicylic acid, and an increase in ProDH activity was detected in cells destined to die. To evaluate the role of ProDH in the HR, ProDH-silenced plants were generated. These plants displayed reduced ROS and cell death levels as well as enhanced susceptibility in response to avirulent pathogens. Interestingly, the early activation of ProDH was accompanied by an increase in P5C reductase but not in P5CDH transcripts, with few changes occurring in the Pro and P5C levels. Therefore, our results suggest that in wild-type plants, ProDH is a defense component contributing to HR and disease resistance, which apparently potentiates the accumulation of ROS. The participation of the Pro-P5C cycle in the latter response is discussed.
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Bai W, Chern M, Ruan D, Canlas PE, Sze-To WH, Ronald PC. Enhanced disease resistance and hypersensitivity to BTH by introduction of an NH1/OsNPR1 paralog. PLANT BIOTECHNOLOGY JOURNAL 2011; 9:205-15. [PMID: 20561248 DOI: 10.1111/j.1467-7652.2010.00544.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Non-expresser of pathogenesis-related genes 1 (NPR1) is the master regulator of salicylic acid-mediated systemic acquired resistance. Over-expression of Arabidopsis NPR1 and rice NH1 (NPR1 homolog1)/OsNPR1 in rice results in enhanced resistance. While there are four rice NPR1 paralogs in the rice genome, none have been demonstrated to function in disease resistance. To study rice NPR1 paralog 3, we introduced constructs into rice and tested for effects on resistance to infection by Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of bacterial blight. While over-expression of NH3 using the maize ubiquitin-1 promoter failed to enhance resistance, introduction of an extra copy of NH3 driven by its own promoter (nNT-NH3) resulted in clear, enhanced resistance. Progeny analysis confirms that the enhanced resistance phenotype, measured by Xoo-induced lesion length, is associated with the NH3 transgene. Bacterial growth curve analysis indicates that bacterial population levels are reduced 10-fold in nNT-NH3 lines compared to control rice lines. The transgenic plants exhibit higher sensitivity to benzothiadiazole (BTH) and 2,6-dichloroisonicotinic acid (INA) treatment as measured by increased cell death. Expression analysis of pathogenesis-related (PR) genes showed that nNT-NH3 plants display greatly enhanced induction of PR genes only after treatment with BTH. Our study demonstrates an alternative method to employ a regulatory protein to enhance plant defence. This approach avoids using undesirable constitutive, high-level expression and may prove to be more practical for engineering resistance.
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Affiliation(s)
- Wei Bai
- Department of Plant Pathology, University of California, Davis, CA, USA
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Maier F, Zwicker S, Hückelhoven A, Meissner M, Funk J, Pfitzner AJP, Pfitzner UM. NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 (NPR1) and some NPR1-related proteins are sensitive to salicylic acid. MOLECULAR PLANT PATHOLOGY 2011; 12:73-91. [PMID: 21118350 PMCID: PMC6640455 DOI: 10.1111/j.1364-3703.2010.00653.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 (NPR1; also known as NIM1) is a master regulator of systemic acquired resistance (SAR). SAR is induced by salicylic acid (SA), leading to the expression of PATHOGENESIS-RELATED (PR) genes. Current evidence suggests that NPR1 is part of a transcription complex tethered to activation sequence-1 (as-1)-like cis-acting elements in PR-1 gene promoters through TGA transcription factors, and that SA-dependent PR-1 gene expression is regulated by NIM1-INTERACTING (NIMIN) proteins. In Arabidopsis, NPR1 is active only after SA induction. Regulation of Arabidopsis NPR1 activity has been proposed to comprise cysteine-156 (Cys-156), mediating SA-induced cytoplasmic oligomer-nuclear monomer exchange, and Cys-521 and Cys-529, mediating SA-dependent transcriptional activation. Tobacco NPR1 does not harbour these residues. To understand the function of tobacco NPR1, we analysed its biochemical capabilities in a heterologous system: yeast. Tobacco NPR1 differs from Arabidopsis NPR1 in its subcellular localization and its transactivation potential. Yet, both tobacco and Arabidopsis NPR1, as well as tobacco NIM1-like1, alter some of their biochemical activities in response to SA. Whereas the addition of SA to yeast growth medium induces transcriptional activity in tobacco NPR1, its interaction with NIMIN2-type proteins is suppressed. The effects of SA are specific, sensitive and occur coordinately. They are abolished completely by mutation of the arginine residue within the invariable penta-amino acid motif LENRV, as present in the nonfunctional Arabidopsis nim1-4 allele. Furthermore, NPR1 proteins with the LENRV domain coincidently harbour a broad and strongly conserved NIMIN1/NIMIN2 binding site. Our data suggest that NPR1 and some NPR1-like proteins are sensitive to the plant hormone SA, altering some of their biochemical capabilities to enable stimulus-dependent gene expression. The sensitivity of NPR1 proteins to SA, together with their differential interaction with diverse NIMIN proteins, seems a plausible molecular basis for the timely and coordinated activation of PR genes during SAR.
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Affiliation(s)
- Felix Maier
- Institut für Genetik, Universität Hohenheim, FG Allgemeine Virologie, D-70593 Stuttgart, Germany
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130
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Sugano S, Jiang CJ, Miyazawa SI, Masumoto C, Yazawa K, Hayashi N, Shimono M, Nakayama A, Miyao M, Takatsuji H. Role of OsNPR1 in rice defense program as revealed by genome-wide expression analysis. PLANT MOLECULAR BIOLOGY 2010; 74:549-62. [PMID: 20924648 DOI: 10.1007/s11103-010-9695-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 09/21/2010] [Indexed: 05/04/2023]
Abstract
NPR1 is a central regulator of salicylic-acid (SA)-mediated defense signaling in Arabidopsis. Here, we report the characterization of OsNPR1, an Oryzae sativa (rice) ortholog of NPR1, focusing on its role in blast disease resistance and identification of OsNPR1-regulated genes. Blast resistance tests using OsNPR1 knockdown and overexpressing rice lines demonstrated the essential role of OsNPR1 in benzothiadiazole (BTH)-induced blast resistance. Genome-wide transcript profiling using OsNPR1-knockdown lines revealed that 358 genes out of 1,228 BTH-upregulated genes and 724 genes out of 1,069 BTH-downregulated genes were OsNPR1-dependent with respect to BTH responsiveness, thereby indicating that OsNPR1 plays a more vital role in gene downregulation. The OsNPR1-dependently downregulated genes included many of those involved in photosynthesis and in chloroplast translation and transcription. Reduction of photosynthetic activity after BTH treatment and its negation by OsNPR1 knockdown were indeed reflected in the changes in Fv/Fm values in leaves. These results imply the role of OsNPR1 in the reallocation of energy and resources during defense responses. We also examined the OsNPR1-dependence of SA-mediated suppression of ABA-induced genes.
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Affiliation(s)
- Shoji Sugano
- Plant Disease Resistance Research Unit, Division of Plant Sciences, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602, Japan
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Shi Z, Maximova SN, Liu Y, Verica J, Guiltinan MJ. Functional analysis of the Theobroma cacao NPR1 gene in Arabidopsis. BMC PLANT BIOLOGY 2010; 10:248. [PMID: 21078185 PMCID: PMC3095330 DOI: 10.1186/1471-2229-10-248] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Accepted: 11/15/2010] [Indexed: 05/05/2023]
Abstract
BACKGROUND The Arabidopsis thaliana NPR1 gene encodes a transcription coactivator (NPR1) that plays a major role in the mechanisms regulating plant defense response. After pathogen infection and in response to salicylic acid (SA) accumulation, NPR1 translocates from the cytoplasm into the nucleus where it interacts with other transcription factors resulting in increased expression of over 2000 plant defense genes contributing to a pathogen resistance response. RESULTS A putative Theobroma cacao NPR1 cDNA was isolated by RT-PCR using degenerate primers based on homologous sequences from Brassica, Arabidopsis and Carica papaya. The cDNA was used to isolate a genomic clone from Theobroma cacao containing a putative TcNPR1 gene. DNA sequencing revealed the presence of a 4.5 kb coding region containing three introns and encoding a polypeptide of 591 amino acids. The predicted TcNPR1 protein shares 55% identity and 78% similarity to Arabidopsis NPR1, and contains each of the highly conserved functional domains indicative of this class of transcription factors (BTB/POZ and ankyrin repeat protein-protein interaction domains and a nuclear localization sequence (NLS)). To functionally define the TcNPR1 gene, we transferred TcNPR1 into an Arabidopsis npr1 mutant that is highly susceptible to infection by the plant pathogen Pseudomonas syringae pv. tomato DC3000. Driven by the constitutive CaMV35S promoter, the cacao TcNPR1 gene partially complemented the npr1 mutation in transgenic Arabidopsis plants, resulting in 100 fold less bacterial growth in a leaf infection assay. Upon induction with SA, TcNPR1 was shown to translocate into the nucleus of leaf and root cells in a manner identical to Arabidopsis NPR1. Cacao NPR1 was also capable of participating in SA-JA signaling crosstalk, as evidenced by the suppression of JA responsive gene expression in TcNPR1 overexpressing transgenic plants. CONCLUSION Our data indicate that the TcNPR1 is a functional ortholog of Arabidopsis NPR1, and is likely to play a major role in defense response in cacao. This fundamental knowledge can contribute to breeding of disease resistant cacao varieties through the application of molecular markers or the use of transgenic strategies.
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Affiliation(s)
- Zi Shi
- Huck Institute of Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Siela N Maximova
- The Department of Horticulture, The Pennsylvania State University, University Park, PA 16802, USA
| | - Yi Liu
- Huck Institute of Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Joseph Verica
- The Department of Horticulture, The Pennsylvania State University, University Park, PA 16802, USA
| | - Mark J Guiltinan
- Huck Institute of Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
- The Department of Horticulture, The Pennsylvania State University, University Park, PA 16802, USA
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132
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Canet JV, Dobón A, Roig A, Tornero P. Structure-function analysis of npr1 alleles in Arabidopsis reveals a role for its paralogs in the perception of salicylic acid. PLANT, CELL & ENVIRONMENT 2010; 33:1911-22. [PMID: 20561252 DOI: 10.1111/j.1365-3040.2010.02194.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Salicylic acid (SA) is necessary for plant defence against some pathogens, whereas NPR1 is necessary for SA perception. Plant defence can be induced to an extreme by several applications of benzothiadiazole (BTH), an analogue of SA. Thus, plants that do not perceive BTH grow unaffected, whereas wild-type plants grow stunted. This feature allows us to screen for mutants in Arabidopsis thaliana that show insensitivity to BTH in a high-throughput fashion. Most of the mutants are npr1 alleles, with similar phenotypes in plant weight and pathogen growth. The mutations are clustered in the carboxyl-terminal part of the protein, and no obvious null alleles were recovered. These facts have prompted a search for knockouts in the NPR1 gene. Two of these KO alleles identified are null and have an intermediate phenotype. All the evidence presented lead us to propose a redundancy in SA perception, with the paralogs of NPR1 taking part in this signalling. We show that the mutations recovered in the screening genetically interact with the paralogs preventing their function in SA signalling.
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Affiliation(s)
- Juan Vicente Canet
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia (UPV)-Consejo Superior de Investigaciones Científicas (CSIC), Ciudad Politécnica de la Innovación (CPI), Ed. 8E C/ Ingeniero Fausto Elio s/n, 46022 Valencia, Spain
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133
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DeFraia CT, Zhang X, Mou Z. Elongator subunit 2 is an accelerator of immune responses in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 64:511-23. [PMID: 20807211 DOI: 10.1111/j.1365-313x.2010.04345.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Immune responses in eukaryotes involve rapid and profound transcriptional reprogramming. Although mechanisms regulating the amplitude of defense gene expression have been extensively characterized, those controlling the speed of defense gene induction are not well understood. Here, we show that the Arabidopsis Elongator subunit 2 (AtELP2) regulates the kinetics of defense gene induction. AtELP2 is required for rapid defense gene induction and the establishment of full basal and effector-triggered immunity (ETI). Surprisingly, biological or chemical induction of systemic acquired resistance (SAR), a long-lasting plant immunity against a broad spectrum of pathogens, restores pathogen resistance to Atelp2 mutant plants. Simultaneous removal of AtELP2 and NPR1, a transcription coactivator essential for full-scale expression of a subset of defense genes and the establishment of SAR, completely abolishes resistance to two different ETI-inducing pathogens. These results demonstrate that AtELP2 is an accelerator of defense gene induction, which functions largely independently of NPR1 in establishing plant immunity.
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Affiliation(s)
- Christopher T DeFraia
- Department of Microbiology and Cell Science, University of Florida, PO Box 110700, Gainesville, FL 32611, USA
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134
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Marek G, Carver R, Ding Y, Sathyanarayan D, Zhang X, Mou Z. A high-throughput method for isolation of salicylic acid metabolic mutants. PLANT METHODS 2010; 6:21. [PMID: 20863393 PMCID: PMC2949671 DOI: 10.1186/1746-4811-6-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 09/23/2010] [Indexed: 05/03/2023]
Abstract
BACKGROUND Salicylic acid (SA) is a key defense signal molecule against biotrophic pathogens in plants. Quantification of SA levels in plants is critical for dissecting the SA-mediated immune response. Although HPLC and GC/MS are routinely used to determine SA concentrations, they are expensive and time-consuming. We recently described a rapid method for a bacterial biosensor Acinetobacter sp. ADPWH_lux-based SA quantification, which enables high-throughput analysis. In this study we describe an improved method for fast sample preparation, and present a high-throughput strategy for isolation of SA metabolic mutants. RESULTS On the basis of the previously described biosensor-based method, we simplified the tissue collection and the SA extraction procedure. Leaf discs were collected and boiled in Luria-Bertani (LB), and then the released SA was measured with the biosensor. The time-consuming steps of weighing samples, grinding tissues and centrifugation were avoided. The direct boiling protocol detected similar differences in SA levels among pathogen-infected wild-type, npr1 (nonexpressor of pathogenesis-related genes), and sid2 (SA induction-deficient) plants as did the previously described biosensor-based method and an HPLC-based approach, demonstrating the efficacy of the protocol presented here. We adapted this protocol to a high-throughput format and identified six npr1 suppressors that accumulated lower levels of SA than npr1 upon pathogen infection. Two of the suppressors were found to be allelic to the previously identified eds5 mutant. The other four are more susceptible than npr1 to the bacterial pathogen Pseudomonas syringae pv. maculicola ES4326 and their identity merits further investigation. CONCLUSIONS The rapid SA extraction method by direct boiling of leaf discs further reduced the cost and time required for the biosensor Acinetobacter sp. ADPWH_lux-based SA estimation, and allowed the screening for npr1 suppressors that accumulated less SA than npr1 after pathogen infection in a high-throughput manner. The highly efficacious SA estimation protocol can be applied in genetic screen for SA metabolic mutants and characterization of enzymes involved in SA metabolism. The mutants isolated in this study may help identify new components in the SA-related signaling pathways.
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Affiliation(s)
- George Marek
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL, 32611, USA
| | - Ryan Carver
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL, 32611, USA
| | - Yezhang Ding
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL, 32611, USA
| | - Deepak Sathyanarayan
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL, 32611, USA
| | - Xudong Zhang
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL, 32611, USA
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL, 32611, USA
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Makandar R, Nalam V, Chaturvedi R, Jeannotte R, Sparks AA, Shah J. Involvement of salicylate and jasmonate signaling pathways in Arabidopsis interaction with Fusarium graminearum. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2010; 23:861-70. [PMID: 20521949 PMCID: PMC4164197 DOI: 10.1094/mpmi-23-7-0861] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Fusarium graminearum is the principal causative agent of Fusarium head blight (FHB), a devastating disease of wheat and barley. This fungus can also colonize Arabidopsis thaliana. Disease resistance was enhanced in transgenic wheat and Arabidopsis plants that constitutively overexpress the NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1) gene, which regulates salicylic acid (SA) signaling and modulates the activation of jasmonic acid (JA)-dependent defenses. Here, we provide several lines of evidence that reveal an important role for SA and JA signaling in Arabidopsis defense against F. graminearum. SA level was elevated in fungus-inoculated leaves, and SA application and biologically activated systemic acquired resistance enhanced resistance. Furthermore, the disruption of SA accumulation and signaling in the sid2 mutant and NahG transgenic plant, and the npr1 and wrky18 mutants, respectively, resulted in heightened susceptibility to this fungus in leaves and inflorescence. JA signaling was activated in parallel with SA signaling in the fungus-challenged plants. However, the hyperresistance of the JA pathway mutants opr3, coi1, and jar1 indicates that this pathway contributes to susceptibility. Genetic and biochemical experiments indicate that the JA pathway promotes disease by attenuating the activation of SA signaling in fungus-inoculated plants. However, the hypersusceptibility of the jar1 npr1 double mutant compared with the npr1 mutant suggests that JAR1 also contributes to defense, signifying a dichotomous role of JA and a JAR1-dependent mechanism in this interaction.
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Affiliation(s)
- Ragiba Makandar
- Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
- Department of Plant Sciences, University of Hyderabad, Gachibowli, Hyderabad, India
| | - Vamsi Nalam
- Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Ratnesh Chaturvedi
- Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Richard Jeannotte
- Kansas Lipidomics Research Center, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Alexis A. Sparks
- Kansas Lipidomics Research Center, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Jyoti Shah
- Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
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Microarray Detection Call Methodology as a Means to Identify and Compare Transcripts Expressed within Syncytial Cells from Soybean (Glycine max) Roots Undergoing Resistant and Susceptible Reactions to the Soybean Cyst Nematode (Heterodera glycines). J Biomed Biotechnol 2010; 2010:491217. [PMID: 20508855 PMCID: PMC2875038 DOI: 10.1155/2010/491217] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Revised: 09/23/2009] [Accepted: 02/14/2010] [Indexed: 11/27/2022] Open
Abstract
Background. A comparative microarray investigation was done using detection call methodology (DCM) and differential expression analyses. The goal was to identify genes found in specific cell populations that were eliminated by differential expression analysis due to the nature of differential expression methods. Laser capture microdissection (LCM) was used to isolate nearly homogeneous populations of plant root cells. Results. The analyses identified the presence of 13,291 transcripts between the 4 different sample types. The transcripts filtered down into a total of 6,267 that were detected as being present in one or more sample types. A comparative analysis of DCM and differential expression methods showed a group of genes that were not differentially expressed, but were expressed at detectable amounts within specific cell types. Conclusion. The DCM has identified patterns of gene expression not shown by differential expression analyses. DCM has identified genes that are possibly cell-type specific and/or involved in important aspects of plant nematode interactions during the resistance response, revealing the uniqueness of a particular cell population at a particular point during its differentiation process.
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137
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Zhao N, Guan J, Ferrer JL, Engle N, Chern M, Ronald P, Tschaplinski TJ, Chen F. Biosynthesis and emission of insect-induced methyl salicylate and methyl benzoate from rice. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2010; 48:279-87. [PMID: 20199866 DOI: 10.1016/j.plaphy.2010.01.023] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2009] [Revised: 01/24/2010] [Accepted: 01/31/2010] [Indexed: 05/18/2023]
Abstract
Two benzenoid esters, methyl salicylate (MeSA) and methyl benzoate (MeBA), were detected from insect-damaged rice plants. By correlating metabolite production with gene expression analysis, five candidate genes encoding putative carboxyl methyltransferases were identified. Enzymatic assays with Escherichia coli-expressed recombinant proteins demonstrated that only one of the five candidates, OsBSMT1, has salicylic acid (SA) methyltransferase (SAMT) and benzoic acid (BA) methyltransferase (BAMT) activities for producing MeSA and MeBA, respectively. Whereas OsBSMT1 is phylogenetically relatively distant from dicot SAMTs, the three-dimensional structure of OsBSMT1, which was determined using homology-based structural modeling, is highly similar to those of characterized SAMTs. Analyses of OsBSMT1 expression in wild-type rice plants under various stress conditions indicate that the jasmonic acid (JA) signaling pathway plays a critical role in regulating the production and emission of MeSA in rice. Further analysis using transgenic rice plants overexpressing NH1, a key component of the SA signaling pathway in rice, suggests that the SA signaling pathway also plays an important role in governing OsBSMT1 expression and emission of its products, probably through a crosstalk with the JA signaling pathway. The role of the volatile products of OsBSMT1, MeSA and MeBA, in rice defense against insect herbivory is discussed.
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Affiliation(s)
- Nan Zhao
- Department of Plant Sciences, 252 Ellington Plant Sciences Building, University of Tennessee, 2431 Joe Johnson Drive, Knoxville, TN 37996, USA
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138
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Monaghan J, Li X. The HEAT Repeat Protein ILITYHIA is Required for Plant Immunity. ACTA ACUST UNITED AC 2010; 51:742-53. [DOI: 10.1093/pcp/pcq038] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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139
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Mukherjee M, Larrimore KE, Ahmed NJ, Bedick TS, Barghouthi NT, Traw MB, Barth C. Ascorbic acid deficiency in arabidopsis induces constitutive priming that is dependent on hydrogen peroxide, salicylic acid, and the NPR1 gene. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2010; 23:340-51. [PMID: 20121455 DOI: 10.1094/mpmi-23-3-0340] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The ascorbic acid (AA)-deficient Arabidopsis thaliana vtc1-1 mutant exhibits increased resistance to the virulent bacterial pathogen Pseudomonas syringae. This response correlates with heightened levels of salicylic acid (SA), which induces antimicrobial pathogenesis-related (PR) proteins. To determine if SA-mediated, enhanced disease resistance is a general phenomenon of AA deficiency, to elucidate the signal that stimulates SA synthesis, and to identify the biosynthetic pathway through which SA accumulates, we studied the four AA-deficient vtc1-1, vtc2-1, vtc3-1, and vtc4-1 mutants. We also studied double mutants defective in the AA-biosynthetic gene VTC1 and the SA signaling pathway genes PAD4, EDS5, and NPR1, respectively. All vtc mutants were more resistant to P. syringae than the wild type. With the exception of vtc4-1, this correlated with constitutively upregulated H(2)O(2), SA, and messenger RNA levels of PR genes. Double mutants exhibited decreased SA levels and enhanced susceptibility to P. syringae compared with the wild type, suggesting that vtc1-1 requires functional PAD4, EDS5, and NPR1 for SA biosynthesis and pathogen resistance. We suggest that AA deficiency causes constitutive priming through a buildup of H(2)O(2) that stimulates SA accumulation, conferring enhanced disease resistance in vtc1-1, vtc2-1, and vtc3-1, whereas vtc4-1 might be sensitized to H(2)O(2) and SA production after infection.
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Affiliation(s)
- Madhumati Mukherjee
- Department Of Biology, West Virginia University, 53 Campus Drive, Morgantown, USA
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140
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Parkhi V, Kumar V, Campbell LM, Bell AA, Shah J, Rathore KS. Resistance against various fungal pathogens and reniform nematode in transgenic cotton plants expressing Arabidopsis NPR1. Transgenic Res 2010; 19:959-75. [DOI: 10.1007/s11248-010-9374-9] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Accepted: 02/01/2010] [Indexed: 11/28/2022]
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141
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Klink VP, Hosseini P, Matsye PD, Alkharouf NW, Matthews BF. Syncytium gene expression in Glycine max([PI 88788]) roots undergoing a resistant reaction to the parasitic nematode Heterodera glycines. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2010; 48:176-93. [PMID: 20138530 DOI: 10.1016/j.plaphy.2009.12.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 10/31/2009] [Accepted: 12/15/2009] [Indexed: 05/07/2023]
Abstract
The plant parasitic nematode, Heterodera glycines is the major pathogen of Glycine max (soybean). H. glycines accomplish parasitism by creating a nurse cell known as the syncytium from which it feeds. The syncytium undergoes two developmental phases. The first is a parasitism phase where feeding sites are selected, initiating the development of the syncytium. During this earlier phase (1-4 days post infection), syncytia undergoing resistant and susceptible reactions appear the same. The second phase is when the resistance response becomes evident (between 4 and 6dpi) and is completed by 9dpi. Analysis of the resistant reaction of G. max genotype PI 88788 (G. max([PI 88788])) to H. glycines population NL1-RHg/HG-type 7 (H. glycines([NL1-RHg/HG-type 7])) is accomplished by laser microdissection of syncytia at 3, 6 and 9dpi. Comparative analyses are made to pericycle and their neighboring cells isolated from mock-inoculated roots. These analyses reveal induced levels of the jasmonic acid biosynthesis and 13-lipoxygenase pathways. Direct comparative analyses were also made of syncytia at 6 days post infection to those at 3dpi (base line). The comparative analyses were done to identify localized gene expression that characterizes the resistance phase of the resistant reaction. The most highly induced pathways include components of jasmonic acid biosynthesis, 13-lipoxygenase pathway, S-adenosyl methionine pathway, phenylpropanoid biosynthesis, suberin biosynthesis, adenosylmethionine biosynthesis, ethylene biosynthesis from methionine, flavonoid biosynthesis and the methionine salvage pathway. In comparative analyses of 9dpi to 6dpi (base line), these pathways, along with coumarin biosynthesis, cellulose biosynthesis and homogalacturonan degradation are induced. The experiments presented here strongly implicate the jasmonic acid defense pathway as a factor involved in the localized resistant reaction of G. max([PI 88788]) to H. glycines([NL1-RHg/HG-type 7]).
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Affiliation(s)
- Vincent P Klink
- Department of Biological Sciences, Harned Hall, Mississippi State University, Mississippi State, MS, 39762, USA.
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142
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Canet JV, Dobón A, Ibáñez F, Perales L, Tornero P. Resistance and biomass in Arabidopsis: a new model for salicylic acid perception. PLANT BIOTECHNOLOGY JOURNAL 2010; 8:126-41. [PMID: 20040060 DOI: 10.1111/j.1467-7652.2009.00468.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Salicylic acid (SA) is an essential hormone for plant defence and development. SA perception is usually measured by counting the number of pathogens that grow in planta upon an exogenous application of the hormone. A biological SA perception model based on plant fresh weight reduction caused by disease resistance in Arabidopsis thaliana is proposed. This effect is more noticeable when a chemical analogue of SA is used, like Benzothiadiazole (BTH). By spraying BTH several times, a substantial difference in plant biomass is observed when compared with the mock treatment. Such difference is dose-dependent and does not require pathogen inoculation. The model is robust and allows for the comparison of different Arabidopsis ecotypes, recombinant inbreed lines, and mutants. Our results show that two mutants, non-expresser of pathogenesis-related genes 1 (npr1) and auxin resistant 3 (axr3), fail to lose biomass when BTH is applied to them. Further experiments show that axr3 responds to SA and BTH in terms of defence induction. NPR1-related genotypes also confirm the pivotal role of NPR1 in SA perception, and suggest an active program of depletion of resources in the infected tissues.
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Affiliation(s)
- Juan V Canet
- Instituto de Biología Molecular y Celular de Plantas, UPV-CSIC. Avda. de los Naranjos, s/n, Valencia, Spain
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143
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Zhang Y, Shi J, Liu JY, Zhang Y, Zhang JD, Guo XQ. Identification of a novel NPR1-like gene from Nicotiana glutinosa and its role in resistance to fungal, bacterial and viral pathogens. PLANT BIOLOGY (STUTTGART, GERMANY) 2010; 12:23-34. [PMID: 20653885 DOI: 10.1111/j.1438-8677.2009.00210.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The NPR1 or NPR1-like genes play a pivotal role in systemic acquired resistance in plants. Here, we isolated and identified a novel tobacco (Nicotiana glutinosa) NPR1-like gene (designated as NgNPR3). The full-length cDNA is 2049 bp in length with a 1767 bp open reading frame which encodes a 588 amino acids protein with an estimated molecular mass of 66 kDa and a calculated pI of 7.14. Homology analysis suggested that the NgNPR3 protein shares significant similarity to AtNPR3 of Arabidopsis. Transient expression assay of NgNPR3-GFP fusion gene in onion epidermal cells revealed that the NgNPR3 protein was localized to the cytoplasm and moved into the nucleus after redox change. RT-PCR results indicated that NgNPR3 was up-regulated after treatment with SA, INA, H(2)O(2,) and MeJA, which play important roles in various resistance responses in tobacco. Transcriptional level of NgNPR3 was also up-regulated after inoculation with Rhizoctonia solani, Phytophthora parasitica, Alternaria alternata, Pseudomonas solanacearum, and potato virus Y (PVY), respectively. When NgNPR3 was overexpressed in N. tabacum cv. Samsun plants, the transgenic plants showed enhanced resistance to the pathogens A. alternate, P. solanacearum and PVY. Furthermore, NgNPR3-mediated disease resistance is dosage-dependent. Our results suggest that NgNPR3 could be a putative NPR1-like gene, and might play an important role in resistance to a broad range of pathogens in tobacco.
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Affiliation(s)
- Y Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong, China
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144
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Heil M, Ton J. Systemic Resistance Induction by Vascular and Airborne Signaling. PROGRESS IN BOTANY 2010. [DOI: 10.1007/978-3-642-02167-1_11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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145
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Plant Defense Signaling from the Underground Primes Aboveground Defenses to Confer Enhanced Resistance in a Cost-Efficient Manner. PLANT COMMUNICATION FROM AN ECOLOGICAL PERSPECTIVE 2010. [DOI: 10.1007/978-3-642-12162-3_3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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146
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Klink VP, Hosseini P, Matsye P, Alkharouf NW, Matthews BF. A gene expression analysis of syncytia laser microdissected from the roots of the Glycine max (soybean) genotype PI 548402 (Peking) undergoing a resistant reaction after infection by Heterodera glycines (soybean cyst nematode). PLANT MOLECULAR BIOLOGY 2009; 71:525-67. [PMID: 19787434 DOI: 10.1007/s11103-009-9539-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Accepted: 08/09/2009] [Indexed: 05/07/2023]
Abstract
The syncytium is a nurse cell formed within the roots of Glycine max by the plant parasitic nematode Heterodera glycines. Its development and maintenance are essential for nematode survival. The syncytium appears to undergo two developmental phases during its maturation into a functional nurse cell. The first phase is a parasitism phase where the nematode establishes the molecular circuitry that during the second phase ensures a compatible interaction with the plant cell. The cytological features of syncytia undergoing susceptible or resistant reactions appear the same during the parasitism phase. Depending on the outcome of any defense response, the second phase is a period of syncytium maintenance (susceptible reaction) or failure (resistant reaction). In the analyses presented here, the localized gene expression occurring at the syncytium during the resistant reaction was studied. This was accomplished by isolating syncytial cells from Glycine max genotype Peking (PI 548402) by laser capture microdissection. Microarray analyses using the Affymetrix soybean GeneChip directly compared Peking syncytia undergoing a resistant reaction to those undergoing a susceptible reaction during the parasitism phase of the resistant reaction. Those analyses revealed lipoxygenase-9 and lipoxygenase-4 as the most highly induced genes in the resistant reaction. The analysis also identified induced levels of components of the phenylpropanoid pathway. These genes included phenylalanine ammonia lyase, chalcone isomerase, isoflavone reductase, cinnamoyl-CoA reductase and caffeic acid O-methyltransferase. The presence of induced levels of these genes implies the importance of jasmonic acid and phenylpropanoid signaling pathways locally at the site of the syncytium during the resistance phase of the resistant reaction. The analysis also identified highly induced levels of four S-adenosylmethionine synthetase genes, the EARLY-RESPONSIVE TO DEHYDRATION 2 gene and the 14-3-3 gene known as GENERAL REGULATORY FACTOR 2. Subsequent analyses studied microdissected syncytial cells at 3, 6 and 9 days post infection (dpi) during the course of the resistant reaction, resulting in the identification of signature gene expression profiles at each time point in a single G. max genotype, Peking.
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Affiliation(s)
- Vincent P Klink
- Department of Biological Sciences, Mississippi State University, Harned Hall, Mississippi State, MS 39762, USA.
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147
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Wally O, Jayaraj J, Punja ZK. Broad-spectrum disease resistance to necrotrophic and biotrophic pathogens in transgenic carrots (Daucus carota L.) expressing an Arabidopsis NPR1 gene. PLANTA 2009; 231:131-41. [PMID: 19859731 DOI: 10.1007/s00425-009-1031-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Accepted: 09/21/2009] [Indexed: 05/19/2023]
Abstract
The development of transgenic plants highly resistant to a range of pathogens using traditional signal gene expression strategies has been largely ineffective. Modification of systemic acquired resistance (SAR) through the overexpression of a controlling gene such as NPR1 (non-expressor of PR genes) offers an attractive alternative for augmenting the plants innate defense system. The Arabidopsis (At) NPR1 gene was successfully introduced into 'Nantes Coreless' carrot under control of a CaMV 35S promoter and two independent transgenic lines (NPR1-I and NPR1-XI) were identified by Southern and Northern blot hybridization. Both lines were phenotypically normal compared with non-transformed carrots. Northern analysis did not indicate constitutive or spontaneous induction in carrot cultures of SAR-related genes (DcPR-1, 2, 4, 5 or DcPAL). The duration and intensity of expression of DcPR-1, 2 and 5 genes were greatly increased compared with controls when the lines were treated with purified cell wall fragments of Sclerotinia sclerotiorum as well as with 2,6-dichloroisonicotinic acid. The two lines were challenged with the necrotrophic pathogens Botrytis cinerea, Alternaria radicina and S. sclerotiorum on the foliage and A. radicina on the taproots. Both lines exhibited 35-50% reduction in disease symptoms on the foliage and roots when compared with non-transgenic controls. Leaves challenged with the biotrophic pathogen Erysiphe heraclei or the bacterial pathogen Xanthomonas hortorum exhibited 90 and 80% reduction in disease development on the transgenic lines, respectively. The overexpression of the SAR controlling master switch in carrot tissues offers the ability to control a wide range of different pathogens, for which there is currently little genetic resistance available.
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Affiliation(s)
- Owen Wally
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada.
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148
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Lee CW, Efetova M, Engelmann JC, Kramell R, Wasternack C, Ludwig-Müller J, Hedrich R, Deeken R. Agrobacterium tumefaciens promotes tumor induction by modulating pathogen defense in Arabidopsis thaliana. THE PLANT CELL 2009; 21:2948-62. [PMID: 19794116 PMCID: PMC2768927 DOI: 10.1105/tpc.108.064576] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Revised: 09/02/2009] [Accepted: 09/10/2009] [Indexed: 05/18/2023]
Abstract
Agrobacterium tumefaciens causes crown gall disease by transferring and integrating bacterial DNA (T-DNA) into the plant genome. To examine the physiological changes and adaptations during Agrobacterium-induced tumor development, we compared the profiles of salicylic acid (SA), ethylene (ET), jasmonic acid (JA), and auxin (indole-3-acetic acid [IAA]) with changes in the Arabidopsis thaliana transcriptome. Our data indicate that host responses were much stronger toward the oncogenic strain C58 than to the disarmed strain GV3101 and that auxin acts as a key modulator of the Arabidopsis-Agrobacterium interaction. At initiation of infection, elevated levels of IAA and ET were associated with the induction of host genes involved in IAA, but not ET signaling. After T-DNA integration, SA as well as IAA and ET accumulated, but JA did not. This did not correlate with SA-controlled pathogenesis-related gene expression in the host, although high SA levels in mutant plants prevented tumor development, while low levels promoted it. Our data are consistent with a scenario in which ET and later on SA control virulence of agrobacteria, whereas ET and auxin stimulate neovascularization during tumor formation. We suggest that crosstalk among IAA, ET, and SA balances pathogen defense launched by the host and tumor growth initiated by agrobacteria.
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Affiliation(s)
- Chil-Woo Lee
- Julius-von-Sachs-Institute, Department of Molecular Plant Physiology and Biophysics, University of Wuerzburg, D-97082 Wuerzburg, Germany
| | - Marina Efetova
- Julius-von-Sachs-Institute, Department of Molecular Plant Physiology and Biophysics, University of Wuerzburg, D-97082 Wuerzburg, Germany
| | - Julia C Engelmann
- Theodor-Boveri-Institute, Department of Bioinformatics, University of Wuerzburg, D-97074 Wuerzburg, Germany
| | - Robert Kramell
- Department of Natural Product Biotechnology, Leibniz Institute of Plant Biochemistry, D-06120 Halle (Saale), Germany
| | - Claus Wasternack
- Department of Natural Product Biotechnology, Leibniz Institute of Plant Biochemistry, D-06120 Halle (Saale), Germany
| | - Jutta Ludwig-Müller
- Institute of Botany, Dresden University of Technology, D-01062 Dresden, Germany
| | - Rainer Hedrich
- Julius-von-Sachs-Institute, Department of Molecular Plant Physiology and Biophysics, University of Wuerzburg, D-97082 Wuerzburg, Germany
| | - Rosalia Deeken
- Julius-von-Sachs-Institute, Department of Molecular Plant Physiology and Biophysics, University of Wuerzburg, D-97082 Wuerzburg, Germany
- Address correspondence to
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149
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Lu H. Dissection of salicylic acid-mediated defense signaling networks. PLANT SIGNALING & BEHAVIOR 2009; 4:713-7. [PMID: 19820324 PMCID: PMC2801381 DOI: 10.4161/psb.4.8.9173] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Accepted: 06/03/2009] [Indexed: 05/18/2023]
Abstract
The small phenolic molecule salicylic acid (SA) plays a key role in plant defense. Significant progress has been made recently in understanding SA-mediated defense signaling networks. Functional analysis of a large number of genes involved in SA biosynthesis and regulation of SA accumulation and signal transduction has revealed distinct but interconnecting pathways that orchestrate the control of plant defense. Further studies utilizing combinatorial approaches in genetics, molecular biology, biochemistry and genomics will uncover finer details of SA-mediated defense networks as well as further insights into the crosstalk of SA with other defense signaling pathways. The complexity of defense networks illustrates the capacity of plants to integrate multiple developmental and environmental signals into a tight control of the costly defense responses.
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Affiliation(s)
- Hua Lu
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD 21250, USA.
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150
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Venugopal SC, Jeong RD, Mandal MK, Zhu S, Chandra-Shekara AC, Xia Y, Hersh M, Stromberg AJ, Navarre D, Kachroo A, Kachroo P. Enhanced disease susceptibility 1 and salicylic acid act redundantly to regulate resistance gene-mediated signaling. PLoS Genet 2009; 5:e1000545. [PMID: 19578402 PMCID: PMC2695777 DOI: 10.1371/journal.pgen.1000545] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Accepted: 06/01/2009] [Indexed: 11/19/2022] Open
Abstract
Resistance (R) protein-associated pathways are well known to participate in defense against a variety of microbial pathogens. Salicylic acid (SA) and its associated proteinaceous signaling components, including enhanced disease susceptibility 1 (EDS1), non-race-specific disease resistance 1 (NDR1), phytoalexin deficient 4 (PAD4), senescence associated gene 101 (SAG101), and EDS5, have been identified as components of resistance derived from many R proteins. Here, we show that EDS1 and SA fulfill redundant functions in defense signaling mediated by R proteins, which were thought to function independent of EDS1 and/or SA. Simultaneous mutations in EDS1 and the SA-synthesizing enzyme SID2 compromised hypersensitive response and/or resistance mediated by R proteins that contain coiled coil domains at their N-terminal ends. Furthermore, the expression of R genes and the associated defense signaling induced in response to a reduction in the level of oleic acid were also suppressed by compromising SA biosynthesis in the eds1 mutant background. The functional redundancy with SA was specific to EDS1. Results presented here redefine our understanding of the roles of EDS1 and SA in plant defense.
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Affiliation(s)
- Srivathsa C. Venugopal
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Rae-Dong Jeong
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Mihir K. Mandal
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Shifeng Zhu
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - A. C. Chandra-Shekara
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Ye Xia
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Matthew Hersh
- Department of Statistics, University of Kentucky, Lexington, Kentucky, United States of America
| | - Arnold J. Stromberg
- Department of Statistics, University of Kentucky, Lexington, Kentucky, United States of America
| | - DuRoy Navarre
- United States Department of Agriculture–Agricultural Research Service, Washington State University, Prosser, Washington, United States of America
| | - Aardra Kachroo
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Pradeep Kachroo
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
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