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Wirtz L, Massola Júnior NS, de Castro RRL, Ruge-Wehling B, Schaffrath U, Loehrer M. Colletotrichum spp. from Soybean Cause Disease on Lupin and Can Induce Plant Growth-Promoting Effects. Microorganisms 2021; 9:microorganisms9061130. [PMID: 34073656 PMCID: PMC8224748 DOI: 10.3390/microorganisms9061130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/15/2021] [Accepted: 05/17/2021] [Indexed: 11/16/2022] Open
Abstract
Protein crop plants such as soybean and lupin are attracting increasing attention because of their potential use as forage, green manure, or for the production of oil and protein for human consumption. Whereas soybean production only recently gained more importance in Germany and within the whole EU in frame of protein strategies, lupin production is already well-established in Germany. The cultivation of lupins is impeded by the hemibiotrophic ascomycete Colletotrichum lupini, the causal agent of anthracnose disease. Worldwide, soybean is also a host for a variety of Colletotrichum species, but so far, this seems to not be the case in Germany. Cross-virulence between lupin- and soybean-infecting isolates is a potential threat, especially considering the overlap of possible soybean and lupin growing areas in Germany. To address this question, we systematically investigated the interaction of different Colletotrichum species isolated from soybean in Brazil on German soybean and lupin plant cultivars. Conversely, we tested the interaction of a German field isolate of C. lupini with soybean. Under controlled conditions, Colletotrichum species from soybean and lupin were able to cross-infect the other host plant with varying degrees of virulence, thus underpinning the potential risk of increased anthracnose diseases in the future. Interestingly, we observed a pronounced plant growth-promoting effect for some host–pathogen combinations, which might open the route to the use of beneficial biological agents in lupin and soybean production.
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Affiliation(s)
- Louisa Wirtz
- Department of Plant Physiology, RWTH Aachen University, 52056 Aachen, Germany; (L.W.); (U.S.)
| | - Nelson Sidnei Massola Júnior
- Department of Plant Pathology and Nematology, ESALQ, University of São Paulo, Piracicaba 13418-900, SP, Brazil; (N.S.M.J.); (R.R.L.d.C.)
| | | | - Brigitte Ruge-Wehling
- Institute for Breeding Research on Agricultural Crops, Julius Kühn-Institut, 18190 Groß Lüsewitz, Germany;
| | - Ulrich Schaffrath
- Department of Plant Physiology, RWTH Aachen University, 52056 Aachen, Germany; (L.W.); (U.S.)
| | - Marco Loehrer
- Department of Plant Physiology, RWTH Aachen University, 52056 Aachen, Germany; (L.W.); (U.S.)
- Correspondence: ; Tel.: +49-241-8020101
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Elsharkawy MM. Induced systemic resistance against Cucumber mosaic virus by Phoma sp. GS8-2 stimulates transcription of pathogenesis-related genes in Arabidopsis. PEST MANAGEMENT SCIENCE 2019; 75:859-866. [PMID: 30168656 DOI: 10.1002/ps.5193] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/15/2018] [Accepted: 08/24/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Cucumber mosaic virus (CMV) is a serious threat to vegetable production worldwide. The efficacy of Phoma sp. GS8-2 was evaluated against CMV in Arabidopsis and cucumber plants. RESULTS Arabidopsis and cucumber plants treated with barley grain inoculum (BGI) or cell-free filtrate (CF) of GS8-2 demonstrated decreased CMV severity and titre using enzyme-linked immunosorbent assay relative to the control. Cucumber growth and yield parameters were significantly increased due to colonization with GS8-2 under field conditions. Molecular mechanisms underlying mediated resistance induced by GS8-2 against CMV were investigated. Real-time polymerase chain reaction (RT-PCR) results confirmed that both BGI and CF of GS8-2 stimulated the transcription levels of pathogenesis related genes (β1-3 glucanase, chitinase, PR1, PAL1 and LOX1), which could be involved in induced resistance against CMV. CONCLUSION Exploring the expression of the highly upregulated genes in GS8-2-induced plants suggested the contribution of multiple plant defence pathways against CMV. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Mohsen Mohamed Elsharkawy
- Department of Agricultural Botany, Faculty of Agriculture, Kafrelsheikh University, Kafr El-sheikh, Egypt
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Aqueous Garlic Extract as a Plant Biostimulant Enhances Physiology, Improves Crop Quality and Metabolite Abundance, and Primes the Defense Responses of Receiver Plants. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8091505] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Biostimulants are the next-generation choice for sustainable agricultural production and are gradually becoming an alternative to synthetic chemicals. Various botanicals are proposed to exert stimulatory effects, and garlic allelochemicals are among such botanicals; however, a peer-reviewed scientific evaluation is required to understand garlic-derived substances such as biostimulants. Current studies were therefore performed to identify the bioactivity of garlic extract as a biostimulant to improve crop quality, alter its physiological potential, and prime its defense responses against pathogenic fungal infections. 100 µg mL−1 aqueous garlic extracts (AGE) in consort with 1 mM of acetyl salicylic acid (ASA) and distilled water as a control treatment were applied to eggplant and pepper seedlings as foliar application and fertigation methods. The results revealed stimulatory responses in the growth of the vegetables with improved plant height, number of leaves, root growth, fresh and dry weight, etc., due to AGE and ASA applications. Moreover, significant alterations were indicated in plant metabolites such as chlorophyll, carotenoids, and soluble sugars. Additionally, stimulation of the antioxidant enzymes such as superoxide dismutase (SOD) and peroxidase (POD), as well as the root activity of these plants, was observed after treatment. Application of AGE and ASA also exerted priming effects on pepper plants, inducing defense responses prior to Phytopthora capsici inoculation, and the treated plants therefore successfully resisted infection through activated antioxidant systems, and probably carotenoid and other protectory metabolites. Stress-induced H2O2 content was extremely low in the treated plants, indicating successful resistance against pathogenic infection.
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Montenegro I, Madrid A. Synthesis of dihydroisorcordoin derivatives and their in vitro anti-oomycete activities. Nat Prod Res 2018; 33:1214-1217. [PMID: 29620446 DOI: 10.1080/14786419.2018.1460828] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A series of novel dihydrochalcone derivatives 2-7 were synthesized from dihydroisorcordoin 1 which was isolated from the aerial parts of Adesmia balsamica. The structures of all compounds were confirmed by 1H NMR, 13C NMR, and HRMS. Their anti-oomycete activity was evaluated in vitro against Saprolegnia parasitica and Saprolegnia diclina. Some of the newly synthesized compounds exhibited better anti-oomycete activities at low values compared with bronopol and fluconazole as positive controls. Among them, compound 7 exhibited strong activity, with minimum inhibitory concentration and minimum oomyceticidal concentration values of 75 and 100 μg/mL, respectively.
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Affiliation(s)
- Iván Montenegro
- a Escuela de Obstetricia y Puericultura, Facultad de medicina, Campus de la Salud , Universidad de Valparaíso , Viña del Mar , Chile
| | - Alejandro Madrid
- b Departamento de Química, Facultad de Ciencias Naturales y Exactas , Universidad de Playa Ancha , Valparaíso , Chile
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Wang M, Gao L, Dong S, Sun Y, Shen Q, Guo S. Role of Silicon on Plant-Pathogen Interactions. FRONTIERS IN PLANT SCIENCE 2017; 8:701. [PMID: 28529517 PMCID: PMC5418358 DOI: 10.3389/fpls.2017.00701] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 04/18/2017] [Indexed: 05/18/2023]
Abstract
Although silicon (Si) is not recognized as an essential element for general higher plants, it has beneficial effects on the growth and production of a wide range of plant species. Si is known to effectively mitigate various environmental stresses and enhance plant resistance against both fungal and bacterial pathogens. In this review, the effects of Si on plant-pathogen interactions are analyzed, mainly on physical, biochemical, and molecular aspects. In most cases, the Si-induced biochemical/molecular resistance during plant-pathogen interactions were dominated as joint resistance, involving activating defense-related enzymes activates, stimulating antimicrobial compound production, regulating the complex network of signal pathways, and activating of the expression of defense-related genes. The most previous studies described an independent process, however, the whole plant resistances were rarely considered, especially the interaction of different process in higher plants. Si can act as a modulator influencing plant defense responses and interacting with key components of plant stress signaling systems leading to induced resistance. Priming of plant defense responses, alterations in phytohormone homeostasis, and networking by defense signaling components are all potential mechanisms involved in Si-triggered resistance responses. This review summarizes the roles of Si in plant-microbe interactions, evaluates the potential for improving plant resistance by modifying Si fertilizer inputs, and highlights future research concerning the role of Si in agriculture.
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Affiliation(s)
| | | | | | | | | | - Shiwei Guo
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-Based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural UniversityNanjing, China
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Reeksting BJ, Coetzer N, Mahomed W, Engelbrecht J, van den Berg N. De novo sequencing, assembly, and analysis of the root transcriptome of Persea americana (Mill.) in response to Phytophthora cinnamomi and flooding. PLoS One 2014; 9:e86399. [PMID: 24563685 PMCID: PMC3919710 DOI: 10.1371/journal.pone.0086399] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 12/09/2013] [Indexed: 12/21/2022] Open
Abstract
Avocado is a diploid angiosperm containing 24 chromosomes with a genome estimated to be around 920 Mb. It is an important fruit crop worldwide but is susceptible to a root rot caused by the ubiquitous oomycete Phytophthora cinnamomi. Phytophthora root rot (PRR) causes damage to the feeder roots of trees, causing necrosis. This leads to branch-dieback and eventual tree death, resulting in severe losses in production. Control strategies are limited and at present an integrated approach involving the use of phosphite, tolerant rootstocks, and proper nursery management has shown the best results. Disease progression of PRR is accelerated under high soil moisture or flooding conditions. In addition, avocado is highly susceptible to flooding, with even short periods of flooding causing significant losses. Despite the commercial importance of avocado, limited genomic resources are available. Next generation sequencing has provided the means to generate sequence data at a relatively low cost, making this an attractive option for non-model organisms such as avocado. The aims of this study were to generate sequence data for the avocado root transcriptome and identify stress-related genes. Tissue was isolated from avocado infected with P. cinnamomi, avocado exposed to flooding and avocado exposed to a combination of these two stresses. Three separate sequencing runs were performed on the Roche 454 platform and produced approximately 124 Mb of data. This was assembled into 7685 contigs, with 106 448 sequences remaining as singletons. Genes involved in defence pathways such as the salicylic acid and jasmonic acid pathways as well as genes associated with the response to low oxygen caused by flooding, were identified. This is the most comprehensive study of transcripts derived from root tissue of avocado to date and will provide a useful resource for future studies.
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Affiliation(s)
- Bianca J Reeksting
- Department of Genetics, University of Pretoria, Pretoria, South Africa ; Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Nanette Coetzer
- Bioinformatics and Computational Biology Unit, Department of Biochemistry, University of Pretoria, Pretoria, South Africa ; Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Waheed Mahomed
- Department of Genetics, University of Pretoria, Pretoria, South Africa ; Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Juanita Engelbrecht
- Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Noëlani van den Berg
- Department of Genetics, University of Pretoria, Pretoria, South Africa ; Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
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Tang C, Wang X, Duan X, Wang X, Huang L, Kang Z. Functions of the lethal leaf-spot 1 gene in wheat cell death and disease tolerance to Puccinia striiformis. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:2955-69. [PMID: 23811695 PMCID: PMC3697956 DOI: 10.1093/jxb/ert135] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Pheophorbide a oxygenase (PaO) is a key enzyme in chlorophyll catabolism that is known to suppress cell death in maize and Arabidopsis. The catalytic activity of PaO in chlorophyll degradation has been clearly demonstrated, but the function of PaO in the regulation of cell death and plant-microbe interactions is largely unknown. In this study, we characterized a PaO homologue in wheat of the lethal leaf-spot 1 gene, TaLls1, that was induced in leaves infected by Puccinia striiformis f.sp. tritici (Pst) and wounding treatment. The TaLls1 protein contains a conserved Rieske [2Fe-2S] motif and a mononuclear iron-binding site typical of PaOs. Silencing of TaLls1 by virus-induced gene silencing in wheat led to leaf cell death without pathogen attacks, possibly due to the accumulation of pheophorbide a (upstream substrate of PaO), indicating a suppressor role of TaLls1, while overexpression of TaLls1 also triggered cell death in both tobacco and wheat leaves, probably owing to the accumulation of the red chlorophyll catabolite (downstream product of PaO). Further deletion mutant analysis showed that the conserved Rieske domain, but not the iron-binding site, was essential for cell death induction. These results thus suggest a threshold for TaLls1 in maintaining cell homeostasis to adapt in various stresses, and shed new light on the role of TaLls1 in cell death regulation. Furthermore, silencing of TaLls1 in wheat did not change the disease symptoms but enhanced tolerance to Pst via an significant increase in H2O2 generation, elevated cell death occurrence, and upregulation of pathogenesis-related genes.
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Affiliation(s)
- Chunlei Tang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, PR China
| | - Xiaojie Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, PR China
| | - Xiaoyuan Duan
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, PR China
| | - Xiaodong Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, PR China
| | - Lili Huang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, PR China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, PR China
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8
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Wang Y, Song J, Wu Y, Odeph M, Liu Z, Howlett BJ, Wang S, Yang P, Yao L, Zhao L, Yang Q. Eplt4 proteinaceous elicitor produced in Pichia pastoris has a protective effect against Cercosporidium sofinum infections of soybean leaves. Appl Biochem Biotechnol 2013; 169:722-37. [PMID: 23271623 DOI: 10.1007/s12010-012-0015-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 12/04/2012] [Indexed: 12/27/2022]
Abstract
A complementary DNA library was constructed from the mycelium of Trichoderma asperellum T4, and a highly expressed gene fragment named EplT4 was found. In order to find a more efficient and cost-effective way of obtaining EplT4, this study attempted to produce EplT4 using a Pichia pastoris expression system. The gene encoding EplT4, with an additional 6-His tag at the C-terminus, was cloned into the yeast vector pPIC9K and expressed in the P. pastoris strain GS115 to obtaining more protein for the further research. Transformants of P. pastoris were selected by PCR analysis, and the ability to secrete high levels of the EplT4 protein was determined. The optimal conditions for induction were assayed using the shake flask method and an enzyme-linked immunosorbent assay. The yield of purified EplT4 was approximately 20 mg/L by nickel affinity chromatography and gel-filtration chromatography. Western blot and matrix-assisted laser desorption/ionization time-of-flight mass spectrometer analysis revealed that the recombinant EplT4 was expressed in both its monomers and dimers. Soybean leaves treated with the EplT4 monomer demonstrated the induction of glucanase, chitinase III-A, cysteine proteinase inhibitor, and peroxidase genes. Early cellular events in plant defense response were also observed after incubation with EplT4. Soybean leaves protected by EplT4 against the pathogen Cercosporidium sofinum (Hara) indicated that EplT4 produced in P. pastoris was biologically active and would be potentially useful for improving food security.
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Affiliation(s)
- Yun Wang
- Department of Life Science and Engineering, Harbin Institute of Technology, Harbin 150001, China
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Fomicheva AS, Tuzhikov AI, Beloshistov RE, Trusova SV, Galiullina RA, Mochalova LV, Chichkova NV, Vartapetian AB. Programmed cell death in plants. BIOCHEMISTRY (MOSCOW) 2013; 77:1452-64. [DOI: 10.1134/s0006297912130044] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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10
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The infection capacity of P. expansum and P. digitatum on apples and histochemical analysis of host response. Int J Food Microbiol 2012; 157:360-7. [DOI: 10.1016/j.ijfoodmicro.2012.06.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 06/04/2012] [Accepted: 06/07/2012] [Indexed: 11/21/2022]
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Bosque-Pérez NA, Eigenbrode SD. The influence of virus-induced changes in plants on aphid vectors: Insights from luteovirus pathosystems. Virus Res 2011; 159:201-5. [DOI: 10.1016/j.virusres.2011.04.020] [Citation(s) in RCA: 151] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 04/14/2011] [Indexed: 11/29/2022]
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12
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Luo Y, Zhang DD, Dong XW, Zhao PB, Chen LL, Song XY, Wang XJ, Chen XL, Shi M, Zhang YZ. Antimicrobial peptaibols induce defense responses and systemic resistance in tobacco against tobacco mosaic virus. FEMS Microbiol Lett 2010; 313:120-6. [PMID: 21062346 DOI: 10.1111/j.1574-6968.2010.02135.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Trichoderma spp. are well-known biocontrol agents because of their antimicrobial activity against bacterial and fungal phytopathogens. However, the biochemical mechanism of their antiviral activity remains largely unknown. In this study, we found that Trichokonins, antimicrobial peptaibols isolated from Trichoderma pseudokoningii SMF2, could induce defense responses and systemic resistance in tobacco (Nicotiana tabacum var. Samsun NN) against tobacco mosaic virus (TMV) infection. Local Trichokonin (100 nM) treatment led to 54% lesion inhibition, 57% reduction in average lesion diameter and 30% reduction in average lesion area in systemic tissue of tobacco compared with control, indicating that Trichokonins induced resistance in tobacco against TMV infection. Trichokonin treatment increased the production of reactive oxygen species and phenolic compounds in tobacco. Additionally, application of Trichokonins significantly increased activities of pathogenesis-related enzymes PAL and POD, and upregulated the expression of several plant defense genes. These results suggested that multiple defense pathways in tobacco were involved in Trichokonin-mediated TMV resistance. We report on the antivirus mechanism of peptaibols, which sheds light on the potential of peptaibols in plant viral disease control.
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Affiliation(s)
- Yan Luo
- State Key Lab of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan, China
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Oliveira DC, Magalhães TA, Carneiro RGS, Alvim MN, Isaias RMS. Do Cecidomyiidae galls of Aspidosperma spruceanum (Apocynaceae) fit the pre-established cytological and histochemical patterns? PROTOPLASMA 2010; 242:81-93. [PMID: 20306094 DOI: 10.1007/s00709-010-0128-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 02/19/2010] [Indexed: 05/04/2023]
Abstract
Cecidomyiidae galls commonly present a zonation of tissues with lignified cell layers externally limiting a reserve tissue and internally limiting a specialized nutritive tissue next to the larval chamber. The cytological aspects of this specialized tissue indicate high metabolic activity as well as carbohydrate accumulation. In Aspidosperma spruceanum-Cecidomyiidae gall system, ultrastructural and histochemical investigations corroborated this pattern and also revealed the storage of proteins in the nutritive cells. Reactive oxygen species (ROS), callose, and pectin accumulation were related to the feeding activity of the galling herbivore. Phosphorylase, glucose-6-phosphatase, acid phosphatases, invertases, and sucrose synthase activities were detected for the first time, in the Neotropical region, and discussed in relation to gall maintenance and the feeding activity of the Cecidomyiidae.
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Affiliation(s)
- Denis Coelho Oliveira
- Instituto de Ciências Biológicas, Departamento de Botânica, Universidade Federal de Minas Gerais, ICB/UFMG, Cep: 31270-901, Belo Horizonte, MG, Brazil,
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Yoon J, Chung WI, Choi D. NbHB1, Nicotiana benthamiana homeobox 1, is a jasmonic acid-dependent positive regulator of pathogen-induced plant cell death. THE NEW PHYTOLOGIST 2009; 184:71-84. [PMID: 19645736 DOI: 10.1111/j.1469-8137.2009.02967.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Induction of cell death is an important component of plant defense against pathogens. There have been many reports on the role of phytohormones in pathogen-induced cell death, but jasmonic acid (JA) has not been implicated as a regulator of the response. Here, we report the function of NbHB1, Nicotiana benthamiana homeobox1, in pathogen-induced cell death in connection with JA signaling. Involvement of NbHB1 in cell death was analysed by gain- and loss-of-function studies using Agrobacterium-mediated transient overexpression and virus-induced gene silencing, respectively. Expression of NbHB1 following pathogen inoculations and various treatments was monitored by reverse transcription polymerase chain reaction. Transcript levels of NbHB1 were upregulated by infection with virulent and avirulent bacterial pathogens. Ectopic expression of NbHB1 accelerated cell death following treatment with darkness, methyl jasmonate, or pathogen inoculation. Conversely, when NbHB1 was silenced, pathogen-induced cell death was delayed. NbHB1-induced cell death was also delayed by silencing of NbCOI1, indicating a requirement for JA-mediated signaling. Overexpression of the domain-deleted proteins of NbHB1 revealed that the homeodomain, leucine zipper, and part of the variable N-terminal region were necessary for NbHB1 functionality. These results strongly suggest the role of NbHB1 in pathogen-induced plant cell death via the JA-mediated signaling pathway.
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Affiliation(s)
- Joonseon Yoon
- Department of Biological Sciences, KAIST, Daejeon, 305-701, Republic of Korea
- Department of Plant Science, Plant Genomics and Breeding Institute and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Won-Il Chung
- Department of Biological Sciences, KAIST, Daejeon, 305-701, Republic of Korea
| | - Doil Choi
- Department of Plant Science, Plant Genomics and Breeding Institute and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
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Fauteux F, Chain F, Belzile F, Menzies JG, Bélanger RR. The protective role of silicon in the Arabidopsis-powdery mildew pathosystem. Proc Natl Acad Sci U S A 2006; 103:17554-9. [PMID: 17082308 PMCID: PMC1859967 DOI: 10.1073/pnas.0606330103] [Citation(s) in RCA: 160] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The role and essentiality of silicon (Si) in plant biology have been debated for >150 years despite numerous reports describing its beneficial properties. To obtain unique insights regarding the effect of Si on plants, we performed a complete transcriptome analysis of both control and powdery mildew-stressed Arabidopsis plants, with or without Si application, using a 44K microarray. Surprisingly, the expression of all but two genes was unaffected by Si in control plants, a result contradicting reports of a possible direct effect of Si as a fertilizer. In contrast, inoculation of plants, treated or not with Si, altered the expression of a set of nearly 4,000 genes. After functional categorization, many of the up-regulated genes were defense-related, whereas a large proportion of down-regulated genes were involved in primary metabolism. Regulated defense genes included R genes, stress-related transcription factors, genes involved in signal transduction, the biosynthesis of stress hormones (SA, JA, ethylene), and the metabolism of reactive oxygen species. In inoculated plants treated with Si, the magnitude of down-regulation was attenuated by >25%, an indication of stress alleviation. Our results demonstrate that Si treatment had no effect on the metabolism of unstressed plants, suggesting a nonessential role for the element but that it has beneficial properties attributable to modulation of a more efficient response to pathogen stress.
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Affiliation(s)
- François Fauteux
- *Département de Phytologie–Faculté des Sciences de l'agriculture et de l'alimentation, Centre de Recherche en Horticulture, Université Laval, Pavillon Paul-Comtois, Québec, QC, Canada G1K 7P4
| | - Florian Chain
- *Département de Phytologie–Faculté des Sciences de l'agriculture et de l'alimentation, Centre de Recherche en Horticulture, Université Laval, Pavillon Paul-Comtois, Québec, QC, Canada G1K 7P4
| | - François Belzile
- Département de Phytologie–Faculté des Sciences de l'agriculture et de l'alimentation, Université Laval, Pavillon Charles-Eugène-Marchand, Québec, QC, Canada G1K 7P4; and
| | - James G. Menzies
- Agriculture and Agri-Food Canada, 195 Dafoe Road, Winnipeg, MB, Canada R3T 2M9
| | - Richard R. Bélanger
- *Département de Phytologie–Faculté des Sciences de l'agriculture et de l'alimentation, Centre de Recherche en Horticulture, Université Laval, Pavillon Paul-Comtois, Québec, QC, Canada G1K 7P4
- To whom correspondence should be addressed. E-mail:
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Djonović S, Pozo MJ, Dangott LJ, Howell CR, Kenerley CM. Sm1, a proteinaceous elicitor secreted by the biocontrol fungus Trichoderma virens induces plant defense responses and systemic resistance. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2006; 19:838-53. [PMID: 16903350 DOI: 10.1094/mpmi-19-0838] [Citation(s) in RCA: 181] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The soilborne filamentous fungus Trichoderma virens is a biocontrol agent with a well-known ability to produce antibiotics, parasitize pathogenic fungi, and induce systemic resistance in plants. Even though a plant-mediated response has been confirmed as a component of bioprotection by Trichoderma spp., the molecular mechanisms involved remain largely unknown. Here, we report the identification, purification, and characterization of an elicitor secreted by T. virens, a small protein designated Sm1 (small protein 1). Sm1 lacks toxic activity against plants and microbes. Instead, native, purified Sm1 triggers production of reactive oxygen species in monocot and dicot seedlings, rice, and cotton, and induces the expression of defense-related genes both locally and systemically in cotton. Gene expression analysis revealed that SM1 is expressed throughout fungal development under different nutrient conditions and in the presence of a host plant. Using an axenic hydroponic system, we show that SM1 expression and secretion of the protein is significantly higher in the presence of the plant. Pretreatment of cotton cotyledons with Sm1 provided high levels of protection to the foliar pathogen Colletotrichum sp. These results indicate that Sm1 is involved in the induction of resistance by Trichoderma spp. through the activation of plant defense mechanisms.
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Affiliation(s)
- Slavica Djonović
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, USA
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Fauteux F, Rémus-Borel W, Menzies JG, Bélanger RR. Silicon and plant disease resistance against pathogenic fungi. FEMS Microbiol Lett 2005; 249:1-6. [PMID: 16006059 DOI: 10.1016/j.femsle.2005.06.034] [Citation(s) in RCA: 309] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2005] [Revised: 06/03/2005] [Accepted: 06/07/2005] [Indexed: 01/06/2023] Open
Abstract
Silicon (Si) is a bioactive element associated with beneficial effects on mechanical and physiological properties of plants. Silicon alleviates abiotic and biotic stresses, and increases the resistance of plants to pathogenic fungi. Several studies have suggested that Si activates plant defense mechanisms, yet the exact nature of the interaction between the element and biochemical pathways leading to resistance remains unclear. Silicon possesses unique biochemical properties that may explain its bioactivity as a regulator of plant defense mechanisms. It can act as a modulator influencing the timing and extent of plant defense responses in a manner reminiscent of the role of secondary messengers in induced systemic resistance; it can also bind to hydroxyl groups of proteins strategically involved in signal transduction; or it can interfere with cationic co-factors of enzymes influencing pathogenesis-related events. Silicon may therefore interact with several key components of plant stress signaling systems leading to induced resistance.
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Affiliation(s)
- François Fauteux
- Département de phytologie - FSAA, Centre de recherche en horticulture, Université Laval, Pavillon Paul-Comtois, local 3305, Québec, Que., Canada G1K 7P4
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Pegard A, Brizzard G, Fazari A, Soucaze O, Abad P, Djian-Caporalino C. Histological Characterization of Resistance to Different Root-Knot Nematode Species Related to Phenolics Accumulation in Capsicum annuum. PHYTOPATHOLOGY 2005; 95:158-65. [PMID: 18943985 DOI: 10.1094/phyto-95-0158] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
ABSTRACT In the pepper Capsicum annuum CM334, which is used by breeders as a source of resistance to Phytophthora spp. and potyviruses, a resistance gene entirely suppresses reproduction of the root-knot nematode (Meloidogyne spp.). The current study compared the histological responses of this resistant line and a susceptible cultivar to infection with the three most damaging root-knot nematodes: M. arenaria, M. incognita, or M. javanica. Resistance of CM334 to root-knot nematodes was associated with unidentified factors that limited nematode penetration and with post-penetration biochemical responses, including the hypersensitive response, which apparently blocked nematode migration and thereby prevented juvenile development and reproduction. High-performance liquid chromatography analysis suggested that phenolic compounds, especially chlorogenic acid, may be involved in CM334 resistance. The response to infection in the resistant line varied with root-knot nematode species and was correlated with nematode behavior and pathogenicity in the susceptible cultivar: nematode species that quickly reached the vascular cylinder and initiated feeding sites in the susceptible cultivar were quickly recognized in CM334 and stopped in the epidermis or cortex. After comparing our data with those from other resistant pepper lines, we suggest that timing of the resistance response and the mechanism of resistance vary with plant genotype, resistance gene, and root-knot nematode species.
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Mlícková K, Luhová L, Lebeda A, Mieslerová B, Pec P. Reactive oxygen species generation and peroxidase activity during Oidium neolycopersici infection on Lycopersicon species. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2004; 42:753-61. [PMID: 15596094 DOI: 10.1016/j.plaphy.2004.07.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2004] [Accepted: 07/20/2004] [Indexed: 05/01/2023]
Abstract
Histochemical and biochemical study of plant tissue responses were carried out on three Lycopersicon spp. accessions differing in response to Oidium neolycopersici. High production of superoxide anion was observed mainly in infected leaves of highly susceptible Lycopersicon esculentum cv. 'Amateur' during the first hours post inoculation (hpi). The production of hydrogen peroxide as well as an increase of peroxidase (POX) activity were detected mainly in resistant accessions at 4-12 hpi. A signal confirming the presence of very active POX was found in the apical part of tubes of germinating fungus and inside dead conidia. Increased soluble POX and catalase activity in leaf extracts of resistant accessions L. chmielewskii (LA 2663) and L. hirsutum (LA 2128) (20 hpi) correlated with the percentage of dead cells in infection sites. The correlation between production of reactive oxygen species (ROS) and activity of enzymes participating in their metabolism and hypersensitive response was evident during plant defence response.
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Affiliation(s)
- Katerina Mlícková
- Department of Botany, Faculty of Science, Palacký University, Slechtitelů 11, 783 71 Olomouc, Czech Republic
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Bretz JR, Hutcheson SW. Role of type III effector secretion during bacterial pathogenesis in another kingdom. Infect Immun 2004; 72:3697-705. [PMID: 15213109 PMCID: PMC427461 DOI: 10.1128/iai.72.7.3697-3705.2004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- James R Bretz
- Department of Cell Biology and Molecular Genetics, Microbiology Bldg., University of Maryland, College Park, MD 20742, USA
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Divéki Z, Salánki K, Balázs E. The necrotic pathotype of the cucumber mosaic virus (CMV) ns strain is solely determined by amino acid 461 of the 1a protein. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2004; 17:837-45. [PMID: 15305604 DOI: 10.1094/mpmi.2004.17.8.837] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The unique Ns isolate of Cucumber mosaic virus (CMV) induces necrotic lesions on several Nicotiana spp. in contrast to other strains that cause systemic mosaic on these plants. By using biologically active RNA transcripts from cDNAs of Ns-CMV and a reference subgroup I strain Rs-CMV, we confined the genetic determinant solely responsible for necrosis induction to amino acid 461 of the la protein translated from genomic RNA1. An Arg to Cys change at this position (R461C) rendered Rs-CMV necrotic, whereas the reciprocal C461R mutation reverted the necrotic phenotype of Ns-CMV. Necrotic (Ns-CMV, R461C) and non-necrotic (Rs-CMV and C461R) viruses accumulated to similar levels in Nicotiana clevelandii protoplasts. Deletion of the residue at position 461 abolished replicase activity of the Ns-CMV 1a protein. The R461C mutation also was introduced into the 1a protein of Trk7-CMV, a subgroup II isolate. Symptoms induced by the Trk7/R461C mutant were identical to those caused by wild-type Trk7-CMV, even when the mutant Trk7 RNA1 was co-inoculated with RNA2 and 3 of the necrotic Ns strain.
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Affiliation(s)
- Zoltán Divéki
- Agricultural Biotechnology Center, Environmental Biosafety Research Institute, P.O. Box 411. Gödöllö, H-2101 Hungary
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Expression ofCryptogein in tobacco plants exhibits enhanced disease resistance and tolerance to salt stress. CHINESE SCIENCE BULLETIN-CHINESE 2004. [DOI: 10.1007/bf02889751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Garbeva P, Veen JA, Elsas JD. Assessment of the diversity, and antagonism towards Rhizoctonia solani AG3, of Pseudomonas species in soil from different agricultural regimes. FEMS Microbiol Ecol 2004; 47:51-64. [DOI: 10.1016/s0168-6496(03)00234-4] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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Bargabus RL, Zidack NK, Sherwood JE, Jacobsen BJ. Oxidative burst elicited by Bacillus mycoides isolate Bac J, a biological control agent, occurs independently of hypersensitive cell death in sugar beet. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2003; 16:1145-53. [PMID: 14651348 DOI: 10.1094/mpmi.2003.16.12.1145] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Response of sugar beet cultivars C40 and USH11 to syringe infiltration of live and dead Bacillus mycoides isolate Bac J, a biological control agent, and virulent and avirulent isolates of Erwinia carotovora pv. betavasculorum was measured by monitoring systemic acquired resistance control of Cercospora beticola, specific activity of chitinase and beta-glucanase, the oxidative burst, and hypersensitive cell death at the infiltration site. Priming sugar beet with B. mycoides Bac J (1 x 10(8) cells/ml) and avirulent isolates of E. carotovora pv. betavasculorum (1 x 10(6) cells/ml) reduced C. beticola symptoms by nearly 70% on distal, untreated leaves. Systemic resistance responses elicited by live B. mycoides Bac J and avirulent E. carotovora pv. betavasculorum isolates, measured by assays for chitinase and beta-glucanase, were statistically equivalent, and biphasic hydrogen peroxide production was observed. Although similar in timing, the second hydrogen peroxide burst was twofold lower for B. mycoides Bac J than for avirulent E. carotovora pv. betavasculorum. Hypersensitive cell death was elicited by avirulent E. carotovora pv. betavasculorum but not B. mycoides Bac J. An oxidative burst was elicited by spray-applied B. mycoides Bac J under both light and green light conditions, indicating that the signal produced by B. mycoides Bac J was not reliant on the stomata for entry into sugar beet. A working model for signal delivery and systemic resistance induction by B. mycoides Bac J in sugar beet is proposed.
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Affiliation(s)
- Rebecca L Bargabus
- Department of Plant Science and Plant Pathology, Montana State University, 119 AgBioSciences Facility, Bozeman 59717-3150, USA
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Kangatharalingam N, Pierce ML, Essenberg M. A Technique for Precise Inoculation of the Internal Phyllosphere of Cotton with Xanthomonas campestris pv. malvacearum. PHYTOPATHOLOGY 2003; 93:1204-1208. [PMID: 18944317 DOI: 10.1094/phyto.2003.93.10.1204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
ABSTRACT A technique was developed to inoculate uniformly and gently the internal phyllosphere from the upper surface of cotton leaves with the phytopathogenic bacterium Xanthomonas campestris pv. malvacearum. The inoculum consisted of 2 to 3 x 10(7) CFU/ml in CaCO(3)-saturated sterile distilled water containing 0.02%, vol/vol, of the wetting agent Silwet L-77. A custom-made inoculation apparatus was employed to immerse a circular area of the adaxial surface of a leaf in inoculum for 90 s. This resulted in uniform, passive entry of bacteria into the substomatal chambers, producing an endophytic bacterial population of 2 x 10(4) CFU/cm(2). Microscopic signs of infection were visible 48 to 72 h after inoculation. In susceptible leaves, uniformly distributed water-soaked spots were observed 7 to 8 days after inoculation. When the technique was used on resistant leaves, the autofluorescence that is characteristic of hypersensitively necrotic cells developed in the guard cells and palisade cells lining substomatal chambers, but not in the underlying spongy mesophyll.
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Bretz JR, Mock NM, Charity JC, Zeyad S, Baker CJ, Hutcheson SW. A translocated protein tyrosine phosphatase of Pseudomonas syringae pv. tomato DC3000 modulates plant defence response to infection. Mol Microbiol 2003; 49:389-400. [PMID: 12828637 DOI: 10.1046/j.1365-2958.2003.03616.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Pseudomonas syringae strains translocate effector proteins into host cells via the hrp-encoded type III protein secretion system (TTSS) to facilitate pathogenesis in susceptible plants. However, the mechanisms by which pathogenesis is favoured by these effectors are not well understood. Individual strains express multiple effectors with apparently distinct activities that are co-ordinately regulated by the alternative sigma factor HrpL. Genes for several effectors were identified in the P. syringae pv. tomato DC3000 genome using a promoter trap assay to identify HrpL-dependent promoters. In addition to orthologues of avrPphE and hrpW, an unusual allele of avrPphD was detected that carried an IS52 insertion. Using this avrPphD::IS52 allele as a probe, a wild-type allele of avrPphD, hopPtoD1, and a chimeric homologue were identified in the DC3000 genome. This chimeric homologue, identified as HopPtoD2 in the annotated DC3000 genome, consisted of an amino terminal secretion domain similar to that of AvrPphD fused to a potential protein tyrosine phosphatase domain. Culture filtrates of strains expressing HopPtoD2 were able to dephosphorylate pNPP and two phosphotyrosine peptides. HopPtoD2 was shown to be translocated into Arabidopsis thaliana cells via the hrp-encoded TTSS. A DeltahopPtoD2 mutant of DC3000 exhibited strongly reduced virulence in Arabidopsis thaliana. Ectopic expression of hopPtoD2 in P. syringae Psy61 that lacks a native hopPtoD2 orthologue delayed the development of several defence-associated responses including programmed cell death, active oxygen production and transcription of the pathogenesis-related gene PR1. The results indicate that HopPtoD2 is a translocated effector with protein tyrosine phosphatase activity that modulates plant defence responses.
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Affiliation(s)
- James R Bretz
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
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Charity JC, Pak K, Delwiche CF, Hutcheson SW. Novel exchangeable effector loci associated with the Pseudomonas syringae hrp pathogenicity island: evidence for integron-like assembly from transposed gene cassettes. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2003; 16:495-507. [PMID: 12795376 DOI: 10.1094/mpmi.2003.16.6.495] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Pseudomonas syringae strains use a type III secretion system (TTSS) to translocate effector proteins that assist in the parasitism of host plant cells. Some genes for effector proteins are clustered in the exchangeable effector locus (EEL) associated with the hrp pathogenicity island. A polymerase chain reaction-based screen was developed to amplify the EEL from P. syringae strains. Of the 86 strains screened, the EEL was successfully amplified from 30 predominately North American P. syringae pv. syringae strains using hrpK and queA-derived primers and from an additional three strains using hrpL and queA-derived primers. Among the amplified EEL, ten distinct types of EEL were identified that could be classified into six families distinguishable by genetic composition, but other types of EEL may be present in strains isolated in other geographical regions. No linkage with the host range of the source strain was apparent. Gene cassettes carrying conserved flanking, coding, and intergenic sequences, present in different combinations, were identified in the characterized EEL. Six new alleles of known effectors were identified that differed from the homolog in sequence, size, or both of the gene. One of these apparently novel effector proteins, HopPsyB, retained a strongly conserved amino terminus similar to that of HopPsyA, but other regions of the two polypeptides were only weakly similar. hopPsyB was expressed from an apparent operon that included hrpK and a shcA homolog, shcB. Escherichia coli MC4100 expressing the hrp TTSS, ShcB, and HopPsyB elicited the hypersensitive response (HR) in tobacco, consistent with effector production. Indicative of translocation as an effector, P. syringae pv. tomato DC3000 expressing a HopPsyB':'AvrRpt2 fusion elicited the HR in RPS2+ Arabidopsis thaliana. P. syringae pv. tomato DC3000 carrying HopPsyB exhibited slightly enhanced virulence in several Brassica spp. These results are consistent with the hypotheses that the EEL is a source of disparate effectors functioning in pathogenicity of P. syringae strains and that it evolved independently of the hrp pathogenicity island central conserved region, most likely through integron-like assembly of transposed gene cassettes.
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Affiliation(s)
- James C Charity
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
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Gonzalez Ureña A, Orea JM, Montero C, Jiménez JB, González JL, Sánchez A, Dorado M. Improving postharvest resistance in fruits by external application of trans-resveratrol. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2003; 51:82-89. [PMID: 12502389 DOI: 10.1021/jf020663v] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
As it is well-known, one of the main problems of modern agriculture is the postharvest fruit losses due to pathogen's attack and natural senescence during storage. Well established solutions to improve this situation, such as, for example, storage under controlled conditions and the use of synthetic pesticides, are not free of problems due to human health risks and environmental effects caused by chemical pesticides. A new strategy to solve these problems consists of developing methods to improve the natural plant resistance by using, upon their identification, the plant's own defense molecules, in other words, applying methods based on the plant's own natural processes of pest suppression to control spoilage. This requires the identification of components of the natural defense response in plants, which, in turn, demands highly sensitive, fast, and versatile analytical methods especially for trace, nonvolatile, compounds. In this work a laser-based technique has been applied for screening the postharvest elicitation of resveratrol by Botrytis cinerea in grapes. Besides antifungal character, resveratrol is known to present important antioxidant properties, which could also have positive effects on fruit conservation during storage. Consequently, several experiments were carried out in which exogenous application of resveratrol to several fruits maintained their postharvest quality. The quality of both resveratrol-treated and untreated fruits has been studied by the assessment of the biochemical composition and sensory analysis. Indeed, the present work demonstrates that the external application of resveratrol does not alter the sensorial and biochemical properties of the fruit.
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Affiliation(s)
- A Gonzalez Ureña
- Cayacea S.A., Miguel Yuste 12, 4 degrees, E-28037 Madrid, Spain.
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Venisse JS, Malnoy M, Faize M, Paulin JP, Brisset MN. Modulation of defense responses of Malus spp. during compatible and incompatible interactions with Erwinia amylovora. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2002; 15:1204-1212. [PMID: 12481992 DOI: 10.1094/mpmi.2002.15.12.1204] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Erwinia amylovora is the causal agent of fire blight, a disease affecting members of subfamily Maloideae. In order to analyze mechanisms leading to compatible or incompatible interactions, early plant molecular events were investigated in two genotypes of Malus with contrasting susceptibility to fire blight, after confrontation with either E. amylovora or the incompatible tobacco pathogen Pseudomonas syringae pv. tabaci. Many defense mechanisms, including generation of an oxidative burst and accumulation of pathogenesis-related proteins, were elicited in both resistant and susceptible genotypes by the two pathogens at similar rates and according to an equivalent time course. This elicitation was linked with the functional hypersensitive reaction and pathogenicity (hrp) cluster of E. amylovora, because an hrp secretion mutant did not induce such responses. However, a delayed induction of several genes of various branch pathways of the phenylpropanoid metabolism was recorded in tissues of the susceptible genotype challenged with the wild-type strain of E. amylovora, whereas these genes were quickly induced in every other plant-bacteria interaction, including interactions with the hrp secretion mutant. This suggests the existence of hrp-independent elicitors of defense in the fire blight pathogen as well as hrp-dependant mechanisms of suppression of these nonspecific inductions.
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Affiliation(s)
- Jean-Stéphane Venisse
- Unité d'Amélioration des Espèces Fruitières et Ornementales, INRA, Beaucouzé, France
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May KJ, Whisson SC, Zwart RS, Searle IR, Irwin JAG, Maclean DJ, Carroll BJ, Drenth A. Inheritance and mapping of 11 avirulence genes in Phytophthora sojae. Fungal Genet Biol 2002; 37:1-12. [PMID: 12223184 DOI: 10.1016/s1087-1845(02)00027-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two new crosses involving four races (races 7, 16, 17, and 25) of the soybean root and stem rot pathogen Phytophthora sojae were established (7/16 cross; 17/25 cross). An F2 population derived from each cross was used to determine the genetic basis of avirulence towards 11 different resistance genes in soybean. Avirulence was found to be dominant and determined by a single locus for Avr1b, 1d, 1k, 3b, 4, and 6, as expected for a simple gene-for-gene model. We also observed several cases of segregation, inconsistent with a single dominant gene being solely responsible for avirulence, which suggests that the genetic background of the different crosses can affect avirulence. Avr4 and 6 cosegregated in both the 7/16 and 17/25 crosses and, in the 7/16 cross, Avr1b and 1k were closely linked. Information from segregating RAPD, RFLP, and AFLP markers screened on F2 progeny from the two new crosses and two crosses described previously (a total of 212 F2 individuals, 53 from each cross) were used to construct an integrated genetic linkage map of P. sojae. This revised genetic linkage map consists of 386 markers comprising 35 RFLP, 236 RAPD, and 105 AFLP markers, as well as 10 avirulence genes. The map is composed of 21 major linkage groups and seven minor linkage groups covering a total map distance of 1640.4cM.
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Affiliation(s)
- K J May
- Cooperative Research Centre for Tropical Plant Protection, The University of Queensland, Brisbane, Qld, Australia
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Banks WA, Niehoff ML, Brown RL, Chen ZY, Cleveland TE. Transport of an antifungal trypsin inhibitor isolated from corn across the blood-brain barrier. Antimicrob Agents Chemother 2002; 46:2633-5. [PMID: 12121944 PMCID: PMC127332 DOI: 10.1128/aac.46.8.2633-2635.2002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2002] [Revised: 04/01/2002] [Accepted: 04/22/2002] [Indexed: 11/20/2022] Open
Abstract
We determined whether an antifungal 14-kDa protein trypsin inhibitor isolated from corn is able to cross the blood-brain barrier. We found that it completely crossed the blood-brain barrier by means of a saturable mechanism at a rate of 0.153 microl/g. min, with about 0.082% of the intravenously injected dose being taken up per gram of brain.
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Affiliation(s)
- William A Banks
- Geriatric Research, Educational, and Clinical Center, Veterans Affairs Medical Center, 915 N Grand Boulevard, St. Louis, MO 63106, USA.
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Abstract
Nonselective cation channels are a diverse group of ion channels characterized by their low discrimination between many essential and toxic cations. They are ubiquitous in plant tissues and are active in the plasma membrane, tonoplast, and other endomembranes. Members of this group are likely to function in low-affinity nutrient uptake, in distribution of cations within and between cells, and as plant Ca2+ channels. They are gated by diverse mechanisms, which can include voltage, cyclic nucleotides, glutamate, reactive oxygen species, and stretch. These channels dominate tonoplast cation transport, and the selectivity and gating mechanisms of tonoplast nonselective cation channels are comprehensively reviewed here. This review presents the first classification of plant nonselective cation channels and the first full description of nonselective cation channel candidate sequences in the Arabidopsis genome.
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Affiliation(s)
- Vadim Demidchik
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, United Kingdom.
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Chen ZY, Brown RL, Cleveland TE, Damann KF, Russin JS. Comparison of constitutive and inducible maize kernel proteins of genotypes resistant or susceptible to aflatoxin production. J Food Prot 2001; 64:1785-92. [PMID: 11726160 DOI: 10.4315/0362-028x-64.11.1785] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Maize genotypes resistant or susceptible to aflatoxin production or contamination were compared for differences in both constitutive and inducible proteins. Five additional constitutive proteins were found to be associated with resistance in over 8 of the 10 genotypes examined. Among these, the 58- and 46-kDa proteins were identified as globulin-1 and globulin-2, respectively. Differences in the ability to induce specific antifungal proteins, such as the higher synthesis of the 22-kDa zeamatin in resistant genotypes, were also observed between resistant and susceptible kernels incubated under germinating conditions (31 degrees C, 100% humidity). Both constitutive and inducible proteins appear to be necessary for kernel resistance. Embryo-killed kernels (unable to synthesize new proteins) supported the highest level of aflatoxins, whereas imbibed kernels (to hasten protein induction) supported the lowest among all treatments. This suggests that the synthesis of new proteins by the embryo plays an important role in conferring resistance. However, significantly lower levels of aflatoxin production in embryo-killed resistant kernels than in susceptible ones suggest that, in reality, high levels of constitutive antifungal proteins are indispensable to kernel resistance.
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Affiliation(s)
- Z Y Chen
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge 70803, USA
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Hutcheson SW, Bretz J, Sussan T, Jin S, Pak K. Enhancer-binding proteins HrpR and HrpS interact to regulate hrp-encoded type III protein secretion in Pseudomonas syringae strains. J Bacteriol 2001; 183:5589-98. [PMID: 11544221 PMCID: PMC95450 DOI: 10.1128/jb.183.19.5589-5598.2001] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Pseudomonas syringae strains, the hrp-hrc pathogenicity island consists of an HrpL-dependent regulon that encodes a type III protein translocation complex and translocated effector proteins required for pathogenesis. HrpR and HrpS function as positive regulatory factors for the hrpL promoter, but their mechanism of action has not been established. Both HrpR and HrpS are structurally related to enhancer-binding proteins, but they lack receiver domains and do not appear to require a cognate protein kinase for activity. hrpR and hrpS were shown to be expressed as an operon: a promoter was identified 5' to hrpR, and reverse transcriptase PCR detected the presence of an hrpRS transcript. The hrpR promoter and coding sequence were conserved among P. syringae strains. The coding sequences for hrpR and hrpS were cloned into compatible expression vectors, and their activities were monitored in Escherichia coli transformants carrying an hrpL'-lacZ fusion. HrpS could function as a weak activator of the hrpL promoter, but the activity was only 2.5% of the activity detected when both HrpR and HrpS were expressed in the reporter strain. This finding is consistent with a requirement for both HrpR and HrpS in the activation of the hrpL promoter. By using a yeast two-hybrid assay, an interaction between HrpR and HrpS was detected, suggestive of the formation of a heteromeric complex. Physical interaction of HrpR and HrpS was confirmed by column-binding experiments. The results show that HrpR and HrpS physically interact to regulate the sigma(54)-dependent hrpL promoter in P. syringae strains.
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Affiliation(s)
- S W Hutcheson
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742, USA.
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Mayer AM, Staples RC, Gil-ad NL. Mechanisms of survival of necrotrophic fungal plant pathogens in hosts expressing the hypersensitive response. PHYTOCHEMISTRY 2001; 58:33-41. [PMID: 11524110 DOI: 10.1016/s0031-9422(01)00187-x] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The hypersensitive response (HR), elicited when resistant hosts are infected by incompatible races of biotrophic fungi, has been researched extensively. New studies on host responses to necrotrophic fungi are beginning to show that when the HR occurs in hosts colonized by necrotrophs, fungal growth is accelerated rather than retarded. We review current knowledge about how necrotrophs survive in host plants in which the HR is expressed. We discuss how necrotrophs cope with the environmental factors formed as a result of the HR. Necrotrophs contain an array of enzymes, which can help in exploiting the hostile environment in order to colonize the host and to remove or inactivate active oxygen species (AOS). Among this array of enzymes are superoxide dismutase (SOD), peroxidases, catalase, and perhaps laccases and polyphenol oxidases. Of these, only SOD and catalase have been studied in any detail. The precise significance of SOD and catalase in host invasion and fungal resistance is still not adequately known. The importance of different peroxidases is also still far from clear. We speculate that AOS species may trigger the response of necrotrophs to the host environment.
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Affiliation(s)
- A M Mayer
- Department of Botany, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram Campus, Jerusalem 91904, Israel.
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38
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Hennin C, Höfte M, Diederichsen E. Functional expression of Cf9 and Avr9 genes in Brassica napus induces enhanced resistance to Leptosphaeria maculans. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2001; 14:1075-1085. [PMID: 11551072 DOI: 10.1094/mpmi.2001.14.9.1075] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The tomato Cf9 resistance gene induces an Avr9-dependent hypersensitive response (HR) in tomato and transgenic Solanaceae spp. We studied whether the Cf9 gene product responded functionally to the corresponding Avr9 gene product when introduced in a heterologous plant species. We successfully expressed the Cf9 gene under control of its own promoter and the Avr9 or Avr9R8K genes under control of the p35S1 promoter in transgenic oilseed rape. We demonstrated that the transgenic oilseed rape plants produced the Avr9 elicitor with the same specific necrosis-inducing activity as reported for Cladosporium fulvum. An Avr9-dependent HR was induced in Cf9 oilseed rape upon injection of intercellular fluid containing Avr9. We showed Avr9-specific induction of PR1, PR2, and Cxc750 defense genes in oilseed rape expressing CJ9. Cf9 x Avr9 oilseed rape did not result in seedling death of the F1 progeny, independent of the promoters used to express the genes. The F1 (Cf9 x Avr9) plants, however, were quantitatively more resistant to Leptosphaeria maculans. Phytopathological analyses revealed that disease development of L. maculans was delayed when the pathogen was applied on an Avr9-mediated HR site. We demonstrate that the CJ9 and Avr9 gene can be functionally expressed in a heterologous plant species and that the two components confer an increase in disease resistance.
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Affiliation(s)
- C Hennin
- Faculty of Agricultural and Applied Biological Sciences, Laboratory of Phytopathology, Ghent University, Belgium
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Potenza C, Thomas SH, Sengupta-Gopalan C. Genes induced during early response to Meloidogyne incognita in roots of resistant and susceptible alfalfa cultivars. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2001; 161:289-299. [PMID: 11448760 DOI: 10.1016/s0168-9452(01)00415-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
A cDNA library made to RNA from roots of Meloidogyne incognita (root-knot nematode) susceptible alfalfa cv. Lahontan seedlings 72 h after root-knot nematode inoculation was differentially screened with cDNA made from uninoculated control and M. incognita infested (72 h) root RNA. Of the six cDNAs isolated, the deduced amino acid sequences of four showed significant homology to sequences present in the databank, while two were pioneer sequences. The four cDNAs with matches to known sequences include those for glycine-rich protein, the gluconeogenic pathway enzyme phosphoenolpyruvate carboxykinase, an isoflavone reductase-like protein, and metallothionein. We have followed the expression of these genes during the course of nematode infection in both the susceptible and resistant host and also in different plant organs. Based on these analyses, the genes induced early in nematode infection are related either to metabolic pathways or to stress/defense.
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Affiliation(s)
- C Potenza
- Department of Agronomy and Horticulture, New Mexico State University, 88003, Las Cruces, NM, USA
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40
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Duvick J. Prospects for reducing fumonisin contamination of maize through genetic modification. ENVIRONMENTAL HEALTH PERSPECTIVES 2001; 109 Suppl 2:337-42. [PMID: 11359705 PMCID: PMC1240685 DOI: 10.1289/ehp.01109s2337] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Fumonisins (FB) are mycotoxins found in (italic)Fusarium verticillioides-infected maize grain worldwide. Attention has focused on FBs because of their widespread occurrence, acute toxicity to certain livestock, and their potential carcinogenicity. FBs are present at low levels in most field-grown maize but may spike to high levels depending on both the environment and genetics of the host plant. Among the strategies for reducing risk of FB contamination in maize supplied to the market, development and deployment of Fusarium ear mold-resistant maize germplasm is a high priority. Breeding for increased ear mold tolerance and reduced mycotoxin levels is being practiced today in both commercial and public programs, but the amount of resistance achievable may be limited due to complicated genetics and/or linkage to undesirable agronomic traits. Molecular markers can be employed to speed up the incorporation of chromosomal regions that have a quantitative effect on resistance (quantitative trait loci). Transgenic approaches to ear mold/mycotoxin resistance are now feasible as well. These potentially include genetically enhanced resistance to insect feeding, increased fungal resistance, and detoxification/prevention of mycotoxins in the grain. An example of the first of these approaches is already on the market, namely transgenic maize expressing Bacillus thuringiensis (Bt) toxin, targeted to the European corn borer. Some Bt maize hybrids have the potential to reduce FB levels in field-harvested grain, presumably through reduced feeding of Bt-susceptible insects in ear tissues. However, improved ear mold resistance per se is still an important goal, as the plant will still be vulnerable to noninsect routes of entry to (italic)Fusarium. A second approach, transgene-mediated control of the ability of Fusarium to infect and colonize the ear, could potentially be achieved through overexpression of specific antifungal proteins and metabolites, or enhancement of the plant's own defense systems in kernel tissues. This has not yet been accomplished in maize, although promising results have been obtained recently in other monocots versus other fungal and bacterial pathogens. Achieving reproducible and stable enhanced ear mold resistance under field conditions will be immensely challenging for biotechnologists. A third approach, transgene strategies aimed at preventing mycotoxin biosynthesis, or detoxifying mycotoxins in planta, could provide further protection for the grower in environments where FBs present a risk to the crop even when the maize is relatively resistant to Fusarium mold. In one example of such a strategy, enzymes that degrade FBs have been identified in a filamentous saprophytic fungus isolated from maize, and corresponding genes have been cloned and are currently being tested in transgenic maize.
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Affiliation(s)
- J Duvick
- Disease Resistance Group, Trait and Technology Division, Pioneer Hi-Bred, International, Inc., Johnston, Iowa, USA.
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41
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Abstract
• The effects are reported here of an elicitor prepared from liquid cultures of an isolate of Verticillium albo-atrum, which is nonpathogenic to Medicago sativa, on accumulation of H2 O2 , medicarpin, deposition of phenolic polymer and phenylalanine ammonia-lyase (PAL) activity in cultured cells of Medicago sativa L. cv. Kabul (lucerne). • PAL activity and phytoalexins were assayed spectrophotometically and by HPLC, respectively. The scopoletin fluorescence-quenching and thioglycolic acid methods were used to measure H2 O2 and phenolic polymer deposition, respectively. • Studies with inhibitors suggested that an NAD(P)H oxidase and a peroxidase were involved in the elicitor stimulated accumulation of H2 O2 and that an increase in cytosolic Ca2+ , but not H2 O2 , was part of a signalling pathway leading to the induction of defence responses. • Both the influx of Ca2+ and release of Ca2+ from intracellular stores forms part of the signalling pathway leading from perception of elicitor to induction of defence responses. Although H2 O2 is not part of the pathway, evidence is presented that O2 - is part of the signal transduction chain.
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Affiliation(s)
- M Tang
- Biochemistry Research Group, School of Biological Sciences, University of Wales Swansed, Singleton Park, Swansea SA2 8pp, UK
| | - C J Smith
- Biochemistry Research Group, School of Biological Sciences, University of Wales Swansed, Singleton Park, Swansea SA2 8pp, UK
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42
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Bioactive peptides as signal molecules in plant defense, growth, and development. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s1572-5995(01)80012-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
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Dong H, Beer SV. Riboflavin induces disease resistance in plants by activating a novel signal transduction pathway. PHYTOPATHOLOGY 2000; 90:801-11. [PMID: 18944500 DOI: 10.1094/phyto.2000.90.8.801] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
ABSTRACT The role of riboflavin as an elicitor of systemic resistance and an activator of a novel signaling process in plants was demonstrated. Following treatment with riboflavin, Arabidopsis thaliana developed systemic resistance to Peronospora parasitica and Pseudomonas syringae pv. Tomato, and tobacco developed systemic resistance to Tobacco mosaic virus (TMV) and Alternaria alternata. Riboflavin, at concentrations necessary for resistance induction, did not cause cell death in plants or directly affect growth of the culturable pathogens. Riboflavin induced expression of pathogenesis-related (PR) genes in the plants, suggesting its ability to trigger a signal transduction pathway that leads to systemic resistance. Both the protein kinase inhibitor K252a and mutation in the NIM1/NPR1 gene which controls transcription of defense genes, impaired responsiveness to riboflavin. In contrast, riboflavin induced resistance and PR gene expression in NahG plants, which fail to accumulate salicylic acid (SA). Thus, riboflavin-induced resistance requires protein kinase signaling mechanisms and a functional NIM1/NPR1 gene, but not accumulation of SA. Riboflavin is an elicitor of systemic resistance, and it triggers resistance signal transduction in a distinct manner.
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Govrin EM, Levine A. The hypersensitive response facilitates plant infection by the necrotrophic pathogen Botrytis cinerea. Curr Biol 2000; 10:751-7. [PMID: 10898976 DOI: 10.1016/s0960-9822(00)00560-1] [Citation(s) in RCA: 622] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Plants have evolved efficient mechanisms to combat pathogen attack. One of the earliest responses to attempted pathogen attack is the generation of oxidative burst that can trigger hypersensitive cell death. This is called the hypersensitive response (HR) and is considered to be a major element of plant disease resistance. The HR is thought to deprive the pathogens of a supply of food and confine them to initial infection site. Necrotrophic pathogens, such as the fungi Botrytis cinerea and Sclerotinia sclerotiorum, however, can utilize dead tissue. RESULTS Inoculation of B. cinerea induced an oxidative burst and hypersensitive cell death in Arabidopsis. The degree of B. cinerea and S. sclerotiorum pathogenicity was directly dependent on the level of generation and accumulation of superoxide or hydrogen peroxide. Plant cells exhibited markers of HR death, such as nuclear condensation and induction of the HR-specific gene HSR203J. Growth of B. cinerea was suppressed in the HR-deficient mutant dnd1, and enhanced by HR caused by simultaneous infection with an avirulent strain of the bacterium Pseudomonas syringae. HR had an opposite (inhibitory) effect on a virulent (biotrophic) strain of P. syringae. Moreover, H(2)O(2) levels during HR correlated positively with B. cinerea growth but negatively with growth of virulent P. syringae. CONCLUSIONS We show that, although hypersensitive cell death is efficient against biotrophic pathogens, it does not protect plants against infection by the necrotrophic pathogens B. cinerea and S. sclerotiorum. By contrast, B. cinerea triggers HR, which facilitates its colonization of plants. Hence, these fungi can exploit a host defense mechanism for their pathogenicity.
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Affiliation(s)
- E M Govrin
- Department of Plant Sciences, The Hebrew University of Jerusalem, Givat-Ram, Israel
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Gómez-Gómez L, Boller T. FLS2: an LRR receptor-like kinase involved in the perception of the bacterial elicitor flagellin in Arabidopsis. Mol Cell 2000; 5:1003-11. [PMID: 10911994 DOI: 10.1016/s1097-2765(00)80265-8] [Citation(s) in RCA: 1397] [Impact Index Per Article: 58.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Flagellin, the main protein of the bacterial flagella, elicits defence responses and alters growth in Arabidopsis seedlings. Previously, we identified the FLS1 locus, which confers flagellin insensitivity in Ws-0. To identify additional components involved in flagellin perception, we screened for flagellin insensitivity mutants in the flagellin-sensitive accession La-er. Here, we describe the identification of a new locus, FLS2, by a map-based strategy. The FLS2 gene is ubiquitously expressed and encodes a putative receptor kinase. FLS2 shares structural and functional homologies with known plant resistance genes and with components involved in the innate immune system of mammals and insects.
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46
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Are Plants Stacked Neutrophiles? Comparison of Pathogen-Induced Oxidative Burst in Plants and Mammals. ACTA ACUST UNITED AC 2000. [DOI: 10.1007/978-3-642-57203-6_9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Fritz RS, Moulia C, Newcombe G. Resistance of Hybrid Plants and Animals to Herbivores, Pathogens, and Parasites. ACTA ACUST UNITED AC 1999. [DOI: 10.1146/annurev.ecolsys.30.1.565] [Citation(s) in RCA: 137] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
▪ Abstract Interspecific hybridization can disrupt normal resistance of plant and animal species to their parasites. Resistance to parasites is affected by hybridization in the following ways: no difference between hybrids and parentals, additivity, hybrid susceptibility, and dominance to susceptibility. Similar patterns were seen across host taxa. Responses of different parasite species vary widely to the same hybrid host, which indicates diverse genetic effects of interspecific hybridization on resistance. Differences between field and common garden or laboratory studies suggest that environmental factors in hybrid zones influence the patterns seen in the field. Based on recent studies of hybrid-parasite interactions, three avenues of future research will provide a more complete understanding of the roles of hybrids and the roles of parasites in host evolution. First, the relationship between inheritance of putative resistance mechanisms of hosts and responses of parasites needs study using analyses of recombinant progenies. Second, the interaction among environmental variation in hybrid zones, resistance mechanisms, responses of parasites, and the impact of parasites on host fitness needs experimental analysis using reciprocal transplant experiments in hybrid zones. Finally, the role of hybrids in the community structure and interactions of parasites needs study.
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Affiliation(s)
- Robert S. Fritz
- Department of Biology, Vassar College, Poughkeepsie, New York 12604-0133
| | - Catherine Moulia
- Laboratoire Genome, Populations, Interactions; UPR 9060 CNRS, CC105, UM II Place Eugene Bataillon, Montpellier Cedex O5, France
| | - George Newcombe
- Puyallup Research & Extension Center, Washington State University, Puyallup, Washington 98371-4998 USA
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Piffanelli P, Devoto A, Schulze-Lefert P. Defence signalling pathways in cereals. CURRENT OPINION IN PLANT BIOLOGY 1999; 2:295-300. [PMID: 10459000 DOI: 10.1016/s1369-5266(99)80052-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The combination of mutational and molecular studies has shed light on the role of reactive oxygen intermediates and programmed cell death in cereal disease resistance mechanisms. Rice Rac1 and barley Rar1 represent conserved disease resistance signalling genes, which may have related functions in animals. The analysis of non-pathogenic Magnaporthe grisea mutants may provide novel tools to study host defence pathways.
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Affiliation(s)
- P Piffanelli
- The Sainsbury Laboratory, John Innes Centre, Colney Lane, Norwich, NR4 7UH, UK
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