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Cytokinin Regulates Energy Utilization in Botrytis cinerea. Microbiol Spectr 2022; 10:e0028022. [PMID: 35894612 PMCID: PMC9430538 DOI: 10.1128/spectrum.00280-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
The plant hormone cytokinin (CK) is an important developmental regulator. Previous work has demonstrated that CKs mediate plant immunity and disease resistance. Some phytopathogens have been reported to secrete CKs and may manipulate CK signaling to improve pathogenesis. In recent work, we demonstrated that CK directly inhibits the development and virulence of fungal phytopathogens by attenuating the cell cycle and reducing cytoskeleton organization. Here, focusing on Botrytis cinerea, we report that CK possesses a dual role in fungal biology, with role prioritization being based on sugar availability. In a sugar-rich environment, CK strongly inhibited B. cinerea growth and deregulated cytoskeleton organization. This effect diminished as sugar availability decreased. In its second role, we show using biochemical assays and transgenic redox-sensitive fungal lines that CK can promote glycolysis and energy consumption in B. cinerea, both in vitro and in planta. Glycolysis and increased oxidation mediated by CK were stronger in low sugar availability, indicating that sugar availability could indeed be one possible element determining the role of CK in the fungus. Transcriptomic data further support our findings, demonstrating significant upregulation to glycolysis, oxidative phosphorylation, and sucrose metabolism upon CK treatment. Thus, the effect of CK in fungal biology likely depends on energy status. In addition to the plant producing CK during its interaction with the pathogen for defense priming and pathogen inhibition, the pathogen may take advantage of this increased CK to boost its metabolism and energy production, in preparation for the necrotrophic phase of the infection. IMPORTANCE The hormone cytokinin (CK) is a plant developmental regulator. Previous research has highlighted the involvement of CK in plant defense. Here, we report that CK has a dual role in plant-fungus interactions, inhibiting fungal growth while positively regulating B. cinerea energy utilization, causing an increase in glucose utilization and energy consumption. The effect of CK on B. cinerea was dependent on sugar availability, with CK primarily causing increases in glycolysis when sugar availability was low, and growth inhibition in a high-sugar environment. We propose that CK acts as a signal to the fungus that plant tissue is present, causing it to activate energy metabolism pathways to take advantage of the available food source, while at the same time, CK is employed by the plant to inhibit the attacking pathogen.
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Luo X, Tian T, Bonnave M, Tan X, Huang X, Li Z, Ren M. The Molecular Mechanisms of Phytophthora infestans in Response to Reactive Oxygen Species Stress. PHYTOPATHOLOGY 2021; 111:2067-2079. [PMID: 33787286 DOI: 10.1094/phyto-08-20-0321-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Reactive oxygen species (ROSs) are critical for the growth, development, proliferation, and pathogenicity of microbial pathogens; however, excessive levels of ROSs are toxic. Little is known about the signaling cascades in response to ROS stress in oomycetes such as Phytophthora infestans, the causal agent of potato late blight. Here, P. infestans was used as a model system to investigate the mechanism underlying the response to ROS stress in oomycete pathogens. Results showed severe defects in sporangium germination, mycelium growth, appressorium formation, and virulence of P. infestans in response to H2O2 stress. Importantly, these phenotypes mimic those of P. infestans treated with rapamycin, the inhibitor of target of rapamycin (TOR, 1-phosphatidylinositol-3-kinase). Strong synergism occurred when P. infestans was treated with a combination of H2O2 and rapamycin, suggesting that a crosstalk exists between ROS stress and the TOR signaling pathway. Comprehensive analysis of transcriptome, proteome, and phosphorylation omics showed that H2O2 stress significantly induced the operation of the TOR-mediated autophagy pathway. Monodansylcadaverine staining showed that in the presence of H2O2 and rapamycin, the autophagosome level increased in a dosage-dependent manner. Furthermore, transgenic potatoes containing double-stranded RNA of TOR in P. infestans (PiTOR) displayed high resistance to P. infestans. Therefore, TOR is involved in the ROS response and is a potential target for control of oomycete diseases, because host-mediated silencing of PiTOR increases potato resistance to late blight.
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Affiliation(s)
- Xiumei Luo
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610000, China
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Tingting Tian
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Maxime Bonnave
- Centre for Agriculture and Agro-Industry of Hainaut Province, Ath 7800, Belgium
| | - Xue Tan
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Xiaoqing Huang
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Zhengguo Li
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Maozhi Ren
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610000, China
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou 450000, China
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3
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Kostyuk AI, Panova AS, Kokova AD, Kotova DA, Maltsev DI, Podgorny OV, Belousov VV, Bilan DS. In Vivo Imaging with Genetically Encoded Redox Biosensors. Int J Mol Sci 2020; 21:E8164. [PMID: 33142884 PMCID: PMC7662651 DOI: 10.3390/ijms21218164] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 10/28/2020] [Accepted: 10/29/2020] [Indexed: 12/13/2022] Open
Abstract
Redox reactions are of high fundamental and practical interest since they are involved in both normal physiology and the pathogenesis of various diseases. However, this area of research has always been a relatively problematic field in the context of analytical approaches, mostly because of the unstable nature of the compounds that are measured. Genetically encoded sensors allow for the registration of highly reactive molecules in real-time mode and, therefore, they began a new era in redox biology. Their strongest points manifest most brightly in in vivo experiments and pave the way for the non-invasive investigation of biochemical pathways that proceed in organisms from different systematic groups. In the first part of the review, we briefly describe the redox sensors that were used in vivo as well as summarize the model systems to which they were applied. Next, we thoroughly discuss the biological results obtained in these studies in regard to animals, plants, as well as unicellular eukaryotes and prokaryotes. We hope that this work reflects the amazing power of this technology and can serve as a useful guide for biologists and chemists who work in the field of redox processes.
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Affiliation(s)
- Alexander I. Kostyuk
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Anastasiya S. Panova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Aleksandra D. Kokova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Daria A. Kotova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Dmitry I. Maltsev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Federal Center for Cerebrovascular Pathology and Stroke, 117997 Moscow, Russia
| | - Oleg V. Podgorny
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Vsevolod V. Belousov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
- Federal Center for Cerebrovascular Pathology and Stroke, 117997 Moscow, Russia
- Institute for Cardiovascular Physiology, Georg August University Göttingen, D-37073 Göttingen, Germany
| | - Dmitry S. Bilan
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
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Liu TH, Yaghmour MA, Lee MH, Gradziel TM, Leveau JHJ, Bostock RM. An roGFP2-Based Bacterial Bioreporter for Redox Sensing of Plant Surfaces. PHYTOPATHOLOGY 2020; 110:297-308. [PMID: 31483224 DOI: 10.1094/phyto-07-19-0237-r] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The reduction-oxidation (redox) environment of the phytobiome (i.e., the plant-microbe interface) can strongly influence the outcome of the interaction between microbial pathogens, commensals, and their host. We describe a noninvasive method using a bacterial bioreporter that responds to reactive oxygen species and redox-active chemicals to compare microenvironments perceived by microbes during their initial encounter of the plant surface. A redox-sensitive variant of green fluorescent protein (roGFP2), responsive to changes in intracellular levels of reduced and oxidized glutathione, was expressed under the constitutive SP6 and fruR promoters in the epiphytic bacterium Pantoea eucalypti 299R (Pe299R/roGFP2). Analyses of Pe299R/roGFP2 cells by ratiometric fluorometry showed concentration-dependent responses to several redox active chemicals, including hydrogen peroxide (H2O2), dithiothreitol (DTT), and menadione. Changes in intracellular redox were detected within 5 min of addition of the chemical to Pe299R/roGFP2 cells, with approximate detection limits of 25 and 6 μM for oxidation by H2O2 and menadione, respectively, and 10 μM for reduction by DTT. Caffeic acid, chlorogenic acid, and ascorbic acid mitigated the H2O2-induced oxidation of the roGFP2 bioreporter. Aqueous washes of peach and rose flower petals from young blossoms created a lower redox state in the roGFP2 bioreporter than washes from fully mature blossoms. The bioreporter also detected differences in surface washes from peach fruit at different stages of maturity and between wounded and nonwounded sites. The Pe299R/roGFP2 reporter rapidly assesses differences in redox microenvironments and provides a noninvasive tool that may complement traditional redox-sensitive chromophores and chemical analyses of cell extracts.
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Affiliation(s)
- Ting-Hang Liu
- Department of Plant Pathology, University of California, Davis, CA, U.S.A
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan R.O.C
- NCHU-UCD Plant and Food Biotechnology Center, National Chung Hsing University
- Agricultural Biotechnology Center, National Chung Hsing University
| | | | - Miin-Huey Lee
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan R.O.C
- NCHU-UCD Plant and Food Biotechnology Center, National Chung Hsing University
- Agricultural Biotechnology Center, National Chung Hsing University
| | - Thomas M Gradziel
- Department of Plant Sciences, University of California, Davis, CA, U.S.A
| | - Johan H J Leveau
- Department of Plant Pathology, University of California, Davis, CA, U.S.A
- NCHU-UCD Plant and Food Biotechnology Center, National Chung Hsing University
| | - Richard M Bostock
- Department of Plant Pathology, University of California, Davis, CA, U.S.A
- NCHU-UCD Plant and Food Biotechnology Center, National Chung Hsing University
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5
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Deng H, Bai Y, Fan TP, Zheng X, Cai Y. Advanced strategy for metabolite exploration in filamentous fungi. Crit Rev Biotechnol 2020; 40:180-198. [PMID: 31906740 DOI: 10.1080/07388551.2019.1709798] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Filamentous fungi comprise an abundance of gene clusters that encode high-value metabolites, whereas affluent gene clusters remain silent during laboratory conditions. Complex cellular metabolism further limits these metabolite yields. Therefore, diverse strategies such as genetic engineering and chemical mutagenesis have been developed to activate these cryptic pathways and improve metabolite productivity. However, lower efficiencies of gene modifications and screen tools delayed the above processes. To address the above issues, this review describes an alternative design-construction evaluation optimization (DCEO) approach. The DCEO tool provides theoretical and practical principles to identify potential pathways, modify endogenous pathways, integrate exogenous pathways, and exploit novel pathways for their diverse metabolites and desirable productivities. This DCEO method also offers different tactics to balance the cellular metabolisms, facilitate the genetic engineering, and exploit the scalable metabolites in filamentous fungi.
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Affiliation(s)
- Huaxiang Deng
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China.,Center for Synthetic Biochemistry, Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technologies, Shenzhen, China
| | - Yajun Bai
- College of Life Sciences, Northwest University, Xi'an, Shanxi, China
| | - Tai-Ping Fan
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Xiaohui Zheng
- College of Life Sciences, Northwest University, Xi'an, Shanxi, China
| | - Yujie Cai
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
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6
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Zaffagnini M, Fermani S, Marchand CH, Costa A, Sparla F, Rouhier N, Geigenberger P, Lemaire SD, Trost P. Redox Homeostasis in Photosynthetic Organisms: Novel and Established Thiol-Based Molecular Mechanisms. Antioxid Redox Signal 2019; 31:155-210. [PMID: 30499304 DOI: 10.1089/ars.2018.7617] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Significance: Redox homeostasis consists of an intricate network of reactions in which reactive molecular species, redox modifications, and redox proteins act in concert to allow both physiological responses and adaptation to stress conditions. Recent Advances: This review highlights established and novel thiol-based regulatory pathways underlying the functional facets and significance of redox biology in photosynthetic organisms. In the last decades, the field of redox regulation has largely expanded and this work is aimed at giving the right credit to the importance of thiol-based regulatory and signaling mechanisms in plants. Critical Issues: This cannot be all-encompassing, but is intended to provide a comprehensive overview on the structural/molecular mechanisms governing the most relevant thiol switching modifications with emphasis on the large genetic and functional diversity of redox controllers (i.e., redoxins). We also summarize the different proteomic-based approaches aimed at investigating the dynamics of redox modifications and the recent evidence that extends the possibility to monitor the cellular redox state in vivo. The physiological relevance of redox transitions is discussed based on reverse genetic studies confirming the importance of redox homeostasis in plant growth, development, and stress responses. Future Directions: In conclusion, we can firmly assume that redox biology has acquired an established significance that virtually infiltrates all aspects of plant physiology.
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Affiliation(s)
- Mirko Zaffagnini
- 1 Department of Pharmacy and Biotechnology and University of Bologna, Bologna, Italy
| | - Simona Fermani
- 2 Department of Chemistry Giacomo Ciamician, University of Bologna, Bologna, Italy
| | - Christophe H Marchand
- 3 Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, UMR8226, Centre National de la Recherche Scientifique, Institut de Biologie Physico-Chimique, Sorbonne Université, Paris, France
| | - Alex Costa
- 4 Department of Biosciences, University of Milan, Milan, Italy
| | - Francesca Sparla
- 1 Department of Pharmacy and Biotechnology and University of Bologna, Bologna, Italy
| | | | - Peter Geigenberger
- 6 Department Biologie I, Ludwig-Maximilians-Universität München, LMU Biozentrum, Martinsried, Germany
| | - Stéphane D Lemaire
- 3 Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, UMR8226, Centre National de la Recherche Scientifique, Institut de Biologie Physico-Chimique, Sorbonne Université, Paris, France
| | - Paolo Trost
- 1 Department of Pharmacy and Biotechnology and University of Bologna, Bologna, Italy
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Esposito S, Masala A, Sanna S, Rassu M, Pimxayvong V, Iaccarino C, Crosio C. Redox-sensitive GFP to monitor oxidative stress in neurodegenerative diseases. Rev Neurosci 2018; 28:133-144. [PMID: 28030361 DOI: 10.1515/revneuro-2016-0041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 10/02/2016] [Indexed: 02/06/2023]
Abstract
Redox processes are key events in the degenerative cascade of many adult-onset neurodegenerative diseases (NDs), but the biological relevance of a single redox change is often dependent on the redox couple involved and on its subcellular origin. The biosensors based on engineered fluorescent proteins (redox-sensitive GFP [roGFP]) offer a unique opportunity to monitor redox changes in both physiological and pathological contexts in living animals and plants. Here, we review the use of roGFPs to monitor oxidative stress in different three adult-onset NDs: Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). Despite the many differences spanning from incidence to onset, the hypotheses on biological processes underlying both sporadic and familiar ND forms in humans outline a model in which noncompeting mechanisms are likely to converge in various unsuccessful patterns to mediate the selective degeneration of a specific neuronal population. roGFPs, targeted to different cell compartments, are successfully used as specific markers of cell toxicity, induced by expression of causative genes linked to a determined ND. We also report the use of roGFP to monitor oxidative stress induced by the expression of the ALS-causative gene SOD1.
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8
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Segal LM, Wilson RA. Reactive oxygen species metabolism and plant-fungal interactions. Fungal Genet Biol 2018; 110:1-9. [DOI: 10.1016/j.fgb.2017.12.003] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 12/04/2017] [Accepted: 12/06/2017] [Indexed: 11/26/2022]
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9
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Marschall R, Tudzynski P. The Protein Disulfide Isomerase of Botrytis cinerea: An ER Protein Involved in Protein Folding and Redox Homeostasis Influences NADPH Oxidase Signaling Processes. Front Microbiol 2017; 8:960. [PMID: 28611757 PMCID: PMC5447010 DOI: 10.3389/fmicb.2017.00960] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 05/15/2017] [Indexed: 11/13/2022] Open
Abstract
Botrytis cinerea is a filamentous plant pathogen, which infects hundreds of plant species; within its lifestyle, the production of reactive oxygen species (ROS) and a balanced redox homeostasis are essential parameters. The pathogen is capable of coping with the plant’s oxidative burst and even produces its own ROS to enhance the plant’s oxidative burst. Highly conserved NADPH oxidase (Nox) complexes produce the reactive molecules. The membrane-associated complexes regulate a large variety of vegetative and pathogenic processes. Besides their commonly accepted function at the plasma membrane, recent studies reveal that Nox complexes are also active at the membrane of the endoplasmic reticulum. In this study, we identified the essential ER protein BcPdi1 as new interaction partner of the NoxA complex in B. cinerea. Mutants that lack this ER chaperone display overlapping phenotypes to mutants of the NoxA signaling pathway. The protein appears to be involved in all major developmental processes, such as the formation of sclerotia, conidial anastomosis tubes and infection cushions (IC’s) and is needed for full virulence. Moreover, expression analyses and reporter gene studies indicate that BcPdi1 affects the redox homeostasis and unfolded protein response (UPR)-related genes. Besides the close association between BcPdi1 and BcNoxA, interaction studies provide evidence that the ER protein might likewise be involved in Ca2+ regulated processes. Finally, we were able to show that the potential key functions of the protein BcPdi1 might be affected by its phosphorylation state.
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Affiliation(s)
- Robert Marschall
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität MünsterMünster, Germany
| | - Paul Tudzynski
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität MünsterMünster, Germany
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Zhou TT, Zhao YL, Guo HS. Secretory proteins are delivered to the septin-organized penetration interface during root infection by Verticillium dahliae. PLoS Pathog 2017; 13:e1006275. [PMID: 28282450 PMCID: PMC5362242 DOI: 10.1371/journal.ppat.1006275] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 03/22/2017] [Accepted: 03/07/2017] [Indexed: 01/02/2023] Open
Abstract
Successful infection of the host requires secretion of effector proteins to evade or suppress plant immunity. Secretion of effectors in root-infecting fungal pathogens, however, remains unexplored. We previously reported that Verticillium dahliae, a root-infecting phytopathogenic fungus, develops a penetration peg from a hyphopodium to infect cotton roots. In this study, we report that a septin ring, requiring VdSep5, partitions the hyphopodium and the invasive hypha and form the specialized fungus-host interface. The mutant strain, VdΔnoxb, in which NADPH oxidase B (VdNoxB) is deleted, impaired formation of the septin ring at the hyphal neck, indicating that NADPH oxidases regulate septin ring organization. Using GFP tagging and live cell imaging, we observed that several signal peptide containing secreted proteins showed ring signal accumulation/secretion at the penetration interface surrounding the hyphal neck. Targeted mutation for VdSep5 reduced the delivery rate of secretory proteins to the penetration interface. Blocking the secretory pathway by disrupting the vesicular trafficking factors, VdSec22 and VdSyn8, or the exocyst subunit, VdExo70, also arrested delivery of the secreted proteins inside the hyphopodium. Reduced virulence was observed when cotton roots were infected with VdΔsep5, VdΔsec22, VdΔsyn8 and VdΔexo70 mutants compared to infection with the isogenic wild-type V592. Taken together, our data demonstrate that the hyphal neck is an important site for protein secretion during plant root infection, and that the multiple secretory routes are involved in the secretion. Pathogens secrete effector proteins as molecular weapons to evade or suppress plant immunity. However, the mechanism(s) by which root-infecting fungal pathogens secrete secretory effector proteins remains unexplored. We previously reported that Verticillium dahliae, a root-infecting phytopathogenic fungus, forms a specialized infection structure known as a hyphopodium that develops a penetration peg to pierce plant roots. In this study, we observed that after penetration, the penetration peg-developed hyphal neck, partitioning the hyphopodium and invasive hypha, came into close contact with the host, forming the fungus-host penetration interface. NADPH oxidase B (VdNoxB) regulated the cytoskeletal organization of the septin ring at the hyphal neck. Importantly, the penetration interface was a preferential site for secretion of signal peptide-containing proteins. Septin plays an important role in the efficient delivery of secretory proteins to the penetration interface. Moreover, the conventional fungal ER-to-Golgi secretion pathway, endosome-mediated transport and the exocyst complex are involved in the delivery of secretory proteins to the penetration interface. Together, our data demonstrate that the V. dahliae infection structure functions as a key signaling hub during plant infection and is the apparatus that not only breaches host cells but also provides a unique interface for the secretion of fungal effectors.
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Affiliation(s)
- Ting-Ting Zhou
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of the Chinese Academy of Sciences, Beijing, China
| | - Yun-Long Zhao
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of the Chinese Academy of Sciences, Beijing, China
| | - Hui-Shan Guo
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of the Chinese Academy of Sciences, Beijing, China
- * E-mail:
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Huang K, Caplan J, Sweigard JA, Czymmek KJ, Donofrio NM. Optimization of the HyPer sensor for robust real-time detection of hydrogen peroxide in the rice blast fungus. MOLECULAR PLANT PATHOLOGY 2017; 18:298-307. [PMID: 26950262 PMCID: PMC6638257 DOI: 10.1111/mpp.12392] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Reactive oxygen species (ROS) production and breakdown have been studied in detail in plant-pathogenic fungi, including the rice blast fungus, Magnaporthe oryzae; however, the examination of the dynamic process of ROS production in real time has proven to be challenging. We resynthesized an existing ROS sensor, called HyPer, to exhibit optimized codon bias for fungi, specifically Neurospora crassa, and used a combination of microscopy and plate reader assays to determine whether this construct could detect changes in fungal ROS during the plant infection process. Using confocal microscopy, we were able to visualize fluctuating ROS levels during the formation of an appressorium on an artificial hydrophobic surface, as well as during infection on host leaves. Using the plate reader, we were able to ascertain measurements of hydrogen peroxide (H2 O2 ) levels in conidia as detected by the MoHyPer sensor. Overall, by the optimization of codon usage for N. crassa and related fungal genomes, the MoHyPer sensor can be used as a robust, dynamic and powerful tool to both monitor and quantify H2 O2 dynamics in real time during important stages of the plant infection process.
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Affiliation(s)
- Kun Huang
- BioImaging CenterDelaware Biotechnology InstituteNewarkDE 19716USA
- Department of Plant and Soil SciencesUniversity of DelawareNewarkDE19716USA
| | - Jeff Caplan
- BioImaging CenterDelaware Biotechnology InstituteNewarkDE 19716USA
| | - James A. Sweigard
- DuPont Stine Haskell Research Center 1090 Elkton RdNewarkDE 19711USA
| | | | - Nicole M. Donofrio
- Department of Plant and Soil SciencesUniversity of DelawareNewarkDE19716USA
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12
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Marschall R, Siegmund U, Burbank J, Tudzynski P. Update on Nox function, site of action and regulation in Botrytis cinerea. Fungal Biol Biotechnol 2016; 3:8. [PMID: 28955467 PMCID: PMC5611593 DOI: 10.1186/s40694-016-0026-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 09/29/2016] [Indexed: 12/11/2022] Open
Abstract
Background The production of reactive oxygen species (ROS) and a balanced redox homeostasis are essential parameters, which control the infection process of the plant pathogen Botrytis cinerea. The necrotrophic fungus is able to cope with the plants’ oxidative burst and even produces its own ROS to overcome the plants’ defense barrier. Major enzyme complexes, which are responsible for the production of superoxide, are NADPH oxidase (Nox) complexes. They play a central role in various growth, differentiation and pathogenic processes. However, information about their regulation and the integration in the complex signaling network of filamentous fungi is still scarce. Results In this work, we give an update on Nox structure, function, site of action and regulation. We show that functionality of the catalytic Nox-subunits seems to be independent from their transcriptional regulation and that the membrane orientation of BcNoxA would allow electron transport inside the ER. Following previous studies, which provided evidence for distinct functions of the NoxA complex inside the ER, we highlight in this work that the N-terminus of BcNoxA is essential for these functions. Finally, we elucidate the role of BcNoxD and BcNoxB inside the ER by complementing the deletion mutants with ER bound alleles. Conclusions This study provides a deeper analysis of the Nox complexes in B. cinerea. Besides new insights in the overall regulation of the complexes, we provide further evidence that the NoxA complex has a predominant role inside the ER, while the NoxB complex is mainly important outside the ER, likely at the plasma membrane. By considering all other putative Nox complex members, we propose a putative model, which describes the distinct complex pattern upon certain differentiation processes. Electronic supplementary material The online version of this article (doi:10.1186/s40694-016-0026-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Robert Marschall
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms Universität, Schlossplatz 8, 48143 Münster, Germany
| | - Ulrike Siegmund
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms Universität, Schlossplatz 8, 48143 Münster, Germany
| | - Joachim Burbank
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms Universität, Schlossplatz 8, 48143 Münster, Germany
| | - Paul Tudzynski
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms Universität, Schlossplatz 8, 48143 Münster, Germany
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Belmondo S, Marschall R, Tudzynski P, López Ráez JA, Artuso E, Prandi C, Lanfranco L. Identification of genes involved in fungal responses to strigolactones using mutants from fungal pathogens. Curr Genet 2016; 63:201-213. [DOI: 10.1007/s00294-016-0626-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 06/20/2016] [Accepted: 06/21/2016] [Indexed: 11/30/2022]
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Schwarzländer M, Dick TP, Meyer AJ, Morgan B. Dissecting Redox Biology Using Fluorescent Protein Sensors. Antioxid Redox Signal 2016; 24:680-712. [PMID: 25867539 DOI: 10.1089/ars.2015.6266] [Citation(s) in RCA: 191] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
SIGNIFICANCE Fluorescent protein sensors have revitalized the field of redox biology by revolutionizing the study of redox processes in living cells and organisms. RECENT ADVANCES Within one decade, a set of fundamental new insights has been gained, driven by the rapid technical development of in vivo redox sensing. Redox-sensitive yellow and green fluorescent protein variants (rxYFP and roGFPs) have been the central players. CRITICAL ISSUES Although widely used as an established standard tool, important questions remain surrounding their meaningful use in vivo. We review the growing range of thiol redox sensor variants and their application in different cells, tissues, and organisms. We highlight five key findings where in vivo sensing has been instrumental in changing our understanding of redox biology, critically assess the interpretation of in vivo redox data, and discuss technical and biological limitations of current redox sensors and sensing approaches. FUTURE DIRECTIONS We explore how novel sensor variants may further add to the current momentum toward a novel mechanistic and integrated understanding of redox biology in vivo. Antioxid. Redox Signal. 24, 680-712.
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Affiliation(s)
- Markus Schwarzländer
- 1 Plant Energy Biology Lab, Department Chemical Signalling, Institute of Crop Science and Resource Conservation (INRES), University of Bonn , Bonn, Germany
| | - Tobias P Dick
- 2 Division of Redox Regulation, German Cancer Research Center (DKFZ) , DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Andreas J Meyer
- 3 Department Chemical Signalling, Institute of Crop Science and Resource Conservation (INRES), University of Bonn , Bonn, Germany
| | - Bruce Morgan
- 2 Division of Redox Regulation, German Cancer Research Center (DKFZ) , DKFZ-ZMBH Alliance, Heidelberg, Germany .,4 Cellular Biochemistry, Department of Biology, University of Kaiserslautern , Kaiserslautern, Germany
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Marschall R, Tudzynski P. Reactive oxygen species in development and infection processes. Semin Cell Dev Biol 2016; 57:138-146. [PMID: 27039026 DOI: 10.1016/j.semcdb.2016.03.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 03/29/2016] [Accepted: 03/29/2016] [Indexed: 12/31/2022]
Abstract
Reactive oxygen species (ROS) are important signaling molecules that affect vegetative and pathogenic processes in pathogenic fungi. There is growing evidence that ROS are not only secreted during the interaction of host and pathogen but also involved in tightly controlled intracellular processes. The major ROS producing enzymes are NADPH oxidases (Nox). Recent investigations in fungi revealed that Nox-activity is responsible for the formation of infection structures, cytoskeleton architecture as well as interhyphal communication. However, information about the localization and site of action of the Nox complexes in fungi is limited and signaling pathways and intracellular processes affected by ROS have not been fully elucidated. This review focuses on the role of ROS as signaling molecules in fungal "model" organisms: it examines the role of ROS in vegetative and pathogenic processes and gives special attention to Nox complexes and their function as important signaling hubs.
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Affiliation(s)
- Robert Marschall
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms Universität, Schlossplatz 8, D-48143 Münster, Germany
| | - Paul Tudzynski
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms Universität, Schlossplatz 8, D-48143 Münster, Germany.
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Chasing stress signals - Exposure to extracellular stimuli differentially affects the redox state of cell compartments in the wild type and signaling mutants of Botrytis cinerea. Fungal Genet Biol 2016; 90:12-22. [PMID: 26988904 DOI: 10.1016/j.fgb.2016.03.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 02/26/2016] [Accepted: 03/13/2016] [Indexed: 10/22/2022]
Abstract
Reactive oxygen species (ROS) are important molecules influencing intracellular developmental processes as well as plant pathogen interactions. They are produced at the infection site and affect the intracellular redox homeostasis. However, knowledge of ROS signaling pathways, their connection to other signaling cascades, and tools for the visualization of intra- and extracellular ROS levels and their impact on the redox state are scarce. By using the genetically encoded biosensor roGFP2 we studied for the first time the differences between the redox states of the cytosol, the intermembrane space of mitochondria and the ER in the filamentous fungus Botrytis cinerea. We showed that the ratio of oxidized to reduced glutathione inside of the cellular compartments differ and that the addition of hydrogen peroxide (H2O2), calcium chloride (CaCl2) and the fluorescent dye calcofluor white (CFW) have a direct impact on the cellular redox states. Dependent on the type of stress agents applied, the redox states were affected in the different cellular compartments in a temporally shifted manner. By integrating the biosensor in deletion mutants of bcnoxA, bcnoxB, bctrx1 and bcltf1 we further elucidated the putative roles of the different proteins in distinct stress-response pathways. We showed that the redox states of ΔbcnoxA and ΔbcnoxB display a wild-type pattern upon exposure to H2O2, but appear to be strongly affected by CaCl2 and CFW. Moreover, we demonstrated the involvement of the light-responsive transcription factor BcLtf1 in the maintenance of the redox state in the intermembrane space of the mitochondria. Finally, we report that CaCl2 as well as cell wall stress-inducing agents stimulate ROS production and that ΔbcnoxB produces significantly less ROS than the wild type and ΔbcnoxA.
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Anderson JP, Hane JK, Stoll T, Pain N, Hastie ML, Kaur P, Hoogland C, Gorman JJ, Singh KB. Proteomic Analysis of Rhizoctonia solani Identifies Infection-specific, Redox Associated Proteins and Insight into Adaptation to Different Plant Hosts. Mol Cell Proteomics 2016; 15:1188-203. [PMID: 26811357 PMCID: PMC4824849 DOI: 10.1074/mcp.m115.054502] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Indexed: 11/22/2022] Open
Abstract
Rhizoctonia solani is an important root infecting pathogen of a range of food staples worldwide including wheat, rice, maize, soybean, potato and others. Conventional resistance breeding strategies are hindered by the absence of tractable genetic resistance in any crop host. Understanding the biology and pathogenicity mechanisms of this fungus is important for addressing these disease issues, however, little is known about how R. solani causes disease. This study capitalizes on recent genomic studies by applying mass spectrometry based proteomics to identify soluble, membrane-bound and culture filtrate proteins produced under wheat infection and vegetative growth conditions. Many of the proteins found in the culture filtrate had predicted functions relating to modification of the plant cell wall, a major activity required for pathogenesis on the plant host, including a number found only under infection conditions. Other infection related proteins included a high proportion of proteins with redox associated functions and many novel proteins without functional classification. The majority of infection only proteins tested were confirmed to show transcript up-regulation during infection including a thaumatin which increased susceptibility to R. solani when expressed in Nicotiana benthamiana. In addition, analysis of expression during infection of different plant hosts highlighted how the infection strategy of this broad host range pathogen can be adapted to the particular host being encountered. Data are available via ProteomeXchange with identifier PXD002806.
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Affiliation(s)
- Jonathan P Anderson
- From the ‡CSIRO Agriculture, Floreat, Western Australia; §The University of Western Australia Institute of Agriculture, Crawley, Western Australia
| | - James K Hane
- From the ‡CSIRO Agriculture, Floreat, Western Australia
| | - Thomas Stoll
- ¶QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Nicholas Pain
- From the ‡CSIRO Agriculture, Floreat, Western Australia
| | - Marcus L Hastie
- ¶QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | | | | | - Jeffrey J Gorman
- ¶QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Karam B Singh
- From the ‡CSIRO Agriculture, Floreat, Western Australia; §The University of Western Australia Institute of Agriculture, Crawley, Western Australia;
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Mentges M, Bormann J. Real-time imaging of hydrogen peroxide dynamics in vegetative and pathogenic hyphae of Fusarium graminearum. Sci Rep 2015; 5:14980. [PMID: 26446493 PMCID: PMC4597226 DOI: 10.1038/srep14980] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 09/15/2015] [Indexed: 01/17/2023] Open
Abstract
Balanced dynamics of reactive oxygen species in the phytopathogenic fungus Fusarium graminearum play key roles for development and infection. To monitor those dynamics, ratiometric analysis using the novel hydrogen peroxide (H2O2) sensitive fluorescent indicator protein HyPer-2 was established for the first time in phytopathogenic fungi. H2O2 changes the excitation spectrum of HyPer-2 with an excitation maximum at 405 nm for the reduced and 488 nm for the oxidized state, facilitating ratiometric readouts with maximum emission at 516 nm. HyPer-2 analyses were performed using a microtiter fluorometer and confocal laser scanning microscopy (CLSM). Addition of external H2O2 to mycelia caused a steep and transient increase in fluorescence excited at 488 nm. This can be reversed by the addition of the reducing agent dithiothreitol. HyPer-2 in F. graminearum is highly sensitive and specific to H2O2 even in tiny amounts. Hyperosmotic treatment elicited a transient internal H2O2 burst. Hence, HyPer-2 is suitable to monitor the intracellular redox balance. Using CLSM, developmental processes like nuclear division, tip growth, septation, and infection structure development were analyzed. The latter two processes imply marked accumulations of intracellular H2O2. Taken together, HyPer-2 is a valuable and reliable tool for the analysis of environmental conditions, cellular development, and pathogenicity.
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Affiliation(s)
- Michael Mentges
- University of Hamburg, Biocenter Klein Flottbek, Department of Molecular Phytopathology and Genetics, Ohnhorststr. 18, D-22609 Hamburg, Germany
| | - Jörg Bormann
- University of Hamburg, Biocenter Klein Flottbek, Department of Molecular Phytopathology and Genetics, Ohnhorststr. 18, D-22609 Hamburg, Germany
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Mir AA, Park SY, Abu Sadat M, Kim S, Choi J, Jeon J, Lee YH. Systematic characterization of the peroxidase gene family provides new insights into fungal pathogenicity in Magnaporthe oryzae. Sci Rep 2015; 5:11831. [PMID: 26134974 PMCID: PMC4488832 DOI: 10.1038/srep11831] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 06/04/2015] [Indexed: 11/14/2022] Open
Abstract
Fungal pathogens have evolved antioxidant defense against reactive oxygen species produced as a part of host innate immunity. Recent studies proposed peroxidases as components of antioxidant defense system. However, the role of fungal peroxidases during interaction with host plants has not been explored at the genomic level. Here, we systematically identified peroxidase genes and analyzed their impact on fungal pathogenesis in a model plant pathogenic fungus, Magnaporthe oryzae. Phylogeny reconstruction placed 27 putative peroxidase genes into 15 clades. Expression profiles showed that majority of them are responsive to in planta condition and in vitro H2O2. Our analysis of individual deletion mutants for seven selected genes including MoPRX1 revealed that these genes contribute to fungal development and/or pathogenesis. We identified significant and positive correlations among sensitivity to H2O2, peroxidase activity and fungal pathogenicity. In-depth analysis of MoPRX1 demonstrated that it is a functional ortholog of thioredoxin peroxidase in Saccharomyces cerevisiae and is required for detoxification of the oxidative burst within host cells. Transcriptional profiling of other peroxidases in ΔMoprx1 suggested interwoven nature of the peroxidase-mediated antioxidant defense system. The results from this study provide insight into the infection strategy built on evolutionarily conserved peroxidases in the rice blast fungus.
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Affiliation(s)
- Albely Afifa Mir
- Department of Agricultural Biotechnology, Fungal Bioinformatics Laboratory, Center for Fungal Genetic Resources, and Center for Fungal Pathogenesis, Seoul National University, Seoul 151-921, Korea
| | - Sook-Young Park
- Department of Agricultural Biotechnology, Fungal Bioinformatics Laboratory, Center for Fungal Genetic Resources, and Center for Fungal Pathogenesis, Seoul National University, Seoul 151-921, Korea
| | - Md Abu Sadat
- Department of Agricultural Biotechnology, Fungal Bioinformatics Laboratory, Center for Fungal Genetic Resources, and Center for Fungal Pathogenesis, Seoul National University, Seoul 151-921, Korea
| | - Seongbeom Kim
- Department of Agricultural Biotechnology, Fungal Bioinformatics Laboratory, Center for Fungal Genetic Resources, and Center for Fungal Pathogenesis, Seoul National University, Seoul 151-921, Korea
| | - Jaeyoung Choi
- Department of Agricultural Biotechnology, Fungal Bioinformatics Laboratory, Center for Fungal Genetic Resources, and Center for Fungal Pathogenesis, Seoul National University, Seoul 151-921, Korea
| | - Junhyun Jeon
- Department of Agricultural Biotechnology, Fungal Bioinformatics Laboratory, Center for Fungal Genetic Resources, and Center for Fungal Pathogenesis, Seoul National University, Seoul 151-921, Korea
| | - Yong-Hwan Lee
- Department of Agricultural Biotechnology, Fungal Bioinformatics Laboratory, Center for Fungal Genetic Resources, and Center for Fungal Pathogenesis, Seoul National University, Seoul 151-921, Korea
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20
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Unraveling the Function of the Response Regulator BcSkn7 in the Stress Signaling Network of Botrytis cinerea. EUKARYOTIC CELL 2015; 14:636-51. [PMID: 25934690 DOI: 10.1128/ec.00043-15] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 04/24/2015] [Indexed: 12/25/2022]
Abstract
Important for the lifestyle and survival of every organism is the ability to respond to changing environmental conditions. The necrotrophic plant pathogen Botrytis cinerea triggers an oxidative burst in the course of plant infection and therefore needs efficient signal transduction to cope with this stress. The factors involved in this process and their precise roles are still not well known. Here, we show that the transcription factor Bap1 and the response regulator (RR) B. cinerea Skn7 (BcSkn7) are two key players in the oxidative stress response (OSR) of B. cinerea; both have a major influence on the regulation of classical OSR genes. A yeast-one-hybrid (Y1H) approach proved direct binding to the promoters of gsh1 and grx1 by Bap1 and of glr1 by BcSkn7. While the function of Bap1 is restricted to the regulation of oxidative stress, analyses of Δbcskn7 mutants revealed functions beyond the OSR. Involvement of BcSkn7 in development and virulence could be demonstrated, indicated by reduced vegetative growth, impaired formation of reproductive structures, and reduced infection cushion-mediated penetration of the host by the mutants. Furthermore, Δbcskn7 mutants were highly sensitive to oxidative, osmotic, and cell wall stress. Analyses of Δbap1 bcskn7 double mutants indicated that loss of BcSkn7 uncovers an underlying phenotype of Bap1. In contrast to Saccharomyces cerevisiae, the ortholog of the glutathione peroxidase Gpx3p is not required for nuclear translocation of Bap1. The presented results contribute to the understanding of the OSR in B. cinerea and prove that it differs substantially from that of yeast, demonstrating the complexity and versatility of components involved in signaling pathways.
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Lehmann S, Serrano M, L'Haridon F, Tjamos SE, Metraux JP. Reactive oxygen species and plant resistance to fungal pathogens. PHYTOCHEMISTRY 2015; 112:54-62. [PMID: 25264341 DOI: 10.1016/j.phytochem.2014.08.027] [Citation(s) in RCA: 152] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 08/18/2014] [Accepted: 08/28/2014] [Indexed: 05/18/2023]
Abstract
Reactive oxygen species (ROS) have been studied for their role in plant development as well as in plant immunity. ROS were consistently observed to accumulate in the plant after the perception of pathogens and microbes and over the years, ROS were postulated to be an integral part of the defence response of the plant. In this article we will focus on recent findings about ROS involved in the interaction of plants with pathogenic fungi. We will describe the ways to detect ROS, their modes of action and their importance in relation to resistance to fungal pathogens. In addition we include some results from works focussing on the fungal interactor and from studies investigating roots during pathogen attack.
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Affiliation(s)
- Silke Lehmann
- Department of Biology, University of Fribourg, 10 chemin du Musée, CH-1700 Fribourg, Switzerland.
| | - Mario Serrano
- Department of Biology, University of Fribourg, 10 chemin du Musée, CH-1700 Fribourg, Switzerland.
| | - Floriane L'Haridon
- Department of Biology, University of Fribourg, 10 chemin du Musée, CH-1700 Fribourg, Switzerland.
| | - Sotirios E Tjamos
- Laboratory of Plant Pathology, Department of Crop Science, Agricultural University of Athens, 75 Iera Odos, 118 55 Athens, Greece.
| | - Jean-Pierre Metraux
- Department of Biology, University of Fribourg, 10 chemin du Musée, CH-1700 Fribourg, Switzerland.
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Viefhues A, Heller J, Temme N, Tudzynski P. Redox systems in Botrytis cinerea: impact on development and virulence. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:858-74. [PMID: 24983673 DOI: 10.1094/mpmi-01-14-0012-r] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The thioredoxin system is of great importance for maintenance of cellular redox homeostasis. Here, we show that it has a severe influence on virulence of Botrytis cinerea, demonstrating that redox processes are important for host-pathogen interactions in this necrotrophic plant pathogen. The thioredoxin system is composed of two enzymes, the thioredoxin and the thioredoxin reductase. We identified two genes encoding for thioredoxins (bctrx1, bctrx2) and one gene encoding for a thioredoxin reductase (bctrr1) in the genome of B. cinerea. Knockout mutants of bctrx1 and bctrr1 were severely impaired in virulence and more sensitive to oxidative stress. Additionally, Δbctrr1 showed enhanced H2O2 production and retarded growth. To investigate the impact of the second major cellular redox system, glutathione, we generated deletion mutants for two glutathione reductase genes. The effects were only marginal; deletion of bcglr1 resulted in reduced germination and, correspondingly, to retarded infection as well as reduced growth on minimal medium, whereas bcglr2 deletion had no distinctive phenotype. In summary, we showed that the balanced redox status maintained by the thioredoxin system is essential for development and pathogenesis of B. cinerea, whereas the second major cellular redox system, the glutathione system, seems to have only minor impact on these processes.
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The transcription factor BcLTF1 regulates virulence and light responses in the necrotrophic plant pathogen Botrytis cinerea. PLoS Genet 2014; 10:e1004040. [PMID: 24415947 PMCID: PMC3886904 DOI: 10.1371/journal.pgen.1004040] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 11/01/2013] [Indexed: 01/16/2023] Open
Abstract
Botrytis cinerea is the causal agent of gray mold diseases in a range of dicotyledonous plant species. The fungus can reproduce asexually by forming macroconidia for dispersal and sclerotia for survival; the latter also participate in sexual reproduction by bearing the apothecia after fertilization by microconidia. Light induces the differentiation of conidia and apothecia, while sclerotia are exclusively formed in the absence of light. The relevance of light for virulence of the fungus is not obvious, but infections are observed under natural illumination as well as in constant darkness. By a random mutagenesis approach, we identified a novel virulence-related gene encoding a GATA transcription factor (BcLTF1 for light-responsive TF1) with characterized homologues in Aspergillus nidulans (NsdD) and Neurospora crassa (SUB-1). By deletion and over-expression of bcltf1, we confirmed the predicted role of the transcription factor in virulence, and discovered furthermore its functions in regulation of light-dependent differentiation, the equilibrium between production and scavenging of reactive oxygen species (ROS), and secondary metabolism. Microarray analyses revealed 293 light-responsive genes, and that the expression levels of the majority of these genes (66%) are modulated by BcLTF1. In addition, the deletion of bcltf1 affects the expression of 1,539 genes irrespective of the light conditions, including the overexpression of known and so far uncharacterized secondary metabolism-related genes. Increased expression of genes encoding alternative respiration enzymes, such as the alternative oxidase (AOX), suggest a mitochondrial dysfunction in the absence of bcltf1. The hypersensitivity of Δbctlf1 mutants to exogenously applied oxidative stress - even in the absence of light - and the restoration of virulence and growth rates in continuous light by antioxidants, indicate that BcLTF1 is required to cope with oxidative stress that is caused either by exposure to light or arising during host infection. Both fungal pathogens and their host plants respond to light, which represents an important environmental cue. Unlike plants using light for energy generation, filamentous fungi use light, or its absence, as a general signal for orientation (night/day, underground/on the surface). Therefore, dependent on the ecological niche of the fungus, light may control the development of reproductive structures (photomorphogenesis), the dispersal of propagules (phototropism of reproductive structures) and the circadian rhythm. As in other organisms, fungi have to protect themselves against the detrimental effects of light, i.e. the damage to macromolecules by emerging singlet oxygen. Adaptive responses are the accumulation of pigments, especially in the reproductive and survival structures such as spores, sclerotia and fruiting bodies. Light is sensed by fungal photoreceptors leading to quick responses on the transcriptional level, and is furthermore considered to result in the accumulation of reactive oxygen species (ROS). In this study, we provide evidence that an unbalanced ROS homoeostasis (generation outweighs detoxification) caused by the deletion of the light-responsive transcription factor BcLTF1 impairs the ability of the necrotrophic pathogen Botrytis cinerea to grow in the presence of additional oxidative stress arising during illumination or during infection of the host.
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Samalova M, Meyer AJ, Gurr SJ, Fricker MD. Robust anti-oxidant defences in the rice blast fungus Magnaporthe oryzae confer tolerance to the host oxidative burst. THE NEW PHYTOLOGIST 2014; 201:556-573. [PMID: 24117971 DOI: 10.1111/nph.12530] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 08/20/2013] [Indexed: 05/22/2023]
Abstract
Plants respond to pathogen attack via a rapid burst of reactive oxygen species (ROS). However, ROS are also produced by fungal metabolism and are required for the development of infection structures in Magnaporthe oryzae. To obtain a better understanding of redox regulation in M. oryzae, we measured the amount and redox potential of glutathione (E(GSH)), as the major cytoplasmic anti-oxidant, the rates of ROS production, and mitochondrial activity using multi-channel four-dimensional (x,y,z,t) confocal imaging of Grx1-roGFP2 and fluorescent reporters during spore germination, appressorium formation and infection. High levels of mitochondrial activity and ROS were localized to the growing germ tube and appressorium, but E(GSH) was highly reduced and tightly regulated during development. Furthermore, germlings were extremely resistant to external H2O2 exposure ex planta. EGSH remained highly reduced during successful infection of the susceptible rice cultivar CO39. By contrast, there was a dramatic reduction in the infection of resistant (IR68) rice, but the sparse hyphae that did form also maintained a similar reduced E(GSH). We conclude that M. oryzae has a robust anti-oxidant defence system and maintains tight control of EGSH despite substantial oxidative challenge. Furthermore, the magnitude of the host oxidative burst alone does not stress the pathogen sufficiently to prevent infection in this pathosystem.
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Affiliation(s)
- Marketa Samalova
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Andreas J Meyer
- INRES, Universität Bonn, Friedrich-Ebert-Allee 144, D-53113, Bonn, Germany
| | - Sarah J Gurr
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
- Biosciences, University of Exeter, Devon, EX4 4QD, UK
| | - Mark D Fricker
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
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Ronen M, Shalaby S, Horwitz BA. Role of the transcription factor ChAP1 in cytoplasmic redox homeostasis: imaging with a genetically encoded sensor in the maize pathogen Cochliobolus heterostrophus. MOLECULAR PLANT PATHOLOGY 2013; 14:786-90. [PMID: 23745603 PMCID: PMC6638657 DOI: 10.1111/mpp.12047] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The redox-sensitive transcription factor ChAP1 [Cochliobolus heterostrophus YAP1 (Yeast Activator Protein 1) orthologue] of C. heterostrophus is required for oxidative stress tolerance. It is not known, however, to what extent the intracellular redox state changes on exposure of the fungus to oxidants, and whether ChAP1 is involved in the return of the cell to redox homeostasis. In order to answer these questions, we expressed a ratiometric redox-sensitive fluorescent protein sensor, pHyper, in C. heterostrophus. The fluorescence ratio was sensitive to extracellular hydrogen peroxide (H2O2) concentrations that had been shown previously to inhibit the germination of conidia and growth of the pathogen in culture. chap1 mutants showed a slower return to redox homeostasis than the wild-type on exposure to H2O2. Plant extracts that mimic oxidants in their ability to promote nuclear retention of ChAP1 reduced, rather than oxidized, the fungal cells. This result is consistent with other data suggesting that ChAP1 responds to plant-derived signals other than oxidants. pHyper should be a useful reporter of the intracellular redox state in filamentous fungi.
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Affiliation(s)
- Mordechai Ronen
- Department of Plant Sciences, Tel Aviv University, Ramat Aviv 69978, Israel
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Tudzynski P, Heller J, Siegmund U. Reactive oxygen species generation in fungal development and pathogenesis. Curr Opin Microbiol 2012; 15:653-9. [PMID: 23123514 DOI: 10.1016/j.mib.2012.10.002] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 10/01/2012] [Accepted: 10/01/2012] [Indexed: 12/20/2022]
Abstract
Reactive oxygen species (ROS) generated by NADPH-dependent oxidases (Nox) have been shown to function as signaling molecules and to be essential for many differentiation processes in mammals and plants. There is growing evidence that ROS are important for many aspects of fungal life including vegetative hyphal growth, differentiation of conidial anastomosis tubes, fruiting body and infection structure formation, and for induction of apoptosis. Recent results from studies in fungal saprophytic and pathogenic model systems have shed new light on the role of Nox in cytoskeleton organization, the structure of Nox complexes and links to components of the apical complex, and the localization of Nox to the endoplasmic reticulum.
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Affiliation(s)
- Paul Tudzynski
- Institut für Biologie und Biotechnologie der Pflanzen, Westf. Wilhelms Universitaet, Schlossplatz 8, D-48143 Muenster, Germany.
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