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Stapley J, McDonald BA. Quantitative trait locus mapping of osmotic stress response in the fungal wheat pathogen Zymoseptoria tritici. G3 (BETHESDA, MD.) 2023; 13:jkad226. [PMID: 37774498 PMCID: PMC10700024 DOI: 10.1093/g3journal/jkad226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 10/01/2023]
Abstract
Osmotic stress is a ubiquitous and potent stress for all living organisms, but few studies have investigated the genetic basis of salt tolerance in filamentous fungi. The main aim of this study was to identify regions of the genome associated with tolerance to potassium chloride (KCl) in the wheat pathogen Zymoseptoria tritici. A secondary aim was to identify candidate genes affecting salt tolerance within the most promising chromosomal regions. We achieved these aims with a quantitative trait locus (QTL) mapping study using offspring from 2 crosses grown in vitro in the presence or absence of osmotic stress imposed by 0.75 M KCl. We identified significant QTL for most of the traits in both crosses. Several QTLs overlapped with QTL identified in earlier studies for other traits, and some QTL explained trait variation in both the control and salt stress environments. A significant QTL on chromosome 3 explained variation in colony radius at 8-day postinoculation (dpi) in the KCl environment as well as colony radius KCl tolerance at 8 dpi. The QTL peak had a high logarithm of the odds ratio (LOD) and encompassed an interval containing only 36 genes. Six of these genes present promising candidates for functional analyses. A gene ontology (GO) enrichment analysis of QTL unique to the KCl environment found evidence for the enrichment of functions involved in osmotic stress responses.
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Affiliation(s)
- Jessica Stapley
- Plant Pathology Group, Institute of Integrative Biology, ETH Zurich, Zürich 8092, Switzerland
| | - Bruce A McDonald
- Plant Pathology Group, Institute of Integrative Biology, ETH Zurich, Zürich 8092, Switzerland
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2
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Umar A. Screening and evaluation of laccase produced by different Trichoderma species along with their phylogenetic relationship. Arch Microbiol 2021; 203:4319-4327. [PMID: 34110483 DOI: 10.1007/s00203-021-02420-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 05/29/2021] [Accepted: 06/01/2021] [Indexed: 11/26/2022]
Abstract
Laccases have high biotechnological potential in industries since they catalyze the oxidation of many chemical compounds. The production of laccases by fungi has been extensively studied due to their secretion of enzymes and rapid growth using cheap substrates. Trichoderma; the versatile fungal genus includes species of great biotechnological value and considered as a magnificent industrial cell factory of enzymes. In this study, 10 Trichoderma species were screened for laccase enzyme production by submerged cultivation. The studied species were identified by internal transcribed spacer (ITS) gene sequences. Guaiacol (0.04%) as an enzyme substrate in plate medium was used for the selection of maximum laccase-enriched Trichoderma species by formation of visual color halo intensity. This activity was evaluated by liquid submersion (flask medium) also. The absorbance of laccase contained broth was measured by a spectrophotometer (450 nm). The highest laccase production was obtained by T. atroviride (2.62 U/mL). Trichoderma cremeum and T. longipile showed medium laccase potency, while T. beinartii exhibited weak laccase secretion ability. Laccase from T. atroviride was purified by SDS-PAGE and the molecular weight was determined (57 kDa). The laccase was confirmed by their respective amino acid sequences, and the phylogenetic tree was constructed for further analysis.
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Affiliation(s)
- Aisha Umar
- University of the Punjab, Lahore, Pakistan.
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Subba A, Tomar S, Pareek A, Singla-Pareek SL. The chloride channels: Silently serving the plants. PHYSIOLOGIA PLANTARUM 2021; 171:688-702. [PMID: 33034380 DOI: 10.1111/ppl.13240] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 10/02/2020] [Accepted: 10/05/2020] [Indexed: 05/12/2023]
Abstract
Chloride channels (CLCs), member of anion transporting proteins, are present ubiquitously in all life forms. Diverging from its name, the CLC family includes both channel and exchanger (proton-coupled) proteins; nevertheless, they share conserved structural organization. They are engaged in diverse indispensable functions such as acid and fluoride tolerance in prokaryotes to muscle stabilization, transepithelial transport, and neuronal development in mammals. Mutations in genes encoding CLCs lead to several physiological disorders in different organisms, including severe diseases in humans. Even in plants, loss of CLC protein function severely impairs various cellular processes critical for normal growth and development. These proteins sequester Cl- into the vacuole, thus, making them an attractive target for improving salinity tolerance in plants caused by high abundance of salts, primarily NaCl. Besides, some CLCs are involved in NO3 - transport and storage function in plants, thus, influencing their nitrogen use efficiency. However, despite their high significance, not many studies have been carried out in plants. Here, we have attempted to concisely highlight the basic structure of CLC proteins and critical residues essential for their function and classification. We also present the diverse functions of CLCs in plants from their first cloning back in 1996 to the knowledge acquired as of now. We stress the need for carrying out more in-depth studies on CLCs in plants, for they may have future applications towards crop improvement.
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Affiliation(s)
- Ashish Subba
- Plant Stress Biology, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Surabhi Tomar
- Plant Stress Biology, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Ashwani Pareek
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Sneh L Singla-Pareek
- Plant Stress Biology, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
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Lu Z, Deng J, Wang H, Zhao X, Luo Z, Yu C, Zhang Y. Multifunctional role of a fungal pathogen-secreted laccase 2 in evasion of insect immune defense. Environ Microbiol 2021; 23:1256-1274. [PMID: 33393158 DOI: 10.1111/1462-2920.15378] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/25/2020] [Accepted: 12/26/2020] [Indexed: 11/29/2022]
Abstract
Laccases are widely present in bacteria, fungi, plants and invertebrates and involved in a variety of physiological functions. Here, we report that Beauveria bassiana, an economic important entomopathogenic fungus, secretes a laccase 2 (BbLac2) during infection that detoxifies insect immune response-generated reactive oxygen species (ROS) and interferes with host immune phenoloxidase (PO) activation. BbLac2 is expressed in fungal cells during proliferation in the insect haemocoel and can be found to distribute on the surface of haemolymph-derived in vivo fungal hyphal bodies or be secreted. Targeted gene-knockout of BbLac2 increased fungal sensitivity to oxidative stress, decreased virulence to insect, and increased host PO activity. Strains overexpressing BbLac2 showed increased virulence, with reduced host PO activity and lowered ROS levels in infected insects. In vitro assays revealed that BbLac2 could eliminate ROS and oxidize PO substrates (phenols), verifying the enzymatic functioning of the protein in detoxification of cytotoxic ROS and interference with the PO cascade. Moreover, BbLac2 acted as a cell surface protein that masked pathogen associated molecular patterns (PAMPs), enabling the pathogen to evade immune recognition. Our data suggest a multifunctional role for fungal pathogen-secreted laccase 2 in evasion of insect immune defenses.
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Affiliation(s)
- Zhuoyue Lu
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Southwest University, Chongqing, 400715, P. R. China
| | - Juan Deng
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Southwest University, Chongqing, 400715, P. R. China
| | - Huifang Wang
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Southwest University, Chongqing, 400715, P. R. China
| | - Xin Zhao
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Southwest University, Chongqing, 400715, P. R. China
| | - Zhibing Luo
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Southwest University, Chongqing, 400715, P. R. China
| | - Chenxi Yu
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Southwest University, Chongqing, 400715, P. R. China
| | - Yongjun Zhang
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Southwest University, Chongqing, 400715, P. R. China
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5
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Jha UC, Bohra A, Pandey S, Parida SK. Breeding, Genetics, and Genomics Approaches for Improving Fusarium Wilt Resistance in Major Grain Legumes. Front Genet 2020; 11:1001. [PMID: 33193586 PMCID: PMC7644945 DOI: 10.3389/fgene.2020.01001] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/06/2020] [Indexed: 12/29/2022] Open
Abstract
Fusarium wilt (FW) disease is the key constraint to grain legume production worldwide. The projected climate change is likely to exacerbate the current scenario. Of the various plant protection measures, genetic improvement of the disease resistance of crop cultivars remains the most economic, straightforward and environmental-friendly option to mitigate the risk. We begin with a brief recap of the classical genetic efforts that provided first insights into the genetic determinants controlling plant response to different races of FW pathogen in grain legumes. Subsequent technological breakthroughs like sequencing technologies have enhanced our understanding of the genetic basis of both plant resistance and pathogenicity. We present noteworthy examples of targeted improvement of plant resistance using genomics-assisted approaches. In parallel, modern functional genomic tools like RNA-seq are playing a greater role in illuminating the various aspects of plant-pathogen interaction. Further, proteomics and metabolomics have also been leveraged in recent years to reveal molecular players and various signaling pathways and complex networks participating in host-pathogen interaction. Finally, we present a perspective on the challenges and limitations of high-throughput phenotyping and emerging breeding approaches to expeditiously develop FW-resistant cultivars under the changing climate.
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Affiliation(s)
- Uday Chand Jha
- ICAR-Indian Institute of Pulses Research, Uttar Pradesh, India
| | - Abhishek Bohra
- ICAR-Indian Institute of Pulses Research, Uttar Pradesh, India
| | - Shailesh Pandey
- Forest Protection Division, Forest Research Institute, Dehradun, India
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Husaini AM, Sakina A, Cambay SR. Host-Pathogen Interaction in Fusarium oxysporum Infections: Where Do We Stand? MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2018; 31:889-898. [PMID: 29547356 DOI: 10.1094/mpmi-12-17-0302-cr] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Fusarium oxysporum, a ubiquitous soilborne pathogen, causes devastating vascular wilt in more than 100 plant species and ranks 5th among the top 10 fungal plant pathogens. It has emerged as a human pathogen, too, causing infections in immune-compromised patients. Therefore, it is important to gain insight into the molecular processes involved in the pathogenesis of this transkingdom pathogen. A complex network comprising interconnected and overlapping signal pathways-mitogen-activated protein kinase signaling pathways, Ras proteins, G-protein signaling components and their downstream pathways, components of the velvet (LaeA/VeA/VelB) complex, and cAMP pathways-is involved in perceiving the host. This network regulates the expression of various pathogenicity genes. However, plants have evolved an elaborate protection system to combat this attack. They, too, possess intricate mechanisms at the molecular level which, once triggered by pathogen attack, transduce signals to activate defense response. This review focuses on understanding and presenting a wholistic picture of the molecular mechanisms of F. oxysporum-host interactions in plant immunity.
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Affiliation(s)
- Amjad M Husaini
- 1 Genome Engineering Lab, Division of Plant Biotechnology, SKUAST-K, Shalimar, Jammu & Kashmir-190025, India
- 2 The Plant Chemetics Laboratory, Department of Plant Sciences, OX1 3RB South Parks Road, University of Oxford, U.K.; and
| | - Aafreen Sakina
- 1 Genome Engineering Lab, Division of Plant Biotechnology, SKUAST-K, Shalimar, Jammu & Kashmir-190025, India
| | - Souliha R Cambay
- 1 Genome Engineering Lab, Division of Plant Biotechnology, SKUAST-K, Shalimar, Jammu & Kashmir-190025, India
- 3 Division of Genetics, Indian Agricultural Research Institute, Pusa, New Delhi-110012, India
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7
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Hernández-Monjaraz WS, Caudillo-Pérez C, Salazar-Sánchez PU, Macías-Sánchez KL. Influence of iron and copper on the activity of laccases in Fusarium oxysporum f. sp. lycopersici. Braz J Microbiol 2018; 49 Suppl 1:269-275. [PMID: 30145263 PMCID: PMC6328805 DOI: 10.1016/j.bjm.2018.06.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Revised: 06/04/2018] [Accepted: 06/22/2018] [Indexed: 12/20/2022] Open
Abstract
Fusarium oxysporum f. sp. lycopersici is a phytopathogenic fungus that causes vascular wilt in tomato plants. In this work we analyze the influence of metal salts such as iron and copper sulphate, as well as that of bathophenanthrolinedisulfonic acid (iron chelator) and bathocuproinedisulfonic acid (copper chelator) on the activity of laccases in the intra (IF) and extracellular fractions (EF) of the wild-type and the non-pathogenic mutant strain (rho1::hyg) of F. oxysporum. The results show that laccase activity in the IF fraction of the wild and mutant strain increased with the addition of iron chelator (53.4 and 114.32%; respectively). With copper, it is observed that there is an inhibition of the activity with the addition of CuSO4 for the EF of the wild and mutant strain (reduction of 82 and 62.6%; respectively) and for the IF of the mutant strain (54.8%). With the copper chelator a less laccase activity in the IF of the mutant strain was observed (reduction of 53.9%). The results obtained suggest a different regulation of intracellular laccases in the mutant strain compared with the wild type in presence of CuSO4 and copper chelator which may be due to the mutation in the rho gene.
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Affiliation(s)
- Wendy Susana Hernández-Monjaraz
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Ingeniería campus Guanajuato, Silao de la Victoria, Guanajuato, Mexico
| | - César Caudillo-Pérez
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Ingeniería campus Guanajuato, Silao de la Victoria, Guanajuato, Mexico
| | - Pedro Ulises Salazar-Sánchez
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Ingeniería campus Guanajuato, Silao de la Victoria, Guanajuato, Mexico
| | - Karla Lizbeth Macías-Sánchez
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Ingeniería campus Guanajuato, Silao de la Victoria, Guanajuato, Mexico.
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8
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Khantwal CM, Abraham SJ, Han W, Jiang T, Chavan TS, Cheng RC, Elvington SM, Liu CW, Mathews II, Stein RA, Mchaourab HS, Tajkhorshid E, Maduke M. Revealing an outward-facing open conformational state in a CLC Cl(-)/H(+) exchange transporter. eLife 2016; 5. [PMID: 26799336 PMCID: PMC4769167 DOI: 10.7554/elife.11189] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 01/14/2016] [Indexed: 11/22/2022] Open
Abstract
CLC secondary active transporters exchange Cl- for H+. Crystal structures have suggested that the conformational change from occluded to outward-facing states is unusually simple, involving only the rotation of a conserved glutamate (Gluex) upon its protonation. Using 19F NMR, we show that as [H+] is increased to protonate Gluex and enrich the outward-facing state, a residue ~20 Å away from Gluex, near the subunit interface, moves from buried to solvent-exposed. Consistent with functional relevance of this motion, constriction via inter-subunit cross-linking reduces transport. Molecular dynamics simulations indicate that the cross-link dampens extracellular gate-opening motions. In support of this model, mutations that decrease steric contact between Helix N (part of the extracellular gate) and Helix P (at the subunit interface) remove the inhibitory effect of the cross-link. Together, these results demonstrate the formation of a previously uncharacterized 'outward-facing open' state, and highlight the relevance of global structural changes in CLC function. DOI:http://dx.doi.org/10.7554/eLife.11189.001 Cells have transporter proteins on their surface to carry molecules in and out of the cell. For example, the CLC family of transporters move two chloride ions in one direction at the same time as moving one hydrogen ion in the opposite direction. To be able to move these ions in opposite directions, transporters have to cycle through a series of shapes in which the ions can only access alternate sides of the membrane. First, the transporter adopts an 'outward-facing' shape when the ions first bind to the transporter, then it switches into the 'occluded' shape to move the ions through the membrane. Finally, the transporter takes on the 'inward-facing' shape to release the ions on the other side of the membrane. However, structural studies of CLCs suggest that the structures of these proteins do not change much while they are moving ions, which suggests that they might work in a different way. Khantwal, Abraham et al. have now used techniques called “nuclear magnetic resonance” and "double electron-electron resonance" to investigate how a CLC from a bacterium moves ions. The experiments suggest that when the transporter adopts the outward-facing shape, points on the protein known as Y419 and D417 shift their positions. Chemically linking two regions of the CLC prevented this movement and inhibited the transport of chloride ions across the membrane. Khantwal, Abraham et al. then used a computer simulation to model how the protein changes shape in more detail. This model predicts that two regions of the transporter undergo major rearrangements resulting in a gate-opening motion that widens a passage to allow the chloride ions to bind to the protein. Khantwal, Abraham et al.’s findings will prompt future studies to reveal the other shapes and how CLCs transition between them. DOI:http://dx.doi.org/10.7554/eLife.11189.002
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Affiliation(s)
- Chandra M Khantwal
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, United States
| | - Sherwin J Abraham
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, United States
| | - Wei Han
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, United States.,College of Medicine, University of Illinois at Urbana-Champaign, Urbana, United States.,Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, United States.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States
| | - Tao Jiang
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, United States.,College of Medicine, University of Illinois at Urbana-Champaign, Urbana, United States.,Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, United States.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States
| | - Tanmay S Chavan
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, United States
| | - Ricky C Cheng
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, United States
| | - Shelley M Elvington
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, United States
| | - Corey W Liu
- Stanford Magnetic Resonance Laboratory, Stanford University School of Medicine, Stanford, United States
| | - Irimpan I Mathews
- Stanford Synchrotron Radiation Lightsource, Stanford University, Menlo Park, United States
| | - Richard A Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, United States
| | - Hassane S Mchaourab
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, United States
| | - Emad Tajkhorshid
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, United States.,College of Medicine, University of Illinois at Urbana-Champaign, Urbana, United States.,Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, United States.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States
| | - Merritt Maduke
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, United States
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Nižňanský L, Kryštofová S, Vargovič P, Kaliňák M, Simkovič M, Varečka L. Glutamic acid decarboxylase gene disruption reveals signalling pathway(s) governing complex morphogenic and metabolic events in Trichoderma atroviride. Antonie van Leeuwenhoek 2013; 104:793-807. [PMID: 23912446 DOI: 10.1007/s10482-013-9989-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 07/25/2013] [Indexed: 11/29/2022]
Abstract
Glutamate decarboxylase (GAD) catalyses decarboxylation of glutamate to gamma-aminobutyrate (GABA) in a metabolic pathway connected to citrate cycle and known as GABA shunt. The gene (gad) was disrupted in Trichoderma atroviride CCM F-534 and viable mutants were characterized. Two of them were found to arise by homologous recombination and were devoid of both GAD activity and GABA. Mutants grew slower as compared to the wild type (F534). In the submerged culture, mutants developed less CO2 and consumed less O2 than the F534 without changing their respiratory quotients. Hyphae of mutants were more ramified than those of F534. Their ramification, in contrast to F534, was not increased by cyclosporin A, a drug causing hyphae ramification of several fungi and which is a calcineurin/cyclophilin inhibitor, or by FK506. Rapamycin, which is a cyclophilin but not calcineurin inhibitor, had a different effect on hyphae ramification in F534 and mutants. To examine the presence of GABA receptors in the fungus the effect of mammalian GABA-receptor modulators, such as bicuculline, gabapentin or carbamazepine on fungal morphology were investigated. Conidia of mutants germinated in a multipolar manner more frequently (up to 80 %) than those of F534. This trait was modified with cyclosporine A, FK506 and GABA receptor modulators in a different manner. Transport of chlorides, an intimate feature of GABA-regulated receptors/channels in animal cells, was measured in vegetative mycelia by means (36)Cl(-) uptake. It was significantly reduced in gad mutants. The results suggest that T. atroviride possesses a signalling pathway that involves GABA, putative GABA receptor(s), calcineurin, target of rapamycin and chloride transporter(s) to regulate physiological functions.
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Affiliation(s)
- Luboš Nižňanský
- Department of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37, Bratislava, Slovakia,
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Michielse CB, Reijnen L, Olivain C, Alabouvette C, Rep M. Degradation of aromatic compounds through the β-ketoadipate pathway is required for pathogenicity of the tomato wilt pathogen Fusarium oxysporum f. sp. lycopersici. MOLECULAR PLANT PATHOLOGY 2012; 13:1089-100. [PMID: 22827542 PMCID: PMC6638894 DOI: 10.1111/j.1364-3703.2012.00818.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Plant roots react to pathogen attack by the activation of general and systemic resistance, including the lignification of cell walls and increased release of phenolic compounds in root exudate. Some fungi have the capacity to degrade lignin using ligninolytic extracellular peroxidases and laccases. Aromatic lignin breakdown products are further catabolized via the β-ketoadipate pathway. In this study, we investigated the role of 3-carboxy-cis,cis-muconate lactonizing enzyme (CMLE), an enzyme of the β-ketoadipate pathway, in the pathogenicity of Fusarium oxysporum f. sp. lycopersici towards its host, tomato. As expected, the cmle deletion mutant cannot catabolize phenolic compounds known to be degraded via the β-ketoadipate pathway. In addition, the mutant is impaired in root invasion and is nonpathogenic, even though it shows normal superficial root colonization. We hypothesize that the β-ketoadipate pathway in plant-pathogenic, soil-borne fungi is necessary to degrade phenolic compounds in root exudate and/or inside roots in order to establish disease.
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Affiliation(s)
- Caroline B Michielse
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands.
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Expression of the laccase gene from a white rot fungus in Pichia pastoris can enhance the resistance of this yeast to H2O2-mediated oxidative stress by stimulating the glutathione-based antioxidative system. Appl Environ Microbiol 2012; 78:5845-54. [PMID: 22706050 DOI: 10.1128/aem.00218-12] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Laccase is a copper-containing polyphenol oxidase that has great potential in industrial and biotechnological applications. Previous research has suggested that fungal laccase may be involved in the defense against oxidative stress, but there is little direct evidence supporting this hypothesis, and the mechanism by which laccase protects cells from oxidative stress also remains unclear. Here, we report that the expression of the laccase gene from white rot fungus in Pichia pastoris can significantly enhance the resistance of yeast to H(2)O(2)-mediated oxidative stress. The expression of laccase in yeast was found to confer a strong ability to scavenge intracellular H(2)O(2) and to protect cells from lipid oxidative damage. The mechanism by which laccase gene expression increases resistance to oxidative stress was then investigated further. We found that laccase gene expression in Pichia pastoris could increase the level of glutathione-based antioxidative activity, including the intracellular glutathione levels and the enzymatic activity of glutathione peroxidase, glutathione reductase, and γ-glutamylcysteine synthetase. The transcription of the laccase gene in Pichia pastoris was found to be enhanced by the oxidative stress caused by exogenous H(2)O(2). The stimulation of laccase gene expression in response to exogenous H(2)O(2) stress further contributed to the transcriptional induction of the genes involved in the glutathione-dependent antioxidative system, including PpYAP1, PpGPX1, PpPMP20, PpGLR1, and PpGSH1. Taken together, these results suggest that the expression of the laccase gene in Pichia pastoris can enhance the resistance of yeast to H(2)O(2)-mediated oxidative stress by stimulating the glutathione-based antioxidative system to protect the cell from oxidative damage.
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Abstract
TAXONOMY Kingdom Fungi; Phylum Ascomycota; Class Sordariomycetes; Order Hypocreales; Family Nectriaceae; genus Fusarium. HOST RANGE Very broad at the species level. More than 120 different formae speciales have been identified based on specificity to host species belonging to a wide range of plant families. DISEASE SYMPTOMS Initial symptoms of vascular wilt include vein clearing and leaf epinasty, followed by stunting, yellowing of the lower leaves, progressive wilting, defoliation and, finally, death of the plant. On fungal colonization, the vascular tissue turns brown, which is clearly visible in cross-sections of the stem. Some formae speciales are not primarily vascular pathogens, but cause foot and root rot or bulb rot. ECONOMIC IMPORTANCE Can cause severe losses in many vegetables and flowers, field crops, such as cotton, and plantation crops, such as banana, date palm and oil palm. CONTROL Use of resistant varieties is the only practical measure for controlling the disease in the field. In glasshouses, soil sterilization can be performed. USEFUL WEBSITES http://www.broad.mit.edu/annotation/genome/fusarium_group/MultiHome.html; http://www.fgsc.net/Fusarium/fushome.htm; http://www.phi-base.org/query.php
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Affiliation(s)
- Caroline B Michielse
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
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Michielse CB, van Wijk R, Reijnen L, Cornelissen BJC, Rep M. Insight into the molecular requirements for pathogenicity of Fusarium oxysporum f. sp. lycopersici through large-scale insertional mutagenesis. Genome Biol 2009; 10:R4. [PMID: 19134172 PMCID: PMC2687792 DOI: 10.1186/gb-2009-10-1-r4] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 12/22/2008] [Accepted: 01/09/2009] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Fusarium oxysporum f. sp. lycopersici is the causal agent of vascular wilt disease in tomato. In order to gain more insight into the molecular processes in F. oxysporum necessary for pathogenesis and to uncover the genes involved, we used Agrobacterium-mediated insertional mutagenesis to generate 10,290 transformants and screened the transformants for loss or reduction of pathogenicity. RESULTS This led to the identification of 106 pathogenicity mutants. Southern analysis revealed that the average T-DNA insertion is 1.4 and that 66% of the mutants carry a single T-DNA. Using TAIL-PCR, chromosomal T-DNA flanking regions were isolated and 111 potential pathogenicity genes were identified. CONCLUSIONS Functional categorization of the potential pathogenicity genes indicates that certain cellular processes, such as amino acid and lipid metabolism, cell wall remodeling, protein translocation and protein degradation, seem to be important for full pathogenicity of F. oxysporum. Several known pathogenicity genes were identified, such as those encoding chitin synthase V, developmental regulator FlbA and phosphomannose isomerase. In addition, complementation and gene knock-out experiments confirmed that a glycosylphosphatidylinositol-anchored protein, thought to be involved in cell wall integrity, a transcriptional regulator, a protein with unknown function and peroxisome biogenesis are required for full pathogenicity of F. oxysporum.
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Affiliation(s)
- Caroline B Michielse
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands
| | - Ringo van Wijk
- Current address: Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands
| | - Linda Reijnen
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands
| | - Ben JC Cornelissen
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands
| | - Martijn Rep
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands
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