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De Bruyne L, Van Poucke C, Di Mavungu DJ, Zainudin NAIM, Vanhaecke L, De Vleesschauwer D, Turgeon BG, De Saeger S, Höfte M. Comparative chemical screening and genetic analysis reveal tentoxin as a new virulence factor in Cochliobolus miyabeanus, the causal agent of brown spot disease on rice. MOLECULAR PLANT PATHOLOGY 2016; 17:805-17. [PMID: 26456797 PMCID: PMC6638388 DOI: 10.1111/mpp.12329] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Brown spot disease, caused by Cochliobolus miyabeanus, is currently considered to be one of the most important yield reducers of rice (Oryza sativa L.). Despite its agricultural importance, little is known about the virulence mechanisms deployed by the fungus. Therefore, we set out to identify novel virulence factors with a role in disease development. This article reports, for the first time, the production of tentoxin by C. miyabeanus as a virulence factor during brown spot disease and the identification of the non-ribosomal protein synthetase (NRPS) CmNps3, responsible for tentoxin biosynthesis. We compared the chemical compounds produced by C. miyabeanus strains differing in virulence ability using ultra-high-performance liquid chromatography (UHPLC) coupled to high-resolution Orbitrap mass spectrometry (HRMS). The production of tentoxin by a highly virulent strain was revealed by principal component analysis of the detected ions and confirmed by UHPLC coupled to tandem-quadrupole mass spectrometry (MS/MS). The corresponding NRPS was identified by in silico genome analysis and confirmed by gene deletion. Infection tests with wild-type and Cmnps3 mutants showed that tentoxin acts as a virulence factor and is correlated with chlorosis development during the second phase of infection. Although rice has previously been classified as a tentoxin-insensitive plant species, our data demonstrate that tentoxin production by C. miyabeanus affects symptom development.
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Affiliation(s)
- Lieselotte De Bruyne
- Department of Crop Protection, Laboratory of Phytopathology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, BE-9000, Ghent, Belgium
| | - Christof Van Poucke
- Department of Bio-analysis, Laboratory of Food Analysis, Faculty of Pharmaceutical Sciences, Ghent University, BE-9000, Ghent, Belgium
| | - Diana Jose Di Mavungu
- Department of Bio-analysis, Laboratory of Food Analysis, Faculty of Pharmaceutical Sciences, Ghent University, BE-9000, Ghent, Belgium
| | - Nur Ain Izzati Mohd Zainudin
- Section of Plant Pathology & Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, 14850, Ithaca, NY, USA
- Department of Biology, Faculty of Science, University Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Lynn Vanhaecke
- Department of Veterinary Public Health and Food Safety, Laboratory of Chemical Analysis, Faculty of Veterinary Medicine, Ghent University, BE-9000, Ghent, Belgium
| | - David De Vleesschauwer
- Department of Crop Protection, Laboratory of Phytopathology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, BE-9000, Ghent, Belgium
| | - B Gillian Turgeon
- Section of Plant Pathology & Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, 14850, Ithaca, NY, USA
| | - Sarah De Saeger
- Department of Bio-analysis, Laboratory of Food Analysis, Faculty of Pharmaceutical Sciences, Ghent University, BE-9000, Ghent, Belgium
| | - Monica Höfte
- Department of Crop Protection, Laboratory of Phytopathology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, BE-9000, Ghent, Belgium
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Shi LX, Theg SM. Energetic cost of protein import across the envelope membranes of chloroplasts. Proc Natl Acad Sci U S A 2013; 110:930-5. [PMID: 23277572 PMCID: PMC3549074 DOI: 10.1073/pnas.1115886110] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Chloroplasts are the organelles of green plants in which light energy is transduced into chemical energy, forming ATP and reduced carbon compounds upon which all life depends. The expenditure of this energy is one of the central issues of cellular metabolism. Chloroplasts contain ~3,000 proteins, among which less than 100 are typically encoded in the plastid genome. The rest are encoded in the nuclear genome, synthesized in the cytosol, and posttranslationally imported into the organelle in an energy-dependent process. We report here a measurement of the amount of ATP hydrolyzed to import a protein across the chloroplast envelope membranes--only the second complete accounting of the cost in Gibbs free energy of protein transport to be undertaken. Using two different precursors prepared by three distinct techniques, we show that the import of a precursor protein into chloroplasts is accompanied by the hydrolysis of ~650 ATP molecules. This translates to a ΔG(protein) (transport) of some 27,300 kJ/mol protein imported. We estimate that protein import across the plastid envelope membranes consumes ~0.6% of the total light-saturated energy output of the organelle.
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Affiliation(s)
- Lan-Xin Shi
- Department of Plant Biology, University of California, Davis, CA 95616
| | - Steven M. Theg
- Department of Plant Biology, University of California, Davis, CA 95616
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Uner NE, Nishikawa Y, Okuno D, Nakano M, Yokoyama K, Noji H. Single-molecule analysis of inhibitory pausing states of V1-ATPase. J Biol Chem 2012; 287:28327-35. [PMID: 22736762 DOI: 10.1074/jbc.m112.381194] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
V(1)-ATPase, the hydrophilic V-ATPase domain, is a rotary motor fueled by ATP hydrolysis. Here, we found that Thermus thermophilus V(1)-ATPase shows two types of inhibitory pauses interrupting continuous rotation: a short pause (SP, 4.2 s) that occurred frequently during rotation, and a long inhibitory pause (LP, >30 min) that terminated all active rotations. Both pauses occurred at the same angle for ATP binding and hydrolysis. Kinetic analysis revealed that the time constants of inactivation into and activation from the SP were too short to represent biochemically predicted ADP inhibition, suggesting that SP is a newly identified inhibitory state of V(1)-ATPase. The time constant of inactivation into LP was 17 min, consistent with one of the two time constants governing the inactivation process observed in bulk ATPase assay. When forcibly rotated in the forward direction, V(1) in LP resumed active rotation. Solution ADP suppressed the probability of mechanical activation, suggesting that mechanical rotation enhanced inhibitory ADP release. These features were highly consistent with mechanical activation of ADP-inhibited F(1), suggesting that LP represents the ADP-inhibited state of V(1)-ATPase. Mechanical activation largely depended on the direction and angular displacement of forced rotation, implying that V(1)-ATPase rotation modulates the off rate of ADP.
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Affiliation(s)
- Naciye Esma Uner
- Department of Biotechnology, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
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Sunamura EI, Konno H, Imashimizu-Kobayashi M, Sugano Y, Hisabori T. Physiological impact of intrinsic ADP inhibition of cyanobacterial FoF1 conferred by the inherent sequence inserted into the gammasubunit. PLANT & CELL PHYSIOLOGY 2010; 51:855-65. [PMID: 20421199 DOI: 10.1093/pcp/pcq061] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The F(o)F(1)-ATPase, which synthesizes ATP with a rotary motion, is highly regulated in vivo in order to function efficiently, although there remains a limited understanding of the physiological significance of this regulation. Compared with its bacterial and mitochondrial counterparts, the gamma subunit of cyanobacterial F(1), which makes up the central shaft of the motor enzyme, contains an additional inserted region. Although deletion of this region results in the acceleration of the rate of ATP hydrolysis, the functional significance of the region has not yet been determined. By analysis of rotation, we successfully determined that this region confers the ability to shift frequently into an ADP inhibition state; this is a highly conserved regulatory mechanism which prevents ATP synthase from carrying out the reverse reaction. We believe that the physiological significance of this increased likelihood of shifting into the ADP inhibition state allows the intracellular ATP levels to be maintained, which is especially critical for photosynthetic organisms.
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Affiliation(s)
- Ei-Ichiro Sunamura
- Chemical Resources Laboratory, Tokyo Institute of Technology, Nagatsuta 4259-R1-8, Midori-Ku, Yokohama 226-8503, Japan
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Ristic Z, Vitali M, Duci A, Goetze C, Kemnitz K, Zuschratter W, Lill H, Bald D. Two-stimuli manipulation of a biological motor. J Nanobiotechnology 2009; 7:3. [PMID: 19445679 PMCID: PMC2693425 DOI: 10.1186/1477-3155-7-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 05/15/2009] [Indexed: 11/10/2022] Open
Abstract
F1-ATPase is an enzyme acting as a rotary nano-motor. During catalysis subunits of this enzyme complex rotate relative to other parts of the enzyme. Here we demonstrate that the combination of two input stimuli causes stop of motor rotation. Application of either individual stimulus did not significantly influence motor motion. These findings may contribute to the development of logic gates using single biological motor molecules.
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Affiliation(s)
- Zorica Ristic
- Department of Molecular Cell Biology, VU University Amsterdam, Amsterdam, the Netherlands.
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Meiss E, Konno H, Groth G, Hisabori T. Molecular processes of inhibition and stimulation of ATP synthase caused by the phytotoxin tentoxin. J Biol Chem 2008; 283:24594-9. [PMID: 18579520 DOI: 10.1074/jbc.m802574200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
F1-ATPase is the smallest mechanical motor known. Tentoxin, a cyclic peptide produced by phytopathogenic fungi, inactivates the F1 motor in sensitive plants at nanomolar to micromolar concentrations, whereas higher concentrations surpass the natural activity of the enzyme. Single molecule studies now have clarified the molecular steps involved in both processes. Inactivation delays the dwell time of a single step in the complete 360 degrees turn and results in an asymmetric rotation of the central rotor subunit. In contrast, rotation in the stimulated F1 particle is smooth and accompanied by strongly reduced ADP inhibition. Our study provides for the first time the direct observation of a noncompetitively inhibited state of the enzyme and directly visualizes the regulation of the molecular motor by an external natural compound. In addition, the ADP release step during catalysis was revealed by analysis of the single molecule rotation behavior. Hence, tentoxin is a sophisticated molecular tool to mark and control certain catalytic steps within the reaction pathway of the molecular F1 motor.
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Affiliation(s)
- Erik Meiss
- Chemical Resources Laboratory, Tokyo Institute of Technology, Nagatsuta 4259-R1-8, Yokohama 226-8503, Japan
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Thines E, Aguirre J, Foster AJ, Deising HB. Genetics of phytopathology: Secondary metabolites as virulence determinants of fungal plant pathogens. ACTA ACUST UNITED AC 2006. [DOI: 10.1007/3-540-27998-9_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
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