The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform
John D. Williamson - One of the best experts on this subject based on the ideXlab platform.
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Mannitol in plants fungi and plant fungal interactions
Trends in Plant Science, 2016Co-Authors: Takshay K. Patel, John D. WilliamsonAbstract:Although the presence of Mannitol in organisms as diverse as plants and fungi clearly suggests that this compound has important roles, our understanding of fungal Mannitol metabolism and its interaction with Mannitol metabolism in plants is far from complete. Despite recent inroads into understanding the importance of Mannitol and its metabolic roles in salt, osmotic, and oxidative stress tolerance in plants and fungi, our current understanding of exactly how Mannitol protects against reactive oxygen is also still incomplete. In this opinion, we propose a new model of the interface between Mannitol metabolism in plants and fungi and how it impacts plant–pathogen interactions.
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Mannitol in Plants, Fungi, and Plant–Fungal Interactions
Trends in Plant Science, 2016Co-Authors: Takshay K. Patel, John D. WilliamsonAbstract:Although the presence of Mannitol in organisms as diverse as plants and fungi clearly suggests that this compound has important roles, our understanding of fungal Mannitol metabolism and its interaction with Mannitol metabolism in plants is far from complete. Despite recent inroads into understanding the importance of Mannitol and its metabolic roles in salt, osmotic, and oxidative stress tolerance in plants and fungi, our current understanding of exactly how Mannitol protects against reactive oxygen is also still incomplete. In this opinion, we propose a new model of the interface between Mannitol metabolism in plants and fungi and how it impacts plant–pathogen interactions.
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Overexpression of Mannitol dehydrogenase in zonal geranium confers increased resistance to the Mannitol secreting fungal pathogen Botrytis cinerea
Plant Cell Tissue and Organ Culture (PCTOC), 2013Co-Authors: John D. Williamson, Aparna Desai, Sergei F. Krasnyanski, Wei-wen Guo, Thanh-tuyen Nguyen, Heather A. Olson, John M Dole, Fei Ding, George C. AllenAbstract:The sugar alcohol Mannitol is a carbohydrate with well-documented roles in both metabolism and osmoprotection in plants and fungi. In addition, however, Mannitol is an antioxidant, and current research suggests that pathogenic fungi can secrete Mannitol into the plant’s extracellular spaces during infection to suppress reactive oxygen-mediated host defenses. In response to pathogen attack, plants have been shown to secrete the normally symplastic enzyme, Mannitol dehydrogenase (MTD). Given that MTD converts Mannitol to the sugar mannose, extracellular MTD may be an important defense against Mannitol-secreting fungal pathogens. Previous work demonstrated that overexpression of MTD in tobacco did, in fact, provide increased resistance to the Mannitol-secreting fungal pathogen Alternaria alternata. In the present work we demonstrate that the fungal pathogen Botrytis cinerea also can secrete Mannitol, and that overexpression of MTD in zonal geranium (Pelargonium × hortorum) in turn provides increased resistance to B. cinerea. These results are not only an important validation of previous work, but support the idea that MTD-overexpression might be used to engineer a broad variety of plants for resistance to Mannitol-secreting fungal pathogens like B. cinerea for which specific resistance is lacking.
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Constitutive expression of a celery Mannitol dehydrogenase in tobacco enhances resistance to the Mannitol‐secreting fungal pathogen Alternaria alternata
Plant Journal, 2002Co-Authors: Dianne B. Jennings, Margaret E. Daub, D. Mason Pharr, John D. WilliamsonAbstract:Summary Our previous observation that host plant extracts induce production and secretion of Mannitol in the tobacco pathogen Alternaria alternata suggested that, like their animal counterparts, plant pathogenic fungi might produce the reactive oxygen quencher Mannitol as a means of suppressing reactive oxygen- mediated plant defenses. The concurrent discovery that pathogen attack induced Mannitol dehydrogenase (MTD) expression in the non-Mannitol-containing host tobacco suggested that plants, unlike animals, might be able to counter this fungal suppressive mechanism by catabolizing Mannitol of fungal origin. To test this hypothesis, transgenic tobacco plants constitutively expressing a celery Mtd cDNA were pro- duced and evaluated for potential changes in resistance to both Mannitol- and non-Mannitol-secreting pathogens. Constitutive expression of the MTD transgene was found to confer significantly enhanced resistance to A. alternata, but not to the non-Mannitol-secreting fungal pathogen Cercospora nicotianae. These results are consistent with the hypothesis that MTD plays a role in resistance to Mannitol-secreting fungal plant pathogens.
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Roles for Mannitol and Mannitol dehydrogenase in active oxygen-mediated plant defense
Proceedings of the National Academy of Sciences of the United States of America, 1998Co-Authors: Dianne B. Jennings, D. Mason Pharr, Marilyn Ehrenshaft, John D. WilliamsonAbstract:Reactive oxygen species (ROS) are both signal molecules and direct participants in plant defense against pathogens. Many fungi synthesize Mannitol, a potent quencher of ROS, and there is growing evidence that at least some phytopathogenic fungi use Mannitol to suppress ROS-mediated plant defenses. Here we show induction of Mannitol production and secretion in the phytopathogenic fungus Alternaria alternata in the presence of host-plant extracts. Conversely, we show that the catabolic enzyme Mannitol dehydrogenase is induced in a non-Mannitol-producing plant in response to both fungal infection and specific inducers of plant defense responses. This provides a mechanism whereby the plant can counteract fungal suppression of ROS-mediated defenses by catabolizing Mannitol of fungal origin.
Thierry Dulermo - One of the best experts on this subject based on the ideXlab platform.
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novel insights into Mannitol metabolism in the fungal plant pathogen botrytis cinerea
Biochemical Journal, 2010Co-Authors: Thierry Dulermo, Christine Rascle, Richard Bligny, Elisabeth Gout, Genevieve Billongrand, Pascale CottonAbstract:In order to redefine the Mannitol pathway in the necrotrophic plant pathogen Botrytis cinerea, we used a targeted deletion strategy of genes encoding two proteins of Mannitol metabolism, BcMTDH (B. cinerea Mannitol dehydrogenase) and BcMPD (B. cinerea Mannitol-1-phosphate dehydrogenase). Mobilization of Mannitol and quantification of Bcmpd and Bcmtdh gene transcripts during development and osmotic stress confirmed a role for Mannitol as a temporary and disposable carbon storage compound. In order to study metabolic fluxes, we followed conversion of labelled hexoses in wild-type and ΔBcmpd and ΔBcmtdh mutant strains by in vivo NMR spectroscopy. Our results revealed that glucose and fructose were metabolized via the BcMPD and BcMTDH pathways respectively. The existence of a novel Mannitol phosphorylation pathway was also suggested by the NMR investigations. This last finding definitively challenged the existence of the originally postulated Mannitol cycle in favour of two simultaneously expressed pathways. Finally, physiological and biochemical studies conducted on double deletion mutants (ΔBcmpdΔBcmtdh) showed that Mannitol was still produced despite a complete alteration of both Mannitol biosynthesis pathways. This strongly suggests that one or several additional undescribed pathways could participate in Mannitol metabolism in B. cinerea.
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Novel insights into Mannitol metabolism in the fungal plant pathogen Botrytis cinerea
Biochemical Journal, 2010Co-Authors: Thierry Dulermo, Christine Rascle, Geneviève Billon-grand, Richard Bligny, Elisabeth Gout, Pascale CottonAbstract:In order to redefine the Mannitol pathway in the necrotrophic plant pathogen Botrytis cinerea, we used a targeted deletion strategy of genes encoding two proteins of Mannitol metabolism, a Mannitol dehydrogenase (BcMTDH), and a Mannitol-1-phosphate dehydrogenase (BcMPD). Mobilization of Mannitol and quantification of Bcmpd and Bcmtdh gene transcripts during development and osmotic stress confirmed a role for Mannitol as temporary and disposable carbon storage compound. In order to study metabolic fluxes, we followed conversion of labelled hexoses by wild type and Bcmpd and Bcmtdh mutant strains by in vivo NMR spectroscopy. Our data revealed that glucose and fructose were metabolized via the BcMPD and BcMTDH pathways, respectively. Existence of a novel Mannitol phosphorylation pathway was suggested by NMR investigations for the first time. This last finding definitively challenged the existence of the originally postulated Mannitol cycle in favor of two simultaneously expressed pathways. Finally, physiological and biochemical studies conducted on double deletion mutants (Bcmpd/Bcmtdh) showed that Mannitol was still produced despite a complete alteration of both Mannitol biosynthesis pathways. This strongly suggests that one or several additional undescribed pathways could participate to Mannitol metabolism in B. cinerea.
Pascale Cotton - One of the best experts on this subject based on the ideXlab platform.
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novel insights into Mannitol metabolism in the fungal plant pathogen botrytis cinerea
Biochemical Journal, 2010Co-Authors: Thierry Dulermo, Christine Rascle, Richard Bligny, Elisabeth Gout, Genevieve Billongrand, Pascale CottonAbstract:In order to redefine the Mannitol pathway in the necrotrophic plant pathogen Botrytis cinerea, we used a targeted deletion strategy of genes encoding two proteins of Mannitol metabolism, BcMTDH (B. cinerea Mannitol dehydrogenase) and BcMPD (B. cinerea Mannitol-1-phosphate dehydrogenase). Mobilization of Mannitol and quantification of Bcmpd and Bcmtdh gene transcripts during development and osmotic stress confirmed a role for Mannitol as a temporary and disposable carbon storage compound. In order to study metabolic fluxes, we followed conversion of labelled hexoses in wild-type and ΔBcmpd and ΔBcmtdh mutant strains by in vivo NMR spectroscopy. Our results revealed that glucose and fructose were metabolized via the BcMPD and BcMTDH pathways respectively. The existence of a novel Mannitol phosphorylation pathway was also suggested by the NMR investigations. This last finding definitively challenged the existence of the originally postulated Mannitol cycle in favour of two simultaneously expressed pathways. Finally, physiological and biochemical studies conducted on double deletion mutants (ΔBcmpdΔBcmtdh) showed that Mannitol was still produced despite a complete alteration of both Mannitol biosynthesis pathways. This strongly suggests that one or several additional undescribed pathways could participate in Mannitol metabolism in B. cinerea.
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Novel insights into Mannitol metabolism in the fungal plant pathogen Botrytis cinerea
Biochemical Journal, 2010Co-Authors: Thierry Dulermo, Christine Rascle, Geneviève Billon-grand, Richard Bligny, Elisabeth Gout, Pascale CottonAbstract:In order to redefine the Mannitol pathway in the necrotrophic plant pathogen Botrytis cinerea, we used a targeted deletion strategy of genes encoding two proteins of Mannitol metabolism, a Mannitol dehydrogenase (BcMTDH), and a Mannitol-1-phosphate dehydrogenase (BcMPD). Mobilization of Mannitol and quantification of Bcmpd and Bcmtdh gene transcripts during development and osmotic stress confirmed a role for Mannitol as temporary and disposable carbon storage compound. In order to study metabolic fluxes, we followed conversion of labelled hexoses by wild type and Bcmpd and Bcmtdh mutant strains by in vivo NMR spectroscopy. Our data revealed that glucose and fructose were metabolized via the BcMPD and BcMTDH pathways, respectively. Existence of a novel Mannitol phosphorylation pathway was suggested by NMR investigations for the first time. This last finding definitively challenged the existence of the originally postulated Mannitol cycle in favor of two simultaneously expressed pathways. Finally, physiological and biochemical studies conducted on double deletion mutants (Bcmpd/Bcmtdh) showed that Mannitol was still produced despite a complete alteration of both Mannitol biosynthesis pathways. This strongly suggests that one or several additional undescribed pathways could participate to Mannitol metabolism in B. cinerea.
George C. Allen - One of the best experts on this subject based on the ideXlab platform.
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Overexpression of Mannitol dehydrogenase in zonal geranium confers increased resistance to the Mannitol secreting fungal pathogen Botrytis cinerea
Plant Cell Tissue and Organ Culture (PCTOC), 2013Co-Authors: John D. Williamson, Aparna Desai, Sergei F. Krasnyanski, Wei-wen Guo, Thanh-tuyen Nguyen, Heather A. Olson, John M Dole, Fei Ding, George C. AllenAbstract:The sugar alcohol Mannitol is a carbohydrate with well-documented roles in both metabolism and osmoprotection in plants and fungi. In addition, however, Mannitol is an antioxidant, and current research suggests that pathogenic fungi can secrete Mannitol into the plant’s extracellular spaces during infection to suppress reactive oxygen-mediated host defenses. In response to pathogen attack, plants have been shown to secrete the normally symplastic enzyme, Mannitol dehydrogenase (MTD). Given that MTD converts Mannitol to the sugar mannose, extracellular MTD may be an important defense against Mannitol-secreting fungal pathogens. Previous work demonstrated that overexpression of MTD in tobacco did, in fact, provide increased resistance to the Mannitol-secreting fungal pathogen Alternaria alternata. In the present work we demonstrate that the fungal pathogen Botrytis cinerea also can secrete Mannitol, and that overexpression of MTD in zonal geranium (Pelargonium × hortorum) in turn provides increased resistance to B. cinerea. These results are not only an important validation of previous work, but support the idea that MTD-overexpression might be used to engineer a broad variety of plants for resistance to Mannitol-secreting fungal pathogens like B. cinerea for which specific resistance is lacking.
Elisabeth Gout - One of the best experts on this subject based on the ideXlab platform.
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novel insights into Mannitol metabolism in the fungal plant pathogen botrytis cinerea
Biochemical Journal, 2010Co-Authors: Thierry Dulermo, Christine Rascle, Richard Bligny, Elisabeth Gout, Genevieve Billongrand, Pascale CottonAbstract:In order to redefine the Mannitol pathway in the necrotrophic plant pathogen Botrytis cinerea, we used a targeted deletion strategy of genes encoding two proteins of Mannitol metabolism, BcMTDH (B. cinerea Mannitol dehydrogenase) and BcMPD (B. cinerea Mannitol-1-phosphate dehydrogenase). Mobilization of Mannitol and quantification of Bcmpd and Bcmtdh gene transcripts during development and osmotic stress confirmed a role for Mannitol as a temporary and disposable carbon storage compound. In order to study metabolic fluxes, we followed conversion of labelled hexoses in wild-type and ΔBcmpd and ΔBcmtdh mutant strains by in vivo NMR spectroscopy. Our results revealed that glucose and fructose were metabolized via the BcMPD and BcMTDH pathways respectively. The existence of a novel Mannitol phosphorylation pathway was also suggested by the NMR investigations. This last finding definitively challenged the existence of the originally postulated Mannitol cycle in favour of two simultaneously expressed pathways. Finally, physiological and biochemical studies conducted on double deletion mutants (ΔBcmpdΔBcmtdh) showed that Mannitol was still produced despite a complete alteration of both Mannitol biosynthesis pathways. This strongly suggests that one or several additional undescribed pathways could participate in Mannitol metabolism in B. cinerea.
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Novel insights into Mannitol metabolism in the fungal plant pathogen Botrytis cinerea
Biochemical Journal, 2010Co-Authors: Thierry Dulermo, Christine Rascle, Geneviève Billon-grand, Richard Bligny, Elisabeth Gout, Pascale CottonAbstract:In order to redefine the Mannitol pathway in the necrotrophic plant pathogen Botrytis cinerea, we used a targeted deletion strategy of genes encoding two proteins of Mannitol metabolism, a Mannitol dehydrogenase (BcMTDH), and a Mannitol-1-phosphate dehydrogenase (BcMPD). Mobilization of Mannitol and quantification of Bcmpd and Bcmtdh gene transcripts during development and osmotic stress confirmed a role for Mannitol as temporary and disposable carbon storage compound. In order to study metabolic fluxes, we followed conversion of labelled hexoses by wild type and Bcmpd and Bcmtdh mutant strains by in vivo NMR spectroscopy. Our data revealed that glucose and fructose were metabolized via the BcMPD and BcMTDH pathways, respectively. Existence of a novel Mannitol phosphorylation pathway was suggested by NMR investigations for the first time. This last finding definitively challenged the existence of the originally postulated Mannitol cycle in favor of two simultaneously expressed pathways. Finally, physiological and biochemical studies conducted on double deletion mutants (Bcmpd/Bcmtdh) showed that Mannitol was still produced despite a complete alteration of both Mannitol biosynthesis pathways. This strongly suggests that one or several additional undescribed pathways could participate to Mannitol metabolism in B. cinerea.
