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An S-(hydroxymethyl)glutathione dehydrogenase is involved in conidiation and full virulence in the rice blast fungus Magnaporthe oryzae.

Zhang Z, Wang J, Chai R, Qiu H, Jiang H, Mao X, Wang Y, Liu F, Sun G - PLoS ONE (2015)

Bottom Line: Here, we characterized an S-(hydroxymethyl)-glutathione dehydrogenase gene in M. oryzae, MoSFA1, the homologs of which are involved in NO metabolism by specifically catalyzing the reduction of S-nitrosoglutathione (GSNO) in yeasts and plants.Notably, the mutants showed severe reduction of conidiation and appressoria turgor pressure, as well as significantly attenuated the virulence on rice cultivar CO-39.MoSFA1 deletion mutants displayed hypersensitivity to different oxidants, reduced activities of superoxide dismutases and peroxidases, and lower glutathione content in cells, compared with the wild type.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China; State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.

ABSTRACT
Magnaporthe oryzae is a hemibiotrophic fungal pathogen that causes rice blast disease. A compatible interaction requires overcoming plant defense responses to initiate colonization during the early infection process. Nitric oxide (NO) plays important roles in defense responses during host-pathogen interactions. Microbes generally protect themselves against NO-induced damage by using enzymes. Here, we characterized an S-(hydroxymethyl)-glutathione dehydrogenase gene in M. oryzae, MoSFA1, the homologs of which are involved in NO metabolism by specifically catalyzing the reduction of S-nitrosoglutathione (GSNO) in yeasts and plants. As expected from the activities of S-(hydroxymethyl)glutathione dehydrogenase in formaldehyde detoxification and GSNO reduction, MoSFA1 deletion mutants were lethal in formaldehyde containing medium, sensitive to exogenous NO and exhibited a higher level of S-nitrosothiols (SNOs) than that of the wild type. Notably, the mutants showed severe reduction of conidiation and appressoria turgor pressure, as well as significantly attenuated the virulence on rice cultivar CO-39. However, the virulence of MoSFA1 deletion mutants on wounded rice leaf was not affected. An infection assay on barley leaf further revealed that MoSFA1 deletion mutants exhibited a lower infection rate, and growth of infectious hyphae of the mutants was retarded not only in primary infected cells but also in expansion from cell to cell. Furthermore, barley leaf cell infected by MoSFA1 deletion mutants exhibited a stronger accumulation of H2O2 at 24 and 36 hpi. MoSFA1 deletion mutants displayed hypersensitivity to different oxidants, reduced activities of superoxide dismutases and peroxidases, and lower glutathione content in cells, compared with the wild type. These results imply that MoSFA1-mediated NO metabolism is important in redox homeostasis in response to development and host infection of M. oryzae. Taken together, this work identifies that MoSFA1 is required for conidiation and contributes to virulence in the penetration and biotrophic phases in M. oryzae.

No MeSH data available.


Related in: MedlinePlus

The activity of antioxidant enzymes and the content of GSH in tested M. oryzae strains.Activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) and the content of reduced GSH in the tested strains were determined using assay kits purchased from Nanjing Jiancheng Bioengineering Institute (Nanjing, China). The experiments were performed in triplicate. Error bars represent SD. Asterisks in each data column indicate significant differences at p = 0.05.
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pone.0120627.g009: The activity of antioxidant enzymes and the content of GSH in tested M. oryzae strains.Activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) and the content of reduced GSH in the tested strains were determined using assay kits purchased from Nanjing Jiancheng Bioengineering Institute (Nanjing, China). The experiments were performed in triplicate. Error bars represent SD. Asterisks in each data column indicate significant differences at p = 0.05.

Mentions: Considering the hypersensitivity of MoSFA1 deletion mutants to oxidants, MoSFA1 were presumed to involve in redox homeostasis in cells. Superoxide dismutases, catalases, and peroxidases provide the cells with highly efficient machinery for detoxifying ROS [35]. GSH acts as a radical scavenger and an electron donor, and the concentration of GSH in cells is important to keep redox homeostasis [36]. Our data showed that the activities of SOD and POD in MoSFA1 deletion mutant had significantly lower levels than those of the wild type, but CAT activity was not different from that of the wild type. In addition, the concentration of reduced GSH in MoSFA1 deletion mutant was significantly diminished in cells (Fig. 9).


An S-(hydroxymethyl)glutathione dehydrogenase is involved in conidiation and full virulence in the rice blast fungus Magnaporthe oryzae.

Zhang Z, Wang J, Chai R, Qiu H, Jiang H, Mao X, Wang Y, Liu F, Sun G - PLoS ONE (2015)

The activity of antioxidant enzymes and the content of GSH in tested M. oryzae strains.Activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) and the content of reduced GSH in the tested strains were determined using assay kits purchased from Nanjing Jiancheng Bioengineering Institute (Nanjing, China). The experiments were performed in triplicate. Error bars represent SD. Asterisks in each data column indicate significant differences at p = 0.05.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4368689&req=5

pone.0120627.g009: The activity of antioxidant enzymes and the content of GSH in tested M. oryzae strains.Activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) and the content of reduced GSH in the tested strains were determined using assay kits purchased from Nanjing Jiancheng Bioengineering Institute (Nanjing, China). The experiments were performed in triplicate. Error bars represent SD. Asterisks in each data column indicate significant differences at p = 0.05.
Mentions: Considering the hypersensitivity of MoSFA1 deletion mutants to oxidants, MoSFA1 were presumed to involve in redox homeostasis in cells. Superoxide dismutases, catalases, and peroxidases provide the cells with highly efficient machinery for detoxifying ROS [35]. GSH acts as a radical scavenger and an electron donor, and the concentration of GSH in cells is important to keep redox homeostasis [36]. Our data showed that the activities of SOD and POD in MoSFA1 deletion mutant had significantly lower levels than those of the wild type, but CAT activity was not different from that of the wild type. In addition, the concentration of reduced GSH in MoSFA1 deletion mutant was significantly diminished in cells (Fig. 9).

Bottom Line: Here, we characterized an S-(hydroxymethyl)-glutathione dehydrogenase gene in M. oryzae, MoSFA1, the homologs of which are involved in NO metabolism by specifically catalyzing the reduction of S-nitrosoglutathione (GSNO) in yeasts and plants.Notably, the mutants showed severe reduction of conidiation and appressoria turgor pressure, as well as significantly attenuated the virulence on rice cultivar CO-39.MoSFA1 deletion mutants displayed hypersensitivity to different oxidants, reduced activities of superoxide dismutases and peroxidases, and lower glutathione content in cells, compared with the wild type.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China; State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.

ABSTRACT
Magnaporthe oryzae is a hemibiotrophic fungal pathogen that causes rice blast disease. A compatible interaction requires overcoming plant defense responses to initiate colonization during the early infection process. Nitric oxide (NO) plays important roles in defense responses during host-pathogen interactions. Microbes generally protect themselves against NO-induced damage by using enzymes. Here, we characterized an S-(hydroxymethyl)-glutathione dehydrogenase gene in M. oryzae, MoSFA1, the homologs of which are involved in NO metabolism by specifically catalyzing the reduction of S-nitrosoglutathione (GSNO) in yeasts and plants. As expected from the activities of S-(hydroxymethyl)glutathione dehydrogenase in formaldehyde detoxification and GSNO reduction, MoSFA1 deletion mutants were lethal in formaldehyde containing medium, sensitive to exogenous NO and exhibited a higher level of S-nitrosothiols (SNOs) than that of the wild type. Notably, the mutants showed severe reduction of conidiation and appressoria turgor pressure, as well as significantly attenuated the virulence on rice cultivar CO-39. However, the virulence of MoSFA1 deletion mutants on wounded rice leaf was not affected. An infection assay on barley leaf further revealed that MoSFA1 deletion mutants exhibited a lower infection rate, and growth of infectious hyphae of the mutants was retarded not only in primary infected cells but also in expansion from cell to cell. Furthermore, barley leaf cell infected by MoSFA1 deletion mutants exhibited a stronger accumulation of H2O2 at 24 and 36 hpi. MoSFA1 deletion mutants displayed hypersensitivity to different oxidants, reduced activities of superoxide dismutases and peroxidases, and lower glutathione content in cells, compared with the wild type. These results imply that MoSFA1-mediated NO metabolism is important in redox homeostasis in response to development and host infection of M. oryzae. Taken together, this work identifies that MoSFA1 is required for conidiation and contributes to virulence in the penetration and biotrophic phases in M. oryzae.

No MeSH data available.


Related in: MedlinePlus