| Project/Area Number |
26660047
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Plant nutrition/Soil science
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| Research Institution | Tohoku University |
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Principal Investigator |
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| Project Period (FY) |
2014-04-01 – 2016-03-31
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| Project Status |
Completed (Fiscal Year 2015)
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| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
Fiscal Year 2014: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
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| Keywords | 土壌生物 / 根圏窒素循環 / 脱窒 / N2O / フザリウム |
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| Outline of Final Research Achievements |
Nitrous oxide (N2O) is a key atmospheric greenhouse gas that affects global warming and the destruction of stratospheric ozone. Legume field is one of major sources of N2O emission from degraded root nodules. However, soil microorganisms emitting N2O other than bradyrhiozbial endosymbionts in the rhizosphere remain unknown. N2O isotopomer analysis is useful tool to discriminate fungal and bacterial N2O emissions. Generally, the site preference values of N2O (N2O-SP) produced by fungal denitrification are higher than those of bacterial denitrification. The addition of nitrite instead of nitrate to soybean nodulated roots significantly increased N2O-SP. Moreover, the mutation of nirK gene (encoding dissimilatory nitrite reductase) in symbiotic bradyrhizobia significantly increased N2O-SP in the presence of nitrite. These results indicate that nitrite-utilizing N2O emission via fungal denitrification occurred in the rhizosphere.
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