Novel species of N2O-reducing rhizobia: exploring the host range and N2O mitigation potential

• Project/Area Number: 24K17806
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 38010:Plant nutrition and soil science-related
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: ラトゥ サフィラタサナーバス 東京農工大学, (連合)農学研究科(研究院), 特任助教 (00985004)
• Project Period (FY): 2024-04-01 – 2027-03-31
• Project Status: Granted (Fiscal Year 2024)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2026: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2025: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2024: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: Rhizobia / Legumes / Nodules / N2-fixing / N2O-reduction

Outline of Research at the Start

Leguminous plants establish a beneficial N2-fixing symbiosis with rhizobia, thus holds environmental benefits by limiting the reliance on the synthetic N fertilizers. However, the interaction leads to the production of a potent nitrous oxide, particularly in the postharvest stage. Intriguingly, certain rhizobia have denitrifying enzyme system that includes an N2O reductase and is able to convert N2O into harmless N2. Denitrification among rhizobia is rare. This study aims to identify novel rhizobia species with both efficient N2 fixation and N2O reduction in a broad host range of legume crops.