Project No. 2417

STANDARD PROJECT

Primary Supervisor

Dr Marc Dumont – University of Southampton

Co-Supervisor(s)

Dr Tomislav Cernava – University of Southampton

Dr Matevz Papp-Rupar – NIAB East Malling

Dr Louise Robinson-Boyer – NIAB East Malling

Summary

Rice is a staple food and critical source of calories and nutrients for more than half the world’s population.

Rice cultivation is also a major source of atmospheric methane, which is a greenhouse gas 80-times as potent as carbon dioxide at trapping heat in the atmosphere. Methane concentrations have increased dramatically in the atmosphere since the industrial revolution and are responsible for approximately 20% of global warming. More than 100 countries including the UK have signed up to the Global Methane Pledge, which was launched at COP26 and aims to curb methane release to the atmosphere.

Aerobic methanotrophs are bacteria that can use methane as a sole source of carbon and energy for growth. They are common in rice field soil and have been found in the rhizosphere and endosphere of rice plants. Some strains can fix atmospheric nitrogen into ammonia that has the potential to improve rice plant growth and grain yields. Therefore, methanotrophs associated with rice have the potential to both mitigate methane release to the atmosphere and to improve rice yields. However, methanotroph abundances and activities are typically lower in the rhizosphere and endosphere than would be expected based on carbon and oxygen availability, suggesting their growth might be constrained by plant-specific factors.

The aims of the project are to characterize the diversity of methanotrophs associated with different rice cultivars, to identify plant compounds that inhibit methanotrophs, and to explore the potential to enhance plant colonization by nitrogen-fixing methanotrophs. We will use a variety of approaches, including analyses of metagenomic datasets, activity assays of rice root exudates on methanotrophic bacteria, and the isolation and inoculation of rice plants with methanotroph isolates. This project could lead to transformative technologies for the cultivation of rice with lower requirement for nitrogen fertilizer input and lead to more sustainable agriculture.