During the development of this project, I used a multidisciplinary approach that combined state-of-the-art physiological measurements, including microsensing technology, gas trace laser analyzers, gas chromatography, mass spectrometry, microscopic characterization of plant tissues, and mathematical modelling. I evaluated different rice genotypes and grew them under various conditions to induce specific responses in root traits. Such responses include increased root porosity and roots with larger root diameters, which increase the area available for gas diffusion inside tissues; the development of root apoplastic barriers, thereby increasing resistances to gas diffusion; and the development of root systems with marked variations in adventitious or lateral roots, resulting in overall variations in resistances to gas diffusion. In addition to methodological developments for studying gas dynamics in plant tissues, the main outcome of this project was the finding that root traits are the primary resistant points restricting the diffusion of CH4 from the medium into the plants and, subsequently, to the atmosphere.