OPENAIRE OpenAire Sygma Bielefeld Academic Search Engine (BASE) e-Prints Soton Cranfield CERES UnpayWall Crossref Microsoft Academic Graph Europe PubMed Central PubMed Central European Union Open Data Portal https://eprints.soton.ac.uk/433011/1/_system_appendPDF_proof_hi_4.pdf https://eprints.soton.ac.uk/433011/2/Kirk_et_al_2019_Plant_Cell_Environment.pdf https://onlinelibrary.wiley.com/doi/pdf/10.1111/pce.13638 https://doi.org/2966605969 Plant, Cell &amp; Environment Open Access 2019-08-05 Abstract<p>The growth of rice in submerged soils depends on its ability to form continuous gas channels￢ﾀﾔaerenchyma￢ﾀﾔthrough which oxygen (O2) diffuses from the shoots to aerate the roots. Less well understood is the extent to which aerenchyma permits venting of respiratory carbon dioxide (CO2) in the opposite direction. Large, potentially toxic concentrations of dissolved CO2 develop in submerged rice soils. We show using X￢ﾀﾐray computed tomography and image￢ﾀﾐbased mathematical modelling that CO2 venting through rice roots is far greater than thought hitherto. We found rates of venting equivalent to a third of the daily CO2 fixation in photosynthesis. Without this venting through the roots, the concentrations of CO2 and associated bicarbonate (HCO3￢ﾈﾒ) in root cells would have been well above levels known to be toxic to roots. Removal of CO2 and hence carbonic acid (H2CO3) from the soil was sufficient to increase the pH in the rhizosphere close to the roots by 0.7 units, which is sufficient to solubilize or immobilize various nutrients and toxicants. A sensitivity analysis of the model showed that such changes are expected for a wide range of plant and soil conditions.</p 580 0106 biological sciences 0301 basic medicine 570 Oryza Original Articles Carbon Dioxide 15. Life on land Models, Biological Plant Roots 01 natural sciences 6. Clean water biological transport X‐ray computed tomography Soil 03 medical and health sciences 13. Climate action biological models Tiina Roose, Guy J. D. Kirk, Marie-Cecile Affholder, Andrea Boghi, Andrea Boghi, Samuel D. Keyes, J. Heppell, 2019-08-19 journalpaper Abstract<p>The growth of rice in submerged soils depends on its ability to form continuous gas channels￢ﾀﾔaerenchyma￢ﾀﾔthrough which oxygen (O2) diffuses from the shoots to aerate the roots. Less well understood is the extent to which aerenchyma permits venting of respiratory carbon dioxide (CO2) in the opposite direction. Large, potentially toxic concentrations of dissolved CO2 develop in submerged rice soils. We show using X￢ﾀﾐray computed tomography and image￢ﾀﾐbased mathematical modelling that CO2 venting through rice roots is far greater than thought hitherto. We found rates of venting equivalent to a third of the daily CO2 fixation in photosynthesis. Without this venting through the roots, the concentrations of CO2 and associated bicarbonate (HCO3￢ﾈﾒ) in root cells would have been well above levels known to be toxic to roots. Removal of CO2 and hence carbonic acid (H2CO3) from the soil was sufficient to increase the pH in the rhizosphere close to the roots by 0.7 units, which is sufficient to solubilize or immobilize various nutrients and toxicants. A sensitivity analysis of the model showed that such changes are expected for a wide range of plant and soil conditions.</p Soil carbon dioxide venting through rice roots 2966605969 646809