Influence of elevated [CO₂] on flow of elements in a rice plant during growth, and genetic improvement to prevent elemental reduction in grains.

(a) Change in elemental flow in rice (“Koshihikari”) under elevated [CO2] as compared with ambient [CO2]. Arrows indicate the direction of elemental flow: blue shows an increase, red a decrease, and grey no change under elevated [CO2] versus ambient [CO2]. Purple arrows indicate that the direction of flow was reversed by CO2 treatment. The extent of the change in flow is indicated by arrow width; the part of the plant showing the greatest changes for each element is represented by the widest arrow. Abbreviations are defined in Fig 1B. (b) Percentage change in the nitrogen (protein) and sulfur content of grains of wild-type “Koshihikari” and a chromosomal segment substitution line containing rg518 or GS319 grown under elevated [CO2] relative to ambient [CO2].