Fig 1.
Influence of elevated [CO2] on elemental content in crops.
(a) Comparison of changes in the content of all tested elements under elevated [CO2] between brown rice (black circles) and polished grains (red diamonds). Data are presented as the mean and one side of 95% confidence intervals (bars) of nine varieties. Red and blue backgrounds denote a significant difference (P < 0.05), where previous work on brown grain has under- or overestimated, respectively, elemental changes in polished grains. For Al, Si, and Br, the values were off the scale of the y axis, as indicated by the wavy line. (b) Time-dependent changes in the elemental content of each part of the rice plant under elevated [CO2]. Data are presented as the mean. (c) Percentage change in the elemental content of polished grains and plant body (“straw”) of rice (“Koshihikari”). (d) Estimated change in elemental content in feed crops under elevated [CO2]. (e) Estimated change in elemental content in leaf vegetables under elevated [CO2]. The raw data are provided in Table 1 and S4 Table. In (c)-(e), essential elements are arranged in decreasing order of intake requirement. Elements that decreased significantly (P < 0.05) under elevated [CO2] are shown in red.
Fig 2.
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].
Table 1.
Effect of elevated [CO2] on elemental content in feed crops.
ND means no data. *Significant at P<0.05. The values mean the ratio of elemental content under elevated [CO2] to content under ambient condition (%).
Table 2.
List of genes for element transport that is affected by elevated [CO2].