Figure 4
Effects of P toxicity on Rubisco content and activation by Rubisco
activase (RCA). (a) shows the leaf nitrogen content in rice leaves, and
(b) shows the Rubisco content in rice leaves (n = 3-4). Rubisco
activation was calculated from the ratio of the initial to maximum
Rubisco activity (c), and the carbamylation potential was calculated
from the ratio of the total to the maximum Rubisco activity (d) (n =
3-5). The white and dark gray bars indicate the results of the leaves
sampled under illumination and at night, respectively, under the
control-Pi conditions. (e) shows the result of the western-blot
analysis, which targets RCA in rice leaves. Red arrows and Greek
characters indicate the isoforms of RCA. Each sample was loaded on the
leaf area basis (0.02 cm2). (f) and (g) show the
relative content of the total RCA and each isoform evaluated from the
western-blot analysis. The RCA content in the control-Pi plants, set as
“1” and the relative content is shown. The black, red, and gray
characters above the bars indicate the statistical results of theα, β, β* isoforms, respectively. (h) and (i) show
the isoform ratio between α /β and β */β (n =
4). These results are expressed as mean ± SD. Different alphabets
indicate the significant difference among different Pi application
conditions (Tukey-Kramer’s HSD test, p < 0.05).