Regression analysis of the fraction of leaf N allocated to the cell wall (<i>P</i>_CW) with leaf N allocated to Rubisco (<i>P</i>_R) in four species seedling leaves.

The determination coefficient (R2) and P-value were also shown. The shaded zone was drawn according to this hypothesis: when PCW was 0.300 g g–1, the rest (0.700 g g–1) were soluble and thylakoid protein, Rubisco represented one quarter to one-third of the N in soluble and thylakoid protein, PR valued 0.175–0.233 g g–1(right side of shaded zone). When PCW was valued 0.000 g g–1 in limiting case (does not exist in reality), all the rest (1.000 g g–1) were soluble and thylakoid protein, PR valued 0.250–0.333 g g–1(left side of shaded zone). For more information see Harrison et al. [21]. The lines fitted separately for four species were significantly different (P PR as a dependent variable, tree species as fixed factors, and PCW as a covariate.