This suggests that the inhi- bition of net assimilation of leaves was not only due to stomata factors,
but also due to non-stomata factors.
The improvement of photosynthetic ability by added silicon under salt stress should be associated with the positive effect of silicon on the plant growth, which resulted from the reduction in chloride accumulation in the shoot. In order to exclude the “dilution” effect of growth on the con- centrations of chloride and sodium in the shoot, we determined the shoot relative growth rate in saline conditions. The relative growth rate of shoot was only increased by silicon which was provided with NaCl simultaneously, and the increase in relative growth rate was less than the decreases in sodium and chloride concentrations (Table 2). Moreover, silicon pretreatment before salt stress slightly, but did not significantly increase the relative growth rate of shoot as compared to salt treatment alone. Therefore, the “dilution” effect of shoot growth could be excluded for silicon-mediated decrease of chloride accumulation in rice.