Chapter 6 - Silicon uptake and accumulation in plants

Abstract

This chapter summarizes the research on silicon (Si) uptake and accumulation mainly in rice. The variation among plant species in the Si content of the top is attributed to the difference in the mode of Si uptake. The rice roots have the high ability to take up Si. The culture of rice for two days in tap water results in a significant decrease of Si concentration in the tap water and indicates that Si is removed by rice from the tap water effectively. The chemical form of soluble Si taken by the plants varies depending on the pH of the solution. The uptake of Si by rice roots is not inducible. Transpiration plays a certain role in translocation and accumulation of Si to the tops of rice. The Si concentration is high in leaf blades and husks where the transpiration rate is high. Although rice roots play an important role in active uptake of Si, the Si content in the roots is much lower than that in the tops. Therefore, Si taken up by the roots is supposed to be translocated to the shoot along with the transpiration steam. The effect of nutrient ions on the Si uptake is very small. Si uptake by rice is aerobic metabolism-dependent active process. The effect of metabolic inhibitors on the uptake of Si and phosphorus (P) uptake varies with the inhibitor.