Silicon

Abstract

Silicon is present in plants in amounts equivalent to those of such macronutrient elements as calcium, magnesium, and phosphorus, and in grasses often at higher levels than any other inorganic constituent. Yet except for certain algae, including prominently the diatoms, and the Equisetaceae (horsetails or scouring rushes), it is not considered an essential element for plants. As a result it is routinely omitted from formulations of culture solutions and considered a nonentity in much of plant physiological research. But silicon-deprived plants grown in conventional nutrient solutions to which silicon has not been added are in many ways experimental artifacts. They are often structurally weaker than silicon-replete plants, abnormal in growth, development, viability, and reproduction, more susceptible to such abiotic stresses as metal toxicities, and easier prey to disease organisms and to herbivores ranging from phytophagous insects to mammals. Many of these same conditions afflict plants in silicon-poor soils-and there are such. Taken together, the evidence is overwhelming that silicon should be included among the elements having a major bearing on plant life.

Is the effect of silicon on rice uptake of arsenate (AsV) related to internal silicon concentrations, iron plaque and phosphate nutrition?

“…This result suggests that Si may play a beneficial role in alleviating As toxicity. Positive effects of Si on plant growth under biotic and abiotic stresses have been reported elsewhere by Epstein (1994Epstein ( , 1999, and it is also well known that Si may improve plant growth at the late growth stage, since about 66% of silicon in the whole plant has been showed to be absorbed during the reproductive stage . The addition of Si to the pretreatment or uptake solution significantly decreased shoot and root As concentrations, suggesting that both external and internal Si could affect As uptake.…”

“…Although silicon (Si) has not been listed among the essential elements for higher plants, it is well known that Si is beneficial for healthy growth and development of many plant species, especially graminaceous plants such as rice (Oryza sativa L.) (Lian, 1976;Liang et al, 1994;Epstein, 1994Epstein, , 1999. Si is also well known to be effective in alleviating abiotic stresses in higher plants (Hodson and Evans, 1995;Rogalla and Römheld, 2002;Liang et al, 2003Liang et al, , 2005.…”

Structure and mechanical properties of selected protective systems in marine organisms

“…Silica (SiO 2 ) is most commonly expressed within the biological materials of sponges and diatoms [76][77][78][79][80][81], and is generally found in its amorphous form [76][77][78][79]. The biomineralization of SiO 2 follows different processes in different organisms.…”

Growth conditions, elemental accumulation and induced physiological changes in Chinese cabbage

“…Thus total B and Ca, accumulated with crop age, while the Al, Ag and Si concentrations, together with the Si soluble fraction, dipped possibly by dilution with plant growth. The higher uptake of B and Si in T 1 and T 2 may detoxify Al by coprecipitation with Al codeposited with Si, as a defence mechanism against Al (Epstein, 1999).…”