Interactions of Silicon With Essential and Beneficial Elements in Plants.

Silicon (Si) is not classified as an essential element for plants, but numerous studies have demonstrated its beneficial effects in a variety of species and environmental conditions, including low nutrient availability. Application of Si shows the potential to increase nutrient availability in the rhizosphere and root uptake through complex mechanisms, which still remain unclear. Silicon-mediated transcriptional regulation of element transporters for both root acquisition and tissue homeostasis has recently been suggested as an important strategy, varying in detail depending on plant species and nutritional status.

Role of magnesium in carbon partitioning and alleviating photooxidative damage.

Magnesium (Mg) deficiency exerts a major influence on the partitioning of dry matter and carbohydrates between shoots and roots. One of the very early reactions of plants to Mg deficiency stress is the marked increase in the shoot-to-root dry weight ratio, which is associated with a massive accumulation of carbohydrates in source leaves, especially of sucrose and starch. These higher concentrations of carbohydrates in Mg-deficient leaves together with the accompanying increase in shoot-to-root dry weight ratio are indicative of a severe impairment in phloem export of photoassimilates from source leaves.

Germanium-68 as an adequate tracer for silicon transport in plants. Characterization of silicon uptake in different crop species.

A basic problem in silicon (Si) uptake studies in biology is the lack of an appropriate radioactive isotope. Radioactive germanium-68 ((68)Ge) has been used previously as a Si tracer in biological materials, but its suitability for the study of Si transport in higher plants is still untested. In this study, we investigated (68)Ge-traced Si uptake by four crop species differing widely in uptake capacity for Si, including rice (Oryza sativa), barley (Hordeum vulgare), cucumber (Cucumis sativus), and tomato (Lycopersicon esculentum).