Silicon Differently Affects Apoplastic Binding of Excess Boron in Wheat and Sunflower Leaves.

Monocots and dicots differ in their boron (B) requirement, but also in their capacity to accumulate silicon (Si). Although an ameliorative effect of Si on B toxicity has been reported in various crops, differences among monocots and dicots are not clear, in particular in light of their ability to retain B in the leaf apoplast. In hydroponic experiments under controlled conditions, we studied the role of Si in the compartmentation of B within the leaves of wheat ( L.

Assembly processes under severe abiotic filtering: adaptation mechanisms of weed vegetation to the gradient of soil constraints.

Questions: Effects of soil on vegetation patterns are commonly obscured by other environmental factors; clear and general relationships are difficult to find. How would community assembly processes be affected by a substantial change in soil characteristics when all other relevant factors are held constant? In particular, can we identify some functional adaptations which would underpin such soil-induced vegetation response?

Location: Eastern Serbia: fields partially damaged by long-term and large-scale fluvial deposition of sulphidic waste from a Cu mine; subcontinental/submediterranean climate.

Methods: We analysed the multivariate response of cereal weed assemblages (including biomass and foliar analyses) to a strong man-made soil gradient (from highly calcareous to highly acidic, nutrient-poor soils) over short distances (field scale).