Toxicity and tolerance of aluminium in vascular plants

摘要: Elevated levels of Al in soil solution may be toxic to plants. The activity monomeric inorganic species is the best measure phytotoxic fraction. Decreasing pH increases exponentially as falls below 4.5. In presence organic matter and acids availability A1 reduced, due complexation. concentration also dependent on dominant clay mineral content. Symptoms toxicity usually first appear roots becoming structurally functionally damaged inefficient absorbing water nutrients. This might disturbance mitosis changed permeability root membranes. Aluminium affects DNA replication, protein synthesis, some enzymes. shoots develop at a later stage poisoning. There an antagonism between macronutrients P, Ca, Mg, K one hand, other. induce deficiency nutrients high nutrient concentrations reduce al toxicity. considerable variation tolerance varieties same species. Several mechanisms for are suggested. Tolerant plants possess active exclusion mechanism or able inactivate within their tissues. induced by plant rhizosphere, exudation chelating agents, low C.E.C. ability withstand compensate other possible mechanisms.