论文部分内容阅读
Plants have evolved a number of different mechanisms for dealing with toxic metals in the environment, and these can involve both avoidance (exclusion of the metal from a plant tissue/organ) or true tolerance, which involves binding and/or sequestration of the metal in an internal compartment.The best characterized mechanism of plant metal tolerance is associated with crop aluminum (Al) tolerance.Al toxicity is a worldwide problem that arises when soil pH values drop to 5 or below; in these acidic soils toxic forms of Al are solubilized into the soil solution, damaging roots and resulting in reduced water and nutrient uptake.The considerable genetic variability for aluminum (Al) tolerance within many crop plant species has been utilized by plant breeders for a number of years to enhance Al tolerance.But beyond this, genetic variability in Al tolerance has been an excellent experimental resource that is being mined by researchers to elucidate the molecular basis for this trait.