Root potassium and hydrogen flux rates as potential indicators of plant response to zinc, copper and nickel stress

摘要: Abstract The practice of phytoremediation often requires that the plants used be exposed to a combined stress multiple heavy metals. While uptake and translocation abilities roots is primary importance, direct effect elevated concentrations metals on root physiology, including ion fluxes, not measured or compared between species in these studies. Four plant (poplar, willow, hemp alfalfa) were selected for long-term project grown hydroponically presence absence metal (zinc, copper nickel), resembling field conditions. Short- potassium hydrogen flux rates with non-invasive selective electrodes. Anatomical observations shoot tissues, as well accumulations made transmission electron microscopy. Biomass, gas exchange parameters pigment all evaluated assess whole-plant effects treatment. Differences short-term induction increased K+ efflux decreased H+ influx from among four reflective declines photosynthetic capacity growth observed poplar but hemp. Tissue degradation patterns poplar, willow alfalfa due are consistent reports literature an imbalance ROS efficient scavenging hydroxyl radicals. Taken together, results indicate measurements can predict sensitivity support their potential use describing root-level responses contaminant conditions sites phytoremediation.