Stenocalcic properties in the serpentine-endemic plant Alyssum inflatum Nyárády

Abstract

Serpentine-endemic plants need to grow in substrates with low calcium (Ca). To test this hypothesis, we compared some of the survival-related physiological responses to different concentrations of Ca in Alyssum inflatum (serpentine endemic) and A. lanceolatum (non-serpentine plant). Accordingly, we grew the plants by using solution culture, and the death of root cells was estimated by using Evan’s blue staining. The electrolyte and protein leakage from roots and NADH oxidation activity in the leaked contents were measured as indices of cell death. The results showed that despite the higher growth of shoots in serpentine plants, the high concentration of Ca caused less root growth. Meanwhile, we observed root-cell death, whole-plant death, more electrolyte and protein leakage from roots and a greater NADH oxidation activity in Ca-treated serpentine plants. In non-serpentine plants, both root and shoot showed more growth, whereas no evidence of cell death in the roots was observed. On the basis of the responses to different concentrations of Ca, we introduce the serpentine plant A. inflatum as a stenocalcic that has to live in substrates with a narrow range of Ca concentrations so that it could prevent lethal Ca toxicity. The results demonstrated the reason behind the uneven distribution of the plant on serpentine patches in its habitat.