Ecological aspects of heavy metal stress in bryophytes
Abstract
Evolutionary situated between green algae and seed plants, bryophytes were among the first land plants. Unlike seed plants, mosses do not possess a sophisticated root and vascular system. They take up water, nutrients and minerals by the entire surface. This would also include harmful heavy metals. Most bryophytes develop leaflets that only consist of a single layer and they have no protecting cuticle to prevent water loss. However, bryophytes specialise to less favourable habitats with particularly high or low solar irradiation, stagnant moisture or drought and metal contaminated substrates with barren soil. How do these specialists protect themselves and can we possibly find similarities in crop plants to help them grow on less favourable soils as man-made environmental contamination increases?
The matter is complex if all factors on natural metal sites are taken into account. Particularly, the varying content of metal type and concentration in the substrate render precise analyses difficult. Therefore, we cultivate the plants in sterile conditions with gradient contents of metals to provide precise answers on the toxicity of the respective metal, its availability, its impact on growth and morphology as well as its allocation within different tissues.