Cadmium (Cd) is a heavy metal present in atmosphere, rocks, sediments, and soils without a known role in plants. It is relatively mobile and can easily enter from soil into groundwater and contaminate the food chain. Its presence in food in excess amounts may cause severe conditions in humans, therefore prevention of cadmium entering the food chain and its removal from contaminated soils are important steps in preserving public health. In the last several years, several approaches for Cd remediation have been proposed, such as the use of soil amendments or biological systems for reduction of Cd contamination. One of the approaches is phytoremediation, which involves the use of plants for soil clean-up. In this review we summarized current data on the use of different plants in phytoremediation of Cd as well as information about different approaches which have been used to enhance phytoremediation. This includes data on the increasing metal bioavailability in the soil, plant biomass, and plant accumulation capacity as well as seed priming as a promising novel approach for phytoremediation enhancing.

Cadmium (Cd) is considered one of the most toxic heavy metals to living organisms, being very persistent in soil and non-biodegradable, thus posing a long-term hazard to plants and humans. In recent years, the application of different molecules at the seed level, known as chemical seed priming, has been studied as a method to improve stress tolerance in plants. In the present study, we tested the effect of hydro-priming and proline priming of lettuce (Lactuca sativa L.) seeds on germination, photosynthetic pigments, and metal metabolism under cadmium stress. Plants primed with proline showed better germination under cadmium stress (100% versus 84% for non-primed and hydro-primed seeds). Priming with 20 mM of proline increased the chlorophyll a and total chlorophyll contents by 40.8% and 18.6%, respectively, while these parameters decreased in other seedlings under Cd stress. Similarly, 20 mM of proline improved the uptake of Zn and Fe in roots under Cd stress. This indicates that 20 mM of proline treatments may be beneficial for maintaining a normal photosynthetic capacity and mineral uptake under Cd stress, but further metabolomics and transcriptomic data should reveal the exact mechanisms of action.

Environmental contamination by polycyclic aromatic hydrocarbons (PAHs) has caused increasing concern because of their known, or suspected, carcinogenic and mutagenic effects. Polycyclic aromatic hydrocarbons occurring in the environment are usually the result of the incomplete combustion of carbon containing materials. The main sources of severe PAHs contamination in soil come from fossil fuels, i.e. production or use of fossil fuels or their products, such as coal tar and creosote. Creosote is used as a wood preservation for railway ties, bridge timbers, pilling and large-sized lumber. It consists mainly of PAHs, phenol and cresol compounds that cause harmful health effects. Research on biodegradation has shown that a special group of microorganisms, the white-rot fungi and brown-rot fungi, has a remarkable potential to degrade PAHs. This paper presents a study of the antifungal activity of 12 selected PAHs against two ligninolytic fungi Hypoxylon fragiforme (white rot) and Coniophora puteana (brown rot). The antifungal activity of PAHs was determined by the disc-diffusion method by measuring the diameter of the zone of inhibition. The results showed that the antifungal activity of the tested PAHs (concentration of 2.5 mmol/L) depends on the their properties such as molar mass, solubility in water, values of log Kow, ionization potential and Henry?s Law constant as well as number of aromatic rings, molecule topology or pattern of ring linkage. Among the 12 investigated PAHs, benzo(k) fluoranthene with five rings, and pyrene with four cyclic condensed benzene rings showed the highest antifungal activity.