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Phytoremediation combined with suitable microorganisms and biodegradable chelating agents can be a means of reclaiming lands contaminated by toxic heavy metals. We investigated the ability of a lead- and cadmium-resistant bacterial strain (JB12) and the biodegradable chelator ethylenediamine- N, N′-disuccinic acid (EDDS) to improve absorption of these metals from soil by tall fescue and red clover. Strain JB12 was isolated from contaminated soil samples, analysed for lead and cadmium resistance, and identified as Burkholderia cepacia. Tall fescue and red clover were grown in pots to which we added JB12, ( S, S)-EDDS, combined JB12 and EDDS, or water only. Compared with untreated plants, the biomass of plants treated with JB12 was significantly increased. Concentrations of lead and cadmium in JB12-treated plants increased significantly, with few exceptions. Plants treated with EDDS responded variably, but in those treated with combined EDDS and JB12, heavy metal concentrations increased significantly in tall fescue and in the aboveground parts of red clover. We conclude that JB12 is resistant to lead and cadmium. Its application to the soil improved the net uptake of these heavy metals by experimental plants. The potential for viable phytoremediation of lead- and cadmium-polluted soils with tall fescue and red clover combined with JB12 was further enhanced by the addition of EDDS. [ABSTRACT FROM AUTHOR]

There is a growing interest in using plants to provide low-cost ecosystem services in a diversity of environments (e.g., polluted, degraded, urban). These utilizations of plants are collectively referred to as phytotechnologies. Many plants used in phytotechnological applications are naturally found to associate with mycorrhizal fungi. These fungal associates can provide numerous ecosystem services, or help plants to do so. There is thus an obvious incentive to better understand how mycorrhizal symbioses can assist phytotechnologies. For some phytotechnological applications, the benefits of using mycorrhizal fungi seem well-established, while for others, these benefits are either uncertain or simply unexplored. In all cases, a trait-based, mechanistic understanding of what allows mycorrhizal fungi to provide any benefit/service is urgently needed. This will help to develop reliable, mycorrhiza-assisted phytotechnologies in the future, while also improving our fundamental understanding of the evolution of stress tolerance in these important plant-associated symbionts. [ABSTRACT FROM AUTHOR]

Pesticides based on zinc (Zn) salts used for intensive agriculture continuously accumulate in the soil. Using the genus Salix is a viable long-term solution to extract excess Zn from soil. Three Salix spp. clones from the southern Mediterranean region were rated for their tolerance levels to four different concentrations of ZnSO4·7H2O (0.4, 250, 500, and 750 μmol·L−1). At the end of a 45-day period, many ecophysiological variables were measured. Following treatments, stress response to Zn varied among genotypes. These marked clonal variations were expressed as toxicity symptoms, physiological disturbances, and reduced growth. Our results suggest that Salix clones could be used as agroforestry model to counteract Zn accumulation in agricultural soils, allowing them to maintain their agronomic value, fertility, and productive potential. [Journal translation] [ABSTRACT FROM AUTHOR]