Germination and early development ofBrassica napusandBrachypodium distachyongrowth with Zn, Cr (VI), As (V) or Cd: Preliminary results

Abstract

Phytoremediation could reduce heavy metal bioavailability in soils and obtain renewable energy from lands useless. Some fast-growing, high biomass crop species are known to display a significant heavy metal tolerance, particularly those from the genus Brassica. These species could be phytoremediator candidates for recuperate polluted soils with heavy metals. Brachypodium distachyon has also been recently proposed as a model species to develop bioenergy. However, there are no experiments about the tolerance of this plant to metals. The present work reports data concerning the ability of Brachypodium distachyon and Brassica napus seeds to germinate and grow in media containing different doses of Cd, Cr, As and Zn, in order to evaluate their use as energy crops in polluted sites. Biomass reduction and length decreasing were observed as consequence on increasing metal doses in both species, but the effect was different attending to metal and species. The maximum toxicity level was found in plants treated with Cr (VI). Exposures of 30 mg L−1 of Cd and As (V) reduced the shoot elongation by 50% in both species, while root was affected by lower doses than 30 mg L−1. Concentrations of Zn affected neither length, nor biomass of B. distachyon, but shoot and root elongation of B. napus were reduced from the lowest dose of Zn.