Accumulation and effects in Salix fragilis of an antibacterial

Tercer Congreso Internacional de Salicáceas en Argentina
Comunicación
Accumulation and effects in Salix fragilis of an antibacterial sulfonamide
Lucia Michelini, Franco Meggio1, Paolo Paiero2 and Rossella Ghisi*
Department of Biotecnologie Agrarie, University of Padova, Italy
1
Department of Agronomia Ambientale e Produzioni Vegetali, University of Padova, Italy
2
Department of Land and Agroforest Environments – University of Padova - Italy
The application of contaminated manure to fertilize agricultural soils is among the major
routes through which antibacterial sulfonamides (SAs) enter the environment. SAs can be
easily leached into groundwater, due to their persistence and low sorption to soil constituents.
In effect, the presence of these compounds in soil, surface water and groundwater are
frequently reported. Previous results showed that barley plants are able to accumulate high
amount of SAs from nutrient solutions. Salix is currently under intensive research for its
potential use in soil phytoremediation. In this study we evaluated the possibility to use
willows to remediate soils/groundwater contaminated with SAs, by studying both the ability
of these plants to absorb sulfadimetoxine (SDM) and to tolerate it. The experiments were
conducted with Salix fragilis cuttings grown hydroponically in a climate chamber. Once
rooted and with leaves, plants were exposed to different concentrations of SDM (0.04 to 3
mM) for a month. At fixed time intervals photosynthetic (LI-COR 6400) and growth
parameters were measured. At the end of the experiments plants were analysed for their
content in sulfadimetoxine. Photosynthetic pigments and chlorophyll fluorescence were also
analysed to obtain further information on response of willow to sulfonamides.
Results show that Salix fragilis growth (leaf and stem length), photosynthetic pigment
contents, chlorophyll fluorescence parameters and transpiration are not influenced by the
treatment, however, the measures of CO2 fixation during leaf development indicate a lower
photosynthetic rate in treated plants than in controls, which must be studied. Roots
accumulated high amount of SDM, whereas leaves did not show the presence of the
antibacterial substance.
In conclusion our results indicate that willow is a promising specie in the phytoremediation of
sulfonamides, however further researches are needed to analyse plant response to lower, more
realistic sulfonamide concentrations and to evaluate the response of different Salix species.
Keywords: antibacterial, phytoremediation, soil pollution, water pollution, willow
Tercer Congreso Internacional de Salicáceas en Argentina
Comunicación
*presenting author, Department of Biotecnologie Agrarie, University of Padova, Viale
dell'Università 16, 35020 Legnaro (PD), ITALY, Tel +39 049 8272910
rossella.ghisi@unipd.it