Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4413352 | Chemosphere | 2009 | 7 Pages |
Abstract
In this study we investigated the acute exposure of the aquatic macrophyte Callitriche obtusangula to the herbicide oxadiazon (Ronstar®). The toxic effects on C. obtusangula were evaluated, 24 h after exposure, by assessing visible necrotic leaf lesions and, 12 h after exposure, via analyses of dead cells and hydrogen peroxide (H2O2) deposits localized by histocytochemical analysis with Trypan blue and 3,3â²-diaminobenzidine (DAB), respectively. As a result, we found that 0.1275 μg Lâ1 a.i. (active ingredient) oxadiazon was the maximum concentration that produced no observable adverse effects (NOAEC) both at leaf and tissue levels, at any considered exposure time. Additionally, we assayed the protective effect of pre-treatment with 0.25 mM N-acetylcysteine (NAC), a cysteine donor, on the damage caused by the toxic herbicidal dose of 6.37 μg Lâ1 a.i to C. obtusangula, correlating the NAC observed protection to the direct H2O2-scavenging and to the enhancement of glutathione parameters. NAC-treated plants showed a fourfold increase in the GSH (reduced glutathione) + GSSG (oxidised glutathione) content (149.2 nmol gâ1 FW) compared to controls (36.1 nmol gâ1 FW); in the NAC + oxadiazon treatments, the GSH + GSSG content was more than fivefold higher (202.1 nmol gâ1 FW). GSH showed a similar trend in NAC and NAC + oxadiazon treatments, being six- (130.0 nmol gâ1 FW) and eightfold (185.0 nmol gâ1 FW) higher, respectively, compared to controls (20.7 nmol gâ1 FW). Accordingly, the GSH/GSSG ratio in NAC- and NAC + oxadiazon-treated plants was significantly increased compared to controls, indicating alleviation of oxidative stress.
Related Topics
Life Sciences
Environmental Science
Environmental Chemistry
Authors
Marcello Iriti, Giulia Castorina, Valentina Picchi, Franco Faoro, Stefano Gomarasca,