Seeds of three wheat (Triticum aestivum L.) cultivars included Mahdavi, Pishtaz and Shiraz, were used to investigate the effects of different salinity and auxin concentrations on their germination percent, radicle and hypocotyl length, seedling fresh and dry weight, radicle and hypocotyl dry weight. Results showed that increasing concentrations of NaCl reduced germination percentage, radicle length, hypocotyl length, seedling fresh and dry weight and hypocotyl dry weight. Hypocotyl dry weight increased in seeds only at -0.6 MPa. Auxin increased hypocotyl length, seedling fresh and dry weight and hypocotyl dry weight, but did not influence on seed germination percentage and radicle length. Pishtaz cultivar showed high seed germination percentage, radicle length and hypocotyl length in comparison to other cultivars while Shiraz cultivar had high radicle dry weights and Mahdavi cultivar produced high seedling fresh and dry weights.

Numerous reports find that Cd induces formation of reactive oxygen species (ROS) in plants. However, a general ROS pool is usually studied, without distinction of their production site. In the present study, we applied a mitochondria-specific antioxidant, MitoTEMPO, to elucidate the role of mitochondria-derived ROS in the response of soybean seedlings to short-term (48 h) Cd stress. The obtained results showed that Cd caused a reduction in root length and fresh weight and increase in the level of superoxide anion, hydrogen peroxide, markers of lipid peroxidation (thiobarbituric reactive substances, TBARS) and markers of RNA oxidation (8-hydroxyguanosine, 8-OHG) in seedling roots. Application of MitoTEMPO affected Cd uptake in a dose-dependent manner and diminished the Cd-dependent induction of superoxide anion and lipid peroxidation.