Zincum Metallicum, a homeopathic drug, alleviates Zn-induced toxic effects and promotes plant growth and antioxidant capacity in Lepidium sativum L.

In this study, we investigated the effect of the homeopathic drug Zincum Metallicum (ZM) on zinc (Zn) toxicity in the plant species Lepidium sativum L. We focused on growth parameters, Zn uptake and numerous biochemical parameters. Seedlings were hydroponically subjected during 7 days to 0.05, 500, 1000, 1500 and 2000 µM Zn2+, in the absence or presence of 15ch or 9ch ZM. In the absence of ZM, Zn induced negative effect on growth especially at the dose of 2 mM. Zn induced also chlorosis, reduced total chlorophyll and/or carotenoid content and increased the level of malondialdehyde (MDA). Under Zn toxicity (500, 1000 and 1500 µM), the superoxide dismutase (SOD), catalase (CAT), gaiacol peroxidase (GPX) and glutathione reductase (GR) activities were increased or not significantly affected, while at 2000 µM Zn affected the activity of these enzymes. At the highest Zn level (2 mM), proline and total polyphenol and flavonoid contents were markedly increased in leaves and roots of L. sativum. Additionally, ZM supply considerably ameliorated the plant growth, photosynthetic pigment contents and increased non-enzymatic antioxidant molecules and enzymatic activities against Zn-induced oxidative stress. Our data suggest that homeopathic properties of ZM may be efficiently involved in the restriction of Zn-induced oxidative damages, by lowering Zn accumulation and translocation in the leaves and roots of Lepidium sativum L.

The role of nitrogen availability for the salt-tolerance of two different varieties of durum wheat.

Salt stress tolerance of durum wheat was assessed in control and 200 and 300 mM NaCl-exposed seed of two cultivars (BidiAP4 and Azizi). These salt treatments were accompanied by different levels of nitrate (Ca(NO3)2) added to the media (0.1, 3, 10 mM). The data showed that NaCl stress increased Na(+) and Cl(-) contents and lowered K(+) and NO3 (-) levels in seeds of BidiAP4 cultivar. In Azizi seeds exposed to NaCl, Na(+) and K(+) were highly accumulated while low levels of NO3 (-) and Cl(-) were detected. Those findings highlight the difference in the salt stress tolerance of these two durum wheat cultivars also depending on nitrogen (N) availability, Azizi cultivar being less sensitive to NaCl treatment than BidiAP4. These data also suggested a relationship between salt tolerance capacity and enhancement or maintenance of nitrogen and carbon metabolisms enzyme activity.