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The effects of cadmium stress (0, 25, 50, 75, and 100 mg/L) on morpho-physiological features and selected genes (carotenoid hydroxilase, amidase, GR, bHLH, NRAMP and YSL) expression were demonstrated in Arundo donax L. The plants were assessed for Cd uptake and its effects on chlorophyll and antioxidants after 30 days of exposure. The expression of genes conferring metal tolerance was evaluated after 10 days of Cd exposure. The results showed a maximum Cd uptake in roots (872 mg/kg) followed by stem (734 mg/kg) and leaves (298 mg/kg) at highest supplied Cd concentration. The Cd uptake reduced dry weight, Chla, Chlb, and total Chl contents of giant reed. The SOD, CAT, POD activities and MDA content increased at the maximum Cd concentration over control. The highest genes expression for carotenoid hydroxylase, glutathione reductase and amidase was observed in plants exposed to 100 mg/L. However, differential bHLH gene expression and slightly increased gene expression of NRAMP was noted for different Cd treatments. Amidase expressed under Cd stress which is pioneer report in A. donax. These results provided insights into the mechanisms of A. donax tolerance and survival under Cd Stress. [ABSTRACT FROM AUTHOR]

Combinations of antibiotics occur in terrestrial environments due to excessive prescription, consumption, and disposal and have adverse effects, including crop toxicity. We examined short-term (20-d) toxicity of the fluoroquinolone antibiotics ciprofloxacin, enrofloxacin, levofloxacin, and their mixture in a germination and a greenhouse sand culture study with wheat. We tested the hypothesis that oxidative stress plays a role in toxicity by examining stress products and antioxidants involved in detoxifying reactive oxygen species (ROS) during stress. Germination was unaffected by any antibiotic concentration or mixture used. The highest antibiotic concentrations, 100 and 300 mg L −1 , significantly decreased wheat growth. In 20 days exposure the maximum malondialdehyde production (2.45 μmol g −1 fresh weight), total phenols (16.40 mg g −1 of extract), and total antioxidant capacity (17.74 mg of Vitamin C g −1 of extract) and maximum activities of superoxide dismutase (7.99 units mg −1 protein min −1 ) and ascorbate peroxidase (0.69 μmol ascorbate mg −1 protein min −1 ) significantly increased compared to the control. In contrast, catalase (0.45 mmol H 2 O 2 mg −1 protein min −1 ) and peroxidase (0.0005 units mg −1 protein min −1 ) activity significantly decreased compared to the control. We conclude that high antibiotic concentrations in the plant growth medium reduced wheat growth by causing oxidative stress. The capacity to respond to oxidative stress was compromised by increasingly higher antibiotic concentrations in some enzyme systems. This stress damaged the physiological structure of the young plants and could reduce crop productivity in the long term. Consequently, fluoroquinolone-contaminated water challenges developing countries with constraints on available water for irrigation. [ABSTRACT FROM AUTHOR]