Toxic effect of tetracycline exposure on growth, antioxidative and genetic indices of wheat (Triticum aestivum L.)

Introduction More attention has been paid to tetracycline contamination in view of its rapid increasing concentration in the environment. Therefore, it is important to set up rapid, simple, and accurate methods for monitoring tetracycline ecotoxicity. Methods In the present study, a hydroponics experiment was conducted to examine toxic effects of tetracycline at the concentration range of 0.5 to 300 mg L-1 on growth, antioxidative, and genetic indices of wheat (Triticum aestivum L.). Results The results indicated that tetracycline at 0.5-10 mg L-1 could stimulate seed germination, cell mitotic division, and growth of wheat seedlings and did not induce a significant increase in the activity of antioxidative enzymes. However, tetracycline at the high concentrations (10-300 mg L-1) could significantly inhibit these parameters in the concentration-dependent manner, including germination percentage (a parts per thousand yen100 mg L-1), shoot height (a parts per thousand yen100 mg L-1), root length (a parts per thousand yen50 mg L-1), and mitotic index (a parts per thousand yen50 mg L-1), and increased the activity of antioxidative enzymes (a parts per thousand yen25 mg L-1) in the dose-dependent manner, including superoxide dismutase, catalase, and peroxidase. Tetracycline at 5 mg L-1 and above significantly augmented chromosome aberration frequency and malondialdehyde (MDA) content. On the other hand, MDA has positive correlation with the inhibition rates of seed germination, root length, shoot length, mitotic index, and antioxidative enzyme activities. Conclusion Tetracycline may have potential physiological, biochemical, and genetic toxicity to plant cells, and chromosome aberration and MDA might be sensitive bioindicators for tetracycline contamination than the other plant characteristics.