ABSTRACT
Effectiveness of iron (Fe3+)-citrate and Fe3+-EDTA (ethylenediaminetetraacetic acid) in reducing arsenic (As)-toxicity in rice was evaluated. The treatments: 1) 0 µM As + 10 µM Fe3+-citrate (control), 2) 13.4 µM As + 10 µM Fe3+-citrate (As-treated), 3) 13.4 µM As + 10 µM Fe3+-citrate + 40 µM Fe3+-citrate (additional Fe3+-citrate), and 4) 13.4 µM As + 10 µM Fe3+-citrate + 40 µM Fe3+-EDTA (additional Fe3+-EDTA) were studied for 14 days. Chlorosis was found in the young leaves of the As-treated plants. Additional Fe3+-citrate failed to remediate the chlorosis, however, additional Fe3+-EDTA removed the chlorosis almost completely, indicating that the effectiveness of Fe3+-EDTA was much higher than Fe3+-citrate. The Fe3+-EDTA treated plants were greener than the additional Fe3+-citrate treated plants. Iron concentration in the shoots of additional Fe3+-EDTA plants was much higher than that of additional Fe3+-citrate plants, indicating that Fe3+-EDTA might have been more readily available to the plants roots than Fe3+-citrate.
Funding
The first author wishes to express appreciation to the Ministry of Education, Science, Culture, and Sports, Government of Japan for financial support.