| 叶面喷施纳米MnO2对水稻富集镉的影响机制 |
| 摘要点击 2441 全文点击 810 投稿时间：2020-06-30 修订日期：2020-08-04 |
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| 中文关键词 水稻 镉 富集 叶面喷施 纳米MnO2 |
| 英文关键词 rice cadmium enrichment foliar spraying nano-MnO2 |
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| 中文摘要 |
| 镉（Cd）容易被水稻富集，从而造成稻米中Cd含量超标，严重威胁人类健康.锰（Mn）是植物必需元素，为了探究叶面喷施纳米MnO2对水稻富集Cd的影响机制，本研究在酸性Cd污染土壤上进行田间小区试验，在水稻抽穗早期叶面喷施0.1%、0.3%和0.5%的纳米MnO2溶液.结果表明与对照组相比，叶面喷施不同浓度的纳米MnO2可以有效降低水稻叶、壳和糙米中的Cd含量，增加所有部位的Mn含量，但对水稻的产量影响不大.叶面喷施纳米MnO2后，提高了叶片光合作用效果，抑制了叶片脂质过氧化，增加了氧化应激酶的含量，从而缓解Cd对水稻的胁迫.此外，叶面喷施纳米MnO2增加了水稻根表铁锰胶膜的含量，强化了铁锰胶膜对Cd的吸附/共沉淀作用，从而限制水稻根系吸收Cd.因此，在水稻抽穗早期叶面喷施纳米MnO2是一种增加糙米中Mn含量和减少Cd含量的有效措施. |
| 英文摘要 |
| Cadmium (Cd) is easily enriched in rice, resulting in an excessive Cd content in the grain, which seriously threatens human health. Manganese (Mn) is an essential element of plants. In a field experiment on Cd-contaminated acid soils, we investigated the effectiveness and mechanism of Mn in minimizing Cd accumulation in rice via foliar spraying using 0.1%, 0.3%, and 0.5% nano-MnO2 solutions at an early stage of heading. Compared with a control treatment, foliar spraying effectively reduced the Cd content of rice leaves, husks, and brown rice; increased the Mn content of all rice organs; but had no effect on rice yield. Foliar application of nano-MnO2 alleviated the plant stress induced by Cd by improving leaf photosynthesis, inhibiting lipid peroxidation, and increasing the content of the oxidative stress protein kinase. In addition, foliar application of nano-MnO2 limited the absorption of Cd by roots by increasing the content of iron-manganese plaque on the surfaces of rice roots and strengthening its adsorption/co-precipitation of Cd. Therefore, foliar application of nano-MnO2 during the early stages of rice heading is an effective measure to increase the Mn content and reduce the Cd content of brown rice. |
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