| 两种不同镉富集能力油菜品种耐性机制 |
| 摘要点击 1601 全文点击 654 投稿时间：2019-06-23 修订日期：2019-09-23 |
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| 中文关键词 油菜 镉 耐性 亚细胞 吸收 |
| 英文关键词 Brassica napus L. cadmium(Cd) tolerance subcellular adsorption |
| 作者 | 单位 | E-mail | | 卞建林 | 首都师范大学资源环境与旅游学院, 北京 100048 | bianjlwj@163.com | | 郭俊娒 | 中国科学院地理科学与资源研究所环境修复中心, 北京 100101
中国科学院大学, 北京 100049 | | | 王学东 | 首都师范大学资源环境与旅游学院, 北京 100048 | | | 杨俊兴 | 中国科学院地理科学与资源研究所环境修复中心, 北京 100101
中国科学院大学, 北京 100049 | yangajx@126.com | | 杨军 | 中国科学院地理科学与资源研究所环境修复中心, 北京 100101
中国科学院大学, 北京 100049 | | | 陈同斌 | 中国科学院地理科学与资源研究所环境修复中心, 北京 100101
中国科学院大学, 北京 100049 | | | 曹柳 | 河南省土壤污染监测与修复重点实验室, 济源 459000 | | | 成永霞 | 河南省土壤污染监测与修复重点实验室, 济源 459000 | | | 任战红 | 河南省土壤污染监测与修复重点实验室, 济源 459000 | | | 王杰 | 中国农业科学院农业资源与农业区划研究所, 北京 100081 | | | 周小勇 | 北京瑞美德环境修复有限公司, 北京 100015 | |
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| 中文摘要 |
| 利用水培试验研究了不同浓度镉（cadmium，Cd）胁迫条件下（0、2和5 mg·L-1）两种Cd富集能力油菜品种[秦油1号（QY-1）和三月黄（SYH）]生长状况与Cd富集特征的差异，并从Cd亚细胞区隔化和抗氧化酶活性等角度探索了两种油菜Cd富集能力的差异机制，并通过田间试验进行验证.结果表明，水培条件下，这两种油菜在Cd胁迫下生长均未受到明显的抑制.在低浓度Cd（2 mg·L-1）处理下，两种油菜地上部Cd含量无显著差异，在高浓度Cd（5 mg·L-1）胁迫下SYH的地上部和根部Cd含量均显著高于QY-1，分别提高32.05%和99.57%，同时其根部生物富集系数（BCF）也较QY-1显著提高.对两种油菜叶片中Cd亚细胞区隔化研究结果表明，随着Cd处理浓度的增加，QY-1和SYH叶片中Cd在热稳定蛋白和镉富集颗粒组分的分布分别提高了143.69%、118.91%和63.34%、118.91%，由此可见将Cd区隔在热稳定蛋白和镉富集颗粒体等重金属解毒组分是油菜在亚细胞水平上的重要解毒机制.同时，高浓度Cd胁迫下SYH叶中Cd在细胞碎屑组分的含量达QY-1的4.41倍，可知Cd在细胞碎屑组分中的分布是导致两种油菜Cd富集能力差异的重要机制.结合对两种油菜抗氧化酶活性研究结果，发现抗氧化酶系统可能是QY-1应对高浓度Cd胁迫的重要解毒机制，而SYH则更多地通过将Cd区隔在金属低活性的亚细胞组分来减轻其毒性.田间试验结果验证表明，SYH地上部和地下部Cd含量均显著高于QY-1，分别是QY-1的2.34和1.43倍.综上所述，SYH具有更高的Cd提取量和富集能力，具有应用于中轻度Cd污染农田修复的潜力. |
| 英文摘要 |
| A hydroponic experiment was conducted to explore the differences in growth status and Cd accumulation characteristics of two Brassica napus L. cultivars (QY-1 and SYH) under different concentrations of cadmium (Cd) stress (0, 2, and 5 mg·L-1). The Cd subcellular compartmentalization and antioxidant enzyme activities were determined to elucidate the intrinsic mechanism of the differences in the Cd accumulation capacity between the two cultivars of Brassica napus L. Furthermore, field trials were conducted to further verify the differences in phytoremediation of the two cultivars. Results show that neither of the cultivars exhibited obvious growth inhibition under Cd stress. Under the 2 mg·L-1 Cd condition, there were no significant differences in shoot Cd concentrations between the two cultivars. Under 5 mg·L-1 Cd condition, however, the Cd concentrations in both shoot and root of SYH were significantly higher than that of QY-1, which increased by 32.05% and 99.57%, respectively. In addition, the bioconcentration factor (BCF) of the root in SYH is significantly higher than that of QY-1. The subcellular Cd distribution in leaves of the two cultivars of Brassica napus L. showed that, with an increase of Cd stress, Cd concentrations of heat stable protein (HSP) and metal-rich granule (MRG) fractions in leaves significantly increased by 143.69% and 118.91% for QY-1, and by 63.34% and 118.91% for SYH. Thus, the segregation of Cd in HSP and MRG, which was reported to be biological detoxified metal fractions (BDM), might play an important role in the detoxification of Brassica napus L. at a subcellular level under Cd stress. Moreover, the distribution of Cd in the cellular debris fraction might be another important factor contributing to the differences in Cd accumulation of the two Brassica napus L. cultivars, which was 4.41 times higher in SYH than in QY-1 under Cd stress. The results of the antioxidant enzyme activities of two Brassica napus L. cultivars showed that, under the 5 mg·L-1 Cd condition, the antioxidant enzyme system may represent an important detoxification mechanism for QY-1 to cope with stress induced by high concentrations of Cd, while SYH is more effective in reducing the toxicity of Cd by separation of Cd into BDM fractions. The results of the field trial confirmed that the Cd concentrations in the above- and underground parts of SYH were 2.34 and 1.43 times higher than in QY-1, respectively. Therefore, SYH possess a higher Cd phytoextraction capacity than QY-1, and might be a good candidate for the remediation of moderate and mildly Cd-contaminated farmland. |
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