Enhanced root-to-shoot translocation of cadmium in the hyperaccumulating ecotype of Sedum alfredii.
Enhanced root-to-shoot translocation of cadmium in the hyperaccumulating ecotype of Sedum alfredii.
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景天超富集生态型中镉从根到茎的易位增强
DOI：
10.1093/jxb/ern174
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发表时间：
2008
影响因子：
6.9
通讯作者：
He, Zhen-li
中科院分区：
文献类型：
--
作者：
Lu, Ling-li;Tian, Sheng-ke;Yang, Xiao-e;Wang, Xiao-chang;Brown, Patrick;Li, Ting-qiang;He, Zhen-li
东南景天（Crasulaceae）是目前已知的唯一一种非芸苔属植物的Cd超积累植物，其Cd超积累的机制尚不清楚。在这里，放射性技术，代谢抑制剂和荧光成像的组合被用来对比镉的吸收和转运之间的超积累生态型（HE）和非超积累生态型（NHE）的S。alfredii。109 Cd流入根系的Km在两种生态型中相似，而Vmax在HE中高2倍。在HE中观察到低温或代谢抑制剂对Cd吸收的显著抑制，而在NHE中的效果不太明显。高钙处理也显著降低了两种生态型植物根系109 Cd的流入量。HE处理的109 Cd向地上部的转运速率是NHE处理的10倍以上，地上部积累的109 Cd浓度显著高于NHE处理。此外，代谢抑制剂羰基氰间氯苯腙（CCCP）导致显着减少镉含量的芽的HE，并在根的NHE。Cd在HE中优先分布于根柱，而在NHE中没有分布，HE木质部汁液中Cd浓度是NHE的3-5倍。这些结果表明，Cd超积累植物HE S的根向地上部的转运速率显著提高，而不是根系吸收速率的差异，这可能是木质部负荷增加的结果。alfredii。
Sedum alfredii (Crasulaceae) is the only known Cd-hyperaccumulating species that are not in the Brassica family; the mechanism of Cd hyperaccumulation in this plant is, however, little understood. Here, a combination of radioactive techniques, metabolic inhibitors, and fluorescence imaging was used to contrast Cd uptake and translocation between a hyperaccumulating ecotype (HE) and a non-hyperaccumulating ecotype (NHE) of S. alfredii. The Km of 109Cd influx into roots was similar in both ecotypes, while the Vmax was 2-fold higher in the HE. Significant inhibition of Cd uptake by low temperature or metabolic inhibitors was observed in the HE, whereas the effect was less pronounced in the NHE. 109Cd influx into roots was also significantly decreased by high Ca in both ecotypes. The rate of root-to-shoot translocation of 109Cd in the HE was >10 times higher when compared with the NHE, and shoots of the HE accumulated dramatically higher 109Cd concentrations those of the NHE. The addition of the metabolic inhibitor carbonyl cyanide m-chlorophenylhydrazone (CCCP) resulted in a significant reduction in Cd contents in the shoots of the HE, and in the roots of the NHE. Cd was distributed preferentially to the root cylinder of the HE but not the NHE, and there was a 3–5 times higher Cd concentration in xylem sap of the HE in contrast to the NHE. These results illustrate that a greatly enhanced rate of root-to-shoot translocation, possibly as a result of enhanced xylem loading, rather than differences in the rate of root uptake, was the pivotal process expressed in the Cd hyperaccumulator HE S. alfredii.
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影响因子：
7.4
作者：
Hart, JJ;Welch, RM;Kochian, LV
通讯作者：
Kochian, LV
影响因子：
6.9
作者：
Lasat, MM;Pence, NS;Kochian, LV
通讯作者：
Kochian, LV
影响因子：
7.4
作者：
Lasat, MM;Baker, AJM;Kochian, LV
通讯作者：
Kochian, LV
影响因子：
4.3
作者：
Lindberg, S;Landberg, T;Greger, M
通讯作者：
Greger, M
影响因子：
4.9
作者：
Robinson, BH;Leblanc, M;Gregg, PEH
通讯作者：
Gregg, PEH