Phosphate application enhances the resistance of arbuscular mycorrhizae in clover plants to cadmium via polyphosphate accumulation in fungal hyphae
Phosphate application enhances the resistance of arbuscular mycorrhizae in clover plants to cadmium via polyphosphate accumulation in fungal hyphae
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DOI：
10.1016/j.envexpbot.2013.11.007
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发表时间：
2014-12
影响因子：
5.7
通讯作者：
Q. Yao;Rui-Heng Yang;Liangkun Long;Honghui Zhu
中科院分区：
文献类型：
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作者：
Q. Yao;Rui-Heng Yang;Liangkun Long;Honghui Zhu
磷（P）施用和丛枝菌根（AM）真菌接种均可增强植物对镉毒性的抵抗力，但它们的相互作用和潜在机制仍不清楚。本研究的目的是研究施磷对AM抗Cd的影响并揭示相应的机制。我们设计了一个隔室系统来将不规则根噬菌的根外菌丝（EH）与三叶草（Trifolium ripenseL.）的根分离。 EH 中应用了不同含量的磷和镉 (Cd)。监测P和Cd的含量和吸收。对 EH 中的聚磷酸盐 (polyP) 积累进行了定量。使用荧光染色可视化 PolyP 和 Cd 的定位。结果表明，Cd 大大降低了 EH 生物量和 PolyP 积累，而 P 则增加了 PolyP 积累。 EH 中 PolyP 的积累增强了 AM 对 Cd 的抗性，同时也减少了植物对 Cd 的吸收。荧光图像表明 Cd 信号和 PolyP 信号重叠。这些数据表明，施磷可以通过多聚磷螯合增强AM对Cd的抗性，这代表了AM菌丝对Cd解毒除了菌丝吸收之外的另一种机制。
Both phosphorus (P) application and arbuscular mycorrhizal (AM) fungal inoculation can enhance plant resistance to Cd toxicity, however, their interaction and the underlying mechanism are still unclear. The aims of this study were to investigate the effect of P application on AM resistance to Cd and to reveal the corresponding mechanism. We designed a compartmented system to separate extraradical hyphae (EH) ofRhizophagus irregularisfrom the roots of clover (Trifolium ripenseL.). EH was applied with different levels of P and cadmium (Cd). The content and uptake of P and Cd were monitored. Polyphosphate (polyP) accumulation in EH was quantified. The localization of polyP and Cd was visualized using fluorescent staining. Results indicated that Cd greatly decreased EH biomass and polyP accumulation while P increased polyP accumulation. PolyP accumulation in EH enhanced AM resistance to Cd, and also reduced Cd uptake by plants. Fluorescent images indicated the overlapping of Cd signals and polyP signals. These data suggest that P application can enhance the resistance of AM to CdviapolyP chelation, and this represents another mechanism underlying the detoxification of Cd by AM hyphae other than the absorption by hyphae.