Mixture of Pb, Zn and Cu on root permeability and radial oxygen loss in the mangroveBruguiera gymnorrhiza
Mixture of Pb, Zn and Cu on root permeability and radial oxygen loss in the mangroveBruguiera gymnorrhiza
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铅、锌、铜混合物对红树木榄根系通透性和径向氧损失的影响
DOI：
10.1007/s10646-020-02234-z
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发表时间：
2020-08-01
期刊：
影响因子：
2.7
通讯作者：
Sun, Fun-Lin
中科院分区：
文献类型：
--
作者：
Cheng, Hao;Wang, You-Shao;Sun, Fun-Lin
采用短期盆栽试验，研究了混合重金属(铜、铅、锌)对木本植物生长、径向失氧和根系解剖的影响。并对细胞色素P450基因BgC4H在根系木质化过程中的可能作用进行了讨论。铜、铅和锌的混合暴露直接减少了根表面的O2渗漏。重金属抑制的ROL下降主要归因于根系解剖特征的变化，如根孔隙度的减少和外胚层木质化的增加。发现BgC4H在0.5天的金属暴露后上调，并在3天的金属暴露中与对照根相比保持更高的转录水平。此外，光合作用的抑制也可能导致可输送到地下根的氧气减少。综上所述，红树植物木本植物通过形成木质化的、不透水的外皮层对外部混合金属污染物产生反应，而铜、铅、锌的混合诱导的这种根屏障似乎是阻止金属离子进入根的适应性反应。
A short term pot trail was employed to evaluate the exposure of mixed heavy metals (Cu, Pb and Zn) on growth, radial oxygen loss (ROL) and root anatomy in Bruguiera gymnorrhiza. The possible function of BgC4H, a cytochrome P450 gene, on root lignification was also discussed. The exposures of mixed Cu, Pb and Zn directly reduce O2 leakage at root surface. The reduced ROL inhibited by heavy metals was mainly ascribed by the changes in root anatomical features, such as decreased root porosity together with increased lignification within the exodermis. BgC4H was found to be up-regulated after 0.5-day metal exposure, and remained higher transcript levels within 3-day metal exposure when compared to control roots. Besides, the inhibited photosynthesis may also result in less oxygen can be transported to the underground roots. In summary, the mangrove B. gymnorrhiza appeared to react to external mixed metal contaminants by developing a lignified and impermeable exodermis, and such a root barrier induced by mixed Cu, Pb and Zn appeared to be an adaptive response to block metal ions enters into the roots.