Metal (Pb, Zn and Cu) uptake and tolerance by mangroves in relation to root anatomy and lignification/suberization
Metal (Pb, Zn and Cu) uptake and tolerance by mangroves in relation to root anatomy and lignification/suberization
复制标题
红树林对金属（Pb、Zn 和 Cu）的吸收和耐受性与根部解剖结构和木质化/木栓化的关系
DOI：
10.1093/treephys/tpu042
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发表时间：
2014-06-01
期刊：
影响因子：
4
通讯作者：
Wang, You-Shao
中科院分区：
文献类型：
--
作者：
Cheng, Hao;Jiang, Zhao-Yu;Wang, You-Shao
Metal pollution has been widely reported in mangrove wetlands; however, the mechanisms involved in metal detoxification by mangroves are still poorly understood. This study aimed to investigate the possible function of root anatomy and lignification/suberization on metal uptake and tolerance in seedlings of six species of mangroves. The results revealed that the three rhizophoraceous species (Bruguiera gymnorrhiza (L.) Poir, Kandelia obovata Sheue, Liu & Yong and Rhizophora stylosa Griff) consistently exhibited higher metal tolerances than the three pioneer species (Aegiceras corniculatum (Linn.) Blanco, Acanthus ilicifolius L. and Avicennia marina (Forsk.) Viern.). Moreover, metal-tolerant species often exhibited a thick exodermis with high lignification and suberization. The tolerance indices of the mangroves were found to be positively correlated with the amounts of lignin and suberin deposition within the exodermal cell walls. The observed metal uptake by the excised roots further illustrated that a lignified/suberized exodermis directly delayed the entry of metals into the roots, and thereby contributed to a higher tolerance to heavy metals. In summary, the present study proposes a barrier property of the lignified/suberized exodermis in dealing with the stresses of heavy metals, such that the mangroves which possessed more extensive lignification/suberization within the exodermis appeared to exhibit higher metal tolerance.
