Accumulation and toxic effects of chromium and zinc in Iris pseudacorus L.
Accumulation and toxic effects of chromium and zinc in Iris pseudacorus L.
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DOI：
10.1007/s11738-012-0956-4
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发表时间：
2012-05-01
影响因子：
2.6
通讯作者：
Bort, J.
中科院分区：
文献类型：
--
作者：
Caldelas, C.;Araus, J. L.;Bort, J.
本研究旨在研究极具植物修复潜力的观赏植物假独角草对铬、锌的耐受和积累能力。植株在含有0、10、50、100和200mgml(-1)浓度的氯化锌或氯化铬中心点6H(2)O的营养液中生长5周，全部存活并继续生长。铬和锌在所有植物组织中的积累量随着供给量的增加而增加，根中铬和锌的积累量分别达到59.97 mg和25.64 mg。叶片保留了相当数量的锌(14.2 mg)。铬和锌的生长抑制率分别达到65%和31%(干重)。根：当CrCl3浓度为100mgml(-1)时，地上部干物质分配比(R/S)提高80%。矿物质含量变化最明显的是根部，两种金属元素都降低了铝、钙、镁、锰和S的含量，增加了磷的浓度。对叶片叶绿素荧光动力学(F(V)/F(M)和I折断垂直杆(PSII))和光合色素含量均无影响，说明光合作用的光期没有受到影响。碳同位素组成(增量C-13)仅略重，说明固碳减少不是生长减慢的主要原因。这是由于受伤害的根对矿物质的吸收受到限制，对碳水化合物的需求增加。生物量分配到根茎(Cr)或根部(Zn)，通过限制蒸腾作用，增加金属储存组织和表面对水分和阳离子的吸收，有助于提高对重金属的耐受性。本种是铬根滤和锌植物提取的很好候选者。
The aim of the present study was to examine the ability of I. pseudacorus L., an ornamental macrophyte of great potential for phytoremediation, to tolerate and accumulate Cr and Zn. Plants were grown in nutritive solution with ZnCl2 or CrCl3 center dot 6H(2)O at 0, 10, 50, 100, and 200 mu g ml(-1) for 5 weeks; all survived and continued growing. The accumulation of Cr and Zn increased with increasing supply in all plant tissues, to reach 59.97 mg Cr and 25.64 mg Zn in roots. Leaves retained a remarkable amount of Zn (14.2 mg). Growth inhibition reached 65% and 31% (dry weight) in response to Cr and Zn, respectively. The root:shoot dry matter partitioning (R/S) increased 80% at 100 mu g ml(-1) CrCl3. The most marked alterations in mineral content were in roots, where both metals decreased Al, Ca, Mg, Mn and S, and increased P concentration. No effect was noted on either leaf chlorophyll fluorescence kinetics (F (v) /F (m) and I broken vertical bar(PSII)), or photosynthetic pigment content, signifying that the light phase of photosynthesis was not impaired. Carbon isotope composition (delta C-13) was only slightly heavier, indicating that the reduction of carbon fixation was not the main cause for growth decrease. This was attributed to the restricted mineral uptake and to the increased demand of carbohydrates of damaged roots. Biomass allocation to rhizomes (Cr) or roots (Zn) contributes to heavy metal tolerance by limiting transpiration and increasing metal-storing tissues and the surface for water and cation uptake. This species is a good candidate for Cr rhizofiltration and Zn phytoextraction.