| 超积累植物垂序商陆(Phytolacca americana L.)吸收锰机制的初步探讨 |
| 摘要点击 1854 全文点击 1320 投稿时间：2013-04-02 修订日期：2013-05-17 |
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| 中文关键词 超积累植物 垂序商陆 锰 抑制剂 吸收机制 |
| 英文关键词 hyperaccumulator Phytolacca americana L. manganese inhibitor uptake mechanism |
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| 中文摘要 |
| 垂序商陆是中国境内发现的锰超积累植物,了解其对锰的吸收特性及机制可为植物修复提供基础信息. 通过人工培养液温室培养方法,探讨了低锰浓度处理下垂序商陆吸收累积锰的特性; 采用同步辐射荧光技术(SRXRF)分析了锰在垂序商陆根横截面的分布特征; 应用能量代谢抑制剂2,4-二硝基苯酚(DNP)和矾酸钠(Na3VO4)、钙离子通道抑制剂氯化镧(LaCl3)研究了垂序商陆对锰吸收,并探讨了其吸收机制. 结果表明,低锰浓度处理下,锰超积累植物垂序商陆仍然具有较高的吸收和累积锰的能力,5 μmol·L-1低锰浓度处理下垂序商陆根、茎、叶锰含量(以干重计)仍可高达402、208、601 mg·kg-1. 锰在垂序商陆根横截面中柱含量最高,其次为表皮,皮层锰含量最少,锰从皮层进入到中柱是一个从低浓度到高浓度的过程,表明垂序商陆对锰的吸收可能存在主动运输过程. DNP和Na3VO4对垂序商陆锰吸收有一定的抑制作用,表明锰进入细胞是需要消耗能量的,进一步说明垂序商陆对锰的吸收存在主动吸收的过程. 钙离子通道抑制剂LaCl3抑制垂序商陆根对锰的吸收高达30%,表明垂序商陆对锰的吸收与钙离子通道密切相关. |
| 英文摘要 |
| Phytolacca americana L. (P. americana) is a manganese (Mn) hyperaccumulator plant discovered in southern China, and knowledge of Mn uptake characteristics and mechanisms on this plant may provide essential and critical information for phytoremediation. Synchrotron radiation X-ray fluorescence spectroscopy (SRXRF) microprobe was empolyed in this study to explore the Mn distribution in the root cross-section of P. americana, and effects of metabolic inhibitors (DNP and Na3VO4) and Ca-channel inhibitor (LaCl3) on Mn uptake of P. americana was also investigated under laboratory conditions. Results showed that P. americana has strong abilities for absorpting and accumulating Mn, and the Mn concentration in root, stem, and leaf of P. americana may reach up to 402, 208, and 601 mg·kg-1 DW, respectively, even only treated with 5 μmol·L-1 Mn. The highest Mn content can be found in the vascular bundle of root, and then the epidermis, while the lowest Mn content can be observed in the cortex. The Mn content increased when shifted from cortex to vascular bundle, indicating that there was an active transportation in Mn absorption of P. americana root, and the inhibitory effect of DNP and Na3VO4 on Mn uptake further verified the possibilities of active absorption. The Mn uptake was inhibited by 30% with LaCl3, suggesting that Mn uptake in P. americana also closely related to the Ca-channel. |
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