姜花在Cu胁迫下的耐性机理研究

Tolerance Mechanism of Hedychium coronarium Under Copper Stress

采用模拟湿地盆栽试验,研究了姜花在Cu胁迫下的积累、分布、化学形态和富集能力。结果表明:(1)姜花对Cu的积累能力随Cu处理浓度的增加而增大,但各部位对Cu的积累具有明显的差异性。当Cu处理浓度≤150mg·kg-1时,其积累能力表现为根>叶>茎;当Cu处理浓度≥200mg·kg-1时,其积累能力表现为叶>根>茎。(2)Cu在姜花叶片细胞中的分布具有选择性,其主要分布位点为细胞可溶性部分和细胞壁部分,而在细胞器中Cu的含量较低。(3)Cu在姜花根、茎和叶中赋存的化学形态有明显差异。在根部,Cu的化学形态主要以乙醇提取态和水提取态为主;在茎部,Cu均以氯化钠提取态为主;而叶部Cu主要以活性较低的氯化钠提取态、醋酸提取态和盐酸提取态存在。(4)姜花对Cu具有一定的富集能力,但富集能力不强,当Cu浓度达到400mg·kg-1以上时,姜花植株便出现了较明显的毒害症状并随之死亡,因而姜花尚未达到超富集植物的标准。可见,姜花在Cu胁迫下具有一定的耐受性,分布选择性和富集能力,将其运用于湿地Cu污染修复中,将极大地缓解重金属Cu污染给环境带来的压力。

Uptake and accumulation of copper in Hedychium coronarium（ HC ）, the subcellular distribution of copper in leaf and chemical form of copper in plants under copper stress were investigated in a pot culture of simulated wetland. The results showed that the accumulation of copper in HC increased with the increase of the concentration of copper. When the concentration of copper was less than 150 mg·kg^-1, the accumulation of copper in the plant was found in the order of root〉leave〉stem. While it was in the order of leave〉root〉stem when the concen- tration of copper was no less than 200 mg·kg^-1. In all treatments, the copper in leaf was mainly on cell wall and in soluble fraction, while relatively lower in cell organelle. The copper in the root was predominated with Ethanol- and water-extractable forms, while NaCl-extractable form was dominant in the stem. Whereas NaCl-, HAC- and HCl-extractable forms in the leaf, which were less active, were dominant. In addition, HC had certain concentrating capability, yet the ability was not strong .When the concentration of copper was no less than 400 mg·kg^-1, the plants suffered from physiological hurt and death quickly, which showed that HC was not satisfied with the standard of copper hyper- accumulation plant. It came to the conclusions that HC had certain tolerance, distributing selectivity and concentrating capability under copper stress, use of which to remedy copper -polluted wetland would relieve the pressure from copper pollution.