【摘要】 在一定Mn浓度梯度处理下(0,0·125,0·25,0·5,1g·kg-1),超积累植物——美洲商陆(Phyto-laccaamericana)不同组织器官的傅里叶变换红外光谱(FTIR)图谱发生了变化。其中,茎组织在3336和2916cm-1处峰高先上升后下降,反映了有机物运输受阻情况的变化,即美洲商陆在低Mn刺激下会产生大量有机物作为渗透调节物质来增强其耐Mn性,高Mn则抑制了有机物的分泌和运输;根和叶组织分别在2922和1606cm-1处表现不同变化趋势,但都反映了一个变化规律即低Mn处理下美洲商陆分泌的有机酸不断螯合Mn,随着Mn毒害的加重,其羧酸螯合力变弱;根组织1732和1026cm-1、茎组织1028cm-1、叶组织1052和967cm-1处呈现差异性变化,但都与其膜脂过氧化有关;根组织1375cm-1处峰高先上升后下降,可能与植物在细胞壁结构上增强抗逆性有一定关系,即低Mn处理下细胞壁可能通过阳离子交换能力(CEC)的提高增强了耐Mn性。以上说明,利用FTIR研究重金属超积累植物化学组分具有应用价值。更多还原

【Abstract】 A technique based on Fourier transform infrared(FTIR) spectrometry was used to detect the physiological changes in chemical composition of Phytolacca americana under a wide range of Mn2+ treatments(0,0.125,0.25,0.5 and 1 g·kg-1).Using the roots,stems and leaves of phytolacca americana,absorption bands corresponding to carbohydrates,ester and proteins varied differently.The absorption band heights at 3 000 and 2 916 cm-1 of stem tissues rose firstly and then decreased,indicating the exudation and transporting situation of organic substances which served as organic osmotic contents to enhance manganese tolerance under low treatments;Meanwhile,the band heights at 2 922 cm-1(roots) and 1 606 cm-1(leaves) which have different tendency in accordance with Mn treatments showed that the capability to chelate Mn decreased under higher manganese concentration.In addition,the changes of the bands at 1 732 and 1 026 cm-1(roots),1 028 cm-1(stems),1 052 and 967 cm-1(leaves) differed from each other,suggesting that under the conditions of severe Mn stress the ex-oxidation of membrane lipid increased;Otherwise,the band heights at 1 375 cm-1 increased firstly and then decreased,representing that the cell wall improved Mn resistance by increasing cation-exchange capacity(CEC).The result also implied that it is practical to apply FTIR to the research comparing the chemical differences of phytoaccumulators under metal treatments.更多还原