摘要
铅是一种毒性强的重金属元素,一旦进入环境将很难修复,进而通过食物链危及人类健康。傅里叶变换红外光谱法(FTIR)具有准确度好、简便快捷、分辨率高的特点,是一种探讨植物重金属耐性机理的可行方法。紫茉莉是一种生长快的多年生草本植物,有应用于铅污染土壤植物稳定的前景。通过温室培养,研究不同铅处理条件下(0,50,100,200,500,1000μmol/L),紫茉莉不同组织器官(根、茎、叶)的傅立叶红外光谱(FTIR)图谱变化,结果发现,生长介质铅处理浓度低于500μmol/L时对紫茉莉的生长基本没有影响,当Pb处理浓度达到1000μmol/L时,生物量略显降低,但是各处理浓度间生物量差异性不显著。紫茉莉根组织在3420,2920,1610,1060 cm-1等处峰高先上升后下降,反映蛋白质、氨基酸、糖类、羧酸等物质在低铅处理条件下往往作为渗透性调节物质出现,有机物含量升高,但随着铅含量的升高,其合成和运输受限,有机物含量逐渐下降;茎组织在2920,1630,1380,1060 cm-1等处峰高无明显变化;叶组织在1650 cm-1处峰高随铅处理浓度升高而升高,这可能与紫茉莉叶中蛋白质和氨基酸等物质含量升高有关。这表明,紫茉莉通过根系有机物含量的变化,将植物吸收的Pb大部分积累在根部,阻止Pb向地上部分运输,有效的保护了植物地上部分。
Industries such as metal smelters,refineries,and mining operations have been indicated as major sources of metals release into the environment.Pb is a highly toxic and cumulative poisonous element.Similar to other metals,once released into the environment,it is difficult to recover and can adversely affect human health.Mirabilis jalapa Linn.is a fast growing plant,with the proven ability to stabilize Pb from contaminated soils.Fourier transform infrared（FTIR） spectrometry,which is accurate,simple and efficient,with high resolution,was used to investigate the physiological changes in chemical composition of M.jalapa L.exposed to six different levels of Pb in solution（0,50,100,200,500,1000μmol/L）.At Pb concentration below 500 μmol/L,M.jalapa could grow normally,without any symptoms of Pb toxicity,although with a lower biomass at 1000 μmol/LPb than the control samples.Using the roots,stems and leaves of M.jalapa,absorption bands corresponding to carbohydrates,ester and proteins varied differently.The absorbance of the dominating bands near 3420,2920,1610,1060 cm-1 which corresponded to organic acids,carbohydrate,protein and amino acids elevated initially and then decreased in root tissues,but no obvious changes in leaves and stems were noted.All these results suggested that Mirabilis jalapa inhibited the transportation of Pb from roots to shoots.Hence,it is practical to apply FTIR to explore the physiological mechanism of lead tolerance by higher plants.
出处
《生态学报》
CAS
CSCD
北大核心
2011年第20期6143-6148,共6页
Acta Ecologica Sinica
基金
国家公益性(环保)行业科研项目(200909065
201109056)
国家自然科学基金项目(40771181)
