超积累植物水蓼吸收锰的生理与分子机制  

Physiological and Molecular Mechanisms of Mn Uptake by Hyperaccumulting Plant Polygonum hydropiper (Polygonaceae)

作　　者：王华[1] 唐树梅[1] 廖香俊[2] 曹启民[3] 

机构地区：[1]海南大学农学院 [2]海南省地质勘查局,海南海口570100 [3]中山大学环境科学与工程学院,广东广州510275

出　　处：《云南植物研究》2008年第4期489-495,共7页Acta Botanica Yunnanica

基　　金：国家科技部科技基础性工作和社会公益研究专项(No.2004DIB3J073)

摘　　要：水蓼(Polygonum hydropiper)是一种新近发现的锰超积累植物。本文通过营养液模拟试验,研究了锰在水蓼细胞中的分布与化学形态特征,以及锰胁迫下水蓼的生理生化响应机制。结果表明:锰在水蓼叶片非活性代谢部分(细胞壁和液泡)的积累是其解毒耐锰的主要机制之一;水蓼叶片中的锰大部分以水溶性有机盐或草酸锰的形态存在;在锰浓度处理为8000μmol/L时,叶绿素a含量显著降低,而在其它处理条件下,叶绿素a无明显变化;在锰处理≤5000μmol/L时水蓼叶片的细胞膜还没有受到明显伤害;水蓼叶片的可溶性蛋白含量随锰处理浓度不同而变化,说明植物在代谢和结构上发生了调整;随锰处理浓度的增加,水蓼叶片SOD和POD活性提高,保护酶活性的提高又可清除活性氧自由基,这是水蓼耐高锰和累积锰的一种生理响应机制。Polygonum hydropiper was a new hyper-accumulated Mn plant. The experiments were carried out in order to find out subcellular distribution characteristics and chemical pattern of Mn in cell and the physiological and biochemical mechanisms of Polygonum hydropiper responding to Mn stress. The results indicated that the accumulation of Mn in the cell wall （accumulation rate as high as 36.34% ） and the vacuole of the leaves （accumulation rate as high as 65.64% ） might be one of the mechanisms of tolerance and hyperaccumulation of Polygonum hydropiper to Mn. Most Mn in leaves were the speciation of H2O-solubility organic salts or manganese oxalates. The content of chlorophyll a did not change under different Mn concentration treatments except that its content decreased remarkably when Mn concentration was 8 000μmol/L in solutions. The membranes were not harmed by Mn when its concentration was less than 5 000 μmol/L in solutions; Under different Mn concentrations of Mn, the content of their soluble proteins of leaves had changed at some stage. The activity of SOD and POD were gradually improved with the increasing of Mn concentration, which could eliminate activated oxygen free radical, This might be the other physiological mechanism of tolerance and hyperaccumulation of Polygonum hydropiper responding to Mn.

关 键 词：水蓼 锰 超积累 分布 形态 生理响应 

分 类 号：X173[环境科学与工程—环境科学]