摘要
通过盆栽试验,研究了不同浓度(0、1、10、50、100、200 mg·kg^(-1))镉处理下,海雀稗地上部与地下部的生物量受镉胁迫的影响及其体内镉的富集特征,进一步分析低镉处理(1 mg·kg^(-1))和高镉处理(50 mg·kg^(-1))镉在海雀稗根、茎、叶中的化学形态及根、叶中镉的亚细胞分布特征.结果表明,镉浓度≤50 mg·kg^(-1),海雀稗地上部、地下部生物量和耐性系数都未显著下降,海雀稗根部对镉的积累远大于地上部分;海雀稗根系细胞壁中镉含量分配比例>50%,其次为可溶部分,高镉处理中细胞壁、可溶部分中镉的分配比例比低镉处理增加6.14%、0.32%,细胞膜部分和原生质体部分镉分配比例下降;海雀稗镉形态主要为氯化钠、醋酸提取态,高镉处理降低了毒性较高的水提取态和乙醇提取态的比例总和,根中氯化钠和盐酸提取态,茎、叶中醋酸提取态、氯化钠提取态增加.研究表明,海雀稗中毒性较低、活性较弱的盐酸提取态、醋酸提取态和氯化钠提取态Cd分配比例增加,根中细胞壁固持和液泡区隔化可能是海雀稗应对镉胁迫的重要耐性机制.
A pot experiment was conducted to investigate the effects of stress reponses of Cd and accumulation to Cd for the biomass in the root and leaf of Paspalum vaginatum Sw. with different Cd treatments（0、1、10、50、100、200 mg·kg^-1）. Further analysis was conducted for the chemical forms of Cd in the root, stem and leaf of Paspalum vaginatum Sw., and the subcellular distribution of Cd in root and leaf with two different levels of Cd treatment. The results showed that the biomass and tolerance index of the root and leaf in Paspalum vaginatum Sw. did not reduce significantly when Cd concentration in solution was below 50 mg·kg^-1. Most of the accumulated Cd was enriched in the cell wall and soluble fraction. The proportion of Cd located in cell wall is above 50% with the treatment of 50 mg·kg^-1. The proportion of Cd in cell wall of root, soluble fraction and cell wall of leaf was increased and the proportion of Cd in cytomembrane of root and leaf was reduced. The chemical forms. were FNaCl and FHAC. The Cd accumulation percentages in FNaCl and HAC extractable fractions decreased with the treatment of 50 mg·kg^-1, whereas FNaCl and HCl in root and HAC and FNaCl in leaf were increased. It indicated that, the Cd accumulation percentages in FHCl, HAC and FNaCl extractable fractions increased. Therefore, cell wall binding of root and vacuolar compartmentalization were supposed to be the main tolerance mechanisms to Cd for Paspalum vaginatum Sw.. with Cd stress.
出处
《环境化学》
CAS
CSCD
北大核心
2016年第2期330-336,共7页
Environmental Chemistry
基金
中央公益性科研院所基本科研业务专项基金(ITBB2015ZD03
1630052015038)
海南省重大科技专项(ZDZX2013023-1)资助~~
关键词
海雀稗
镉胁迫
化学形态
亚细胞分布
Paspalum vaginatum Sw, Cd, chemical form, subcellular distribution.
