铬(Cr6+)对水花生愈伤组织的毒害效应

研究了不同浓度的Cr6+(0、0.1、0.2、0.5、1.5 mmolL-1)对水花生愈伤组织内几种代表性生理生化指标的胁迫效应,并对其进行电镜观察.结果表明:(1)随着Cr6+浓度的增加,总叶绿素、叶绿素a/b和可溶性蛋白含量,均呈先升后降趋势.(2)超氧阴离子(O 2)和过氧化氢(H2O2)含量在0.1 mmo...

Toxic of chromium(Cr6+)on the callus of Alternanthera philoxeroides

This study focused on changes of several representative physiological characteristics and ultrastructure in the callus of Alternanthera philoxeroides under different concentrations of Cr6+ stress(0,0.1,0.2,0.5,1.5 mmol·L-1).The results showed that with the increasing of Cr6+,(1)total chlorophyll(Chl),chlorophyll a/b(Chl a/b)and total soluble protein contents showed the same trend,which increased firstly and then decreased.(2)Superoxide anion(O-2·)and hydrogen peroxide(H2O2)content irritably increased compared to the control group,then decreased,however,it's always higher than that of control.(3)The soluble sugar content enhanced with the increasing of Cr6+ concentration.(4)Activities of supeoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)and ASA and GSH contents all increased first and then decreased.(5)Transmission electron microscope observation indicated that Cr6+ also imposed injury action on ultrastructure of callus cells:thylakoid twisted,chloroplast envelope broke and large starch grain formed,mitochondria disappeared and formed vacuolization,nucleolus lost and chromatin condensed in nucleus,and endoplasmic reticulum vanished by means of vesiculation.The conclusion could be reached that toxic effects of Cr6+ on callus resulted in disorder of physiological and biochemical metabolism and destruction of ultrastructure of callus cells.