硫对镉胁迫下蓖麻生理生化特性的影响  

Regulation of Exogenous Sulfur on Physiological and Biochemical Characteristics of Ricinus Communis L. under Cd Stress

作　　者：李君[1] 葛跃[1] 孙向武[1] 王明新[1] 赵兴青[1] 

机构地区：[1]常州大学环境与安全工程学院,江苏常州213164

出　　处：《常州大学学报（自然科学版）》2016年第3期48-53,共6页Journal of Changzhou University：Natural Science Edition

基　　金：江苏省高校自然科学基金项目(14KJB610001);国家自然科学基金资助项目(41302025)

摘　　要：以淄蓖麻5号为供试材料,采用营养液培养方法,研究了不同硫(S)浓度下(0、0.5、1、2mmol·L^(-1))镉(Cd)(50μmol·L^(-1))胁迫对蓖麻叶片生理特性的影响。结果表明:适度施硫降低了镉胁迫下蓖麻叶片中过氧化氢(H2O2)和丙二醛(MDA)含量,提高了叶片中关键酶的活性和抗氧化物质的含量;1mmol·L^(-1)的硫处理使镉胁迫下蓖麻叶片中的MDA和H_2O_2含量分别降低了30.43%和39.22%;镉胁迫下低浓度硫处理对蓖麻叶片超氧化物歧化酶(SOD)活性影响不明显,但高浓度硫(2mmol·L^(-1))处理明显抑制了蓖麻叶片SOD活性。当硫处理水平为0.5mmol·L^(-1)时,叶片过氧化物酶(POD)活性达到最高。之后,POD活性开始下降,说明高浓度硫处理使POD也受到伤害,进而对蓖麻叶片细胞产生毒害作用。由此可见,硫缓解镉毒害存在剂量效应关系;当硫处理浓度为2mmol·L^(-1)时,抗坏血酸(AsA)和还原型谷胱甘肽(GSH)含量均达到峰值。这表明硫显著提高了蓖麻叶片中的AsA和GSH含量,从而促进植物体内H_2O_2等活性氧的清除,缓减镉对蓖麻叶片的毒害,进而提高蓖麻对镉的耐性。可见,硫可通过调节蓖麻叶片中的抗氧化酶活性和抗氧化剂代谢来提高对镉胁迫的耐性。A hydroponic experiment was conducted to investigate physiological and biochemical indexes in leaves of Ricinus communis（Zibima 5）with Cd doses of 50μmol·L^-1 and different sulfur treatment（0,0.5,1,2mmol·L^-1）in nutrient solution.The results indicated that reasonable application of sulfur decreased the contents of peroxide（H_2O_2）and malondialdehyde（MDA）,but increased key enzymes activities and antioxidants content in leaves ofRicinus communis.Compared with the control,the contents of MDA and H_2O_2 in leaves were decreased by 30.43% and 39.22% with 1mmol·L^-1 of sulfur treatment,respectively.There was no significant effect on the activity of SOD in leaves of Ricinus communis with lower concentration of S（0.5、1mmol·L^-1）.While the activity of SOD was obviously inhibited when exposed to higher level of S（2mmol·L^-1）.The activity of POD reached the highest with 0.5mmol·L^-1 of sulfur treatment.After that,the activity of POD began to decline.The high concentrations of S did damage to POD,which was harmful the leaves of Ricinus communis.That is,there exists dose effects on alleviating toxicity of cadmium under sulfur treatment.The contents of AsA and GSH reached the peak in the 2mmol·L^-1 sulfur level,This indicated that,in presence of exogenous sulfur significantly increased the contents of AsA and GSH,so as to promote the removal of active oxygen such as H_2O_2,which helps to alleviate the toxicity of Cd.and improved the Ricinus communis on Cd tolerance.This may be one of the important reasons to alleviate the toxicity of Cd.The above conclusions provide a new insight into antioxidant enzymes activities and antioxidants metabolism involving in Cd tolerance and detoxification in Ricinus communis under the control of sulfur.

关 键 词：蓖麻 镉胁迫 硫 生理生化特征 

分 类 号：TQ316.334[化学工程—高聚物工业]