水溶性有机物对绿麦隆胁迫下小麦幼苗生物利用性和毒性的影响

Effects of Dissolved Organic Matter on Bioavailability and Toxicity of Chlorotoluron to Wheat

研究了在2种来源的DOM(水溶性有机物)和绿麦隆作用下,小麦幼苗在不同培养时间(4和10 d)组织累积量和抗氧化系统的响应,探讨了小麦幼苗在DOM作用下对绿麦隆胁迫的毒性响应影响及机制.结果表明:在不同的培养期内,绿麦隆均抑制了小麦幼苗的生长,而2种不同来源的DOM均缓解了绿麦隆对植株的毒性.DOM的施加使绿麦隆胁迫下小麦叶和根中的丙二醛(MDA)含量降低,同时绿麦隆诱导的超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的活力也有所降低,然而过氧化物酶(POD)和谷胱甘肽巯基转移酶(GST)的活性却有一定程度的增高.使用RT-PCR半定量分析方法对SOD和GST的酶活性变化进行了分析,以确证DOM缓解绿麦隆对小麦幼苗的毒性调节机制.

The effects and mechanism of DOM in regulating chlorotoluron（Chl）-induced toxicity to wheat seedlings were investigated based on wheat seedling growth under two DOMs extracted from sludge and straw and chlorotoluron over four and ten day periods.The results indicated that chlorotoluron inhibited wheat seedling growth for both the four and ten day incubation periods,and the two DOMs weakened this effect.Application of DOMs reduced the amount of MDA in the leaves and roots of the wheat.The activities of superoxide dismutase（SOD） and catalase（CAT） induced by chlorotoluron were also decreased by the DOMs.However,the activities of peroxidase（POD） and glutathione S-transferases（GST） were increased by the DOMs.Furthermore,RT-PCR analysis was used to test the activity change of SOD and GST,and then to confirm the mechanism of DOM on the toxicity relieving of chlorotoluron on wheat seedlings.