氧化石墨烯对玉米幼苗生长及生理特征的影响

Effect of graphene oxide on seedling growth and physiological characteristics of maize

为探究氧化石墨烯(GO)对玉米幼苗生长及生理特征的影响,采用水培试验,使用不同浓度的GO处理玉米幼苗,测定了玉米幼苗的生长状态、根部形态、叶绿素含量、抗氧化酶活性及丙二醛(MDA)含量等指标。结果表明:在培养9 d后,GO处理对玉米幼苗的生长具有一定的抑制作用,且随着GO浓度的增加抑制作用逐渐增强,在200 mg·L^(-1)浓度时,主根根长与根冠比分别较对照(不添加GO)降低了79.8%和65.9%;随着GO处理浓度的增加,叶绿素含量呈现先上升后下降的趋势;GO处理的玉米幼苗根系组织中超氧化物歧化酶(SOD)和过氧化物酶(POD)活性并未出现明显变化,过氧化氢酶(CAT)活性与MDA含量随着GO浓度的增加而升高,在200 mg·L^(-1)浓度时,分别较对照升高了187.5%和335.6%。研究表明,GO处理对玉米幼苗产生一定程度的氧化胁迫,影响各项生理生化指标,进而促使根部形态变化并抑制玉米幼苗的生长发育,尤其是在GO高浓度时,抑制效应更加显著。

To investigate the effects of graphene oxide(GO)on the growth and physiological characteristics of maize,maize seedlings were treated with different concentrations of GO in hydroponic experiments.The growth status,root morphology,chlorophyll content,antioxidant enzyme activity,and malondialdehyde(MDA)content of the maize seedlings were determined.After 9 days of culture,GO treatment significantly inhibited the growth of maize seedlings in a concentration-dependent manner.When the GO concentration was 200 mg·L^(-1),the main root length and the root/shoot ratio decreased by 79.8%and 65.9%,respectively.With increasing GO concentration,chlorophyll content increased initially and then decreased.No significant differences were observed for superoxide-dismutase or peroxidase activities,whereas catalase(CAT)activity and MDA content increased with increasing GO concentration.When the GO concentration was 200 mg·L^(-1),CAT activity and MDA content increased by 187.5%and 335.6%,respectively.These results indicated that GO treatment induced a certain degree of oxidative stress on maize seedlings,which affected various physiological and biochemical indices,thus promoting root morphological changes and inhibiting their growth and development.This inhibitory effect was more significant at high GO concentrations.