钼缓解烟草镉毒害的生理效应及其机制  

Physiological effects and mechanisms of molybdenum on alleviating cadmium toxicity in tobacco

作　　者：毕浩东 牛慧伟 贾玮 刘晶晶 宋绍森 黄五星[1] 韩丹[1] 许自成[1] 许嘉阳 BI Haodong;NIU Huiwei;JIA Wei;LIU Jingjing;SONG Shaosen;HUANG Wuxing;HAN Dan;XU Zicheng;XU Jiayang(College of Tobacco,Henan Agricultural University,Zhengzhou 450046,China;Employee Training College of China National Tobacco Corporation,Zhengzhou 450008,China;College of Resources and Environment,Henan Agricultural University,Zhengzhou 450046,China)

机构地区：[1]河南农业大学烟草学院,郑州450046 [2]中国烟草总公司职工进修学院,郑州450008 [3]河南农业大学资源与环境学院,郑州450046

出　　处：《农业环境科学学报》2024年第4期799-809,共11页Journal of Agro-Environment Science

基　　金：河南省自然科学基金青年基金项目(222300420176);河南农业大学青年英才启动基金项目(30500999)。

摘　　要：为探究施钼对镉胁迫下烟草幼苗生理特征的缓解效果,本研究以烟草品种K326为供试作物,采集镉污染农田土壤开展盆栽实验,设置0、0.25、0.5 mg·kg^(-1)和1 mg·kg^(-1)四种钼梯度,研究钼对镉毒害下烟草幼苗外观表征、酶活性、镉积累、光合作用和抗氧化能力等生理特征的影响。结果表明,施钼改善了镉毒害下烟苗长势矮小、叶片失绿的情况,并促进了根系的生长,其中以0.5 mg·kg^(-1)的浓度处理效果最好。相较于未施钼处理,施用0.5 mg·kg^(-1)的钼促进了土壤酶的活性,分别降低了烟苗叶片和根系中17.39%和40.00%的镉含量,促进了钼的吸收;0.5 mg·kg^(-1)的钼能显著减少烟叶中活性氧等物质的积累并提高烟株的防御酶活性和抗逆激素的含量,0.25、0.5、1 mg·kg^(-1)钼处理的总抗氧化能力分别为未施钼处理的1.17、1.20倍和1.09倍。此外,施钼增强了镉胁迫下烟草的光合作用和钼酶活性,对镉胁迫下烟草的生理代谢发挥了重要的调节作用。研究表明,施用0.5 mg·kg^(-1)的钼对镉胁迫下烟草幼苗的生理特征有更好的缓解效果。This study used tobacco variety K326 as the test crop.Cadmium-contaminated farmland soil was collected for pot experiments to investigate the alleviating effect of molybdenum application on the physiological characteristics of tobacco seedlings under cadmium stress.Four molybdenum gradients of 0,0.25,0.5,and 1 mg·kg^(-1) were set up to study the effects of molybdenum on the physiological characteristics of tobacco seedlings under cadmium toxicity,including appearance characterization,enzyme activity,cadmium accumulation,photosynthesis,and antioxidant capacity.The results showed that molybdenum application improved the growth of tobacco seedlings that show signs of stunted growth and leaf chlorosis under cadmium toxicity.It also promoted root growth,with the best effect observed at a concentration of 0.5 mg·kg^(-1).Compared with the untreated treatment,the application of 0.5 mg·kg^(-1) of molybdenum promoted the activity of soil enzymes,reduced the cadmium content in tobacco leaves and roots by 17.39%and 40.00%,respectively,and promoted the absorption of molybdenum;0.5 mg·kg^(-1) of molybdenum could significantly reduce the accumulation of reactive oxygen species and other substances in tobacco leaves,and increase the activity of defense enzymes and the content of stress hormones in tobacco plants.The total antioxidant capacity of 0.25,0.5,and 1 mg·kg^(-1) of molybdenum treatment was 1.17,1.20,and 1.09 times that of the untreated treatment,respectively.In addition,molybdenum application enhanced the photosynthesis and molybdenum enzyme activity of tobacco under cadmium stress,playing an important regulatory role in the physiological metabolism of tobacco under cadmium stress.This study has shown that applying 0.5 mg·kg^(-1) of molybdenum has a higher alleviating effect on the physiological characteristics of tobacco seedlings under cadmium stress.

关 键 词：烟草 镉胁迫 钼 光合作用 抗氧化系统 酶活性 激素含量 元素积累 

分 类 号：X173[环境科学与工程—环境科学]