镉胁迫下外源壳聚糖对小麦幼苗生理特性、抗氧化能力及镉吸收的影响  

Effect of Exogenous Chitosan on Physiological Properties,Antioxidant Activity,andCadmium Uptake of Wheat(Triticum aestivum L.)Seedlings Under Cadmium Stress

作　　者：张静静[1] 焦秋娟 徐正阳 范丽娜 姜瑛[1] 宋佳 化党领[1] 李鸽子[2] 林迪 柳海涛 ZHANG Jing-jing;JIAO Qiu-juan;XU Zheng-yang;FAN Li-na;JIANG Ying;SONG Jia;HUA Dang-ling;LI Ge-zi;LIN Di;LIU Hai-tao(College of Resources and Environment,Henan Agricultural University,Zhengzhou 450046,China;National Engineering Research Center for Wheat,Henan Agricultural University,Zhengzhou 450046,China;College of Forestry,Henan Agricultural University,Zhengzhou 450046,China)

机构地区：[1]河南农业大学资源与环境学院,郑州450046 [2]河南农业大学国家小麦工程研究中心,郑州450046 [3]河南农业大学林学院,郑州450046

出　　处：《环境科学》2024年第6期3649-3660,共12页Environmental Science

基　　金：河南省留学人员科研择优项目(30602340);河南省科技攻关项目(222102320078);河南农业大学大学生创新训练计划项目(2022DC158)。

摘　　要：为探究壳聚糖(CTS)缓解小麦幼苗镉(Cd)毒害的机制,通过水培试验,以百农207小麦为试验材料,研究外源壳聚糖对Cd胁迫下小麦幼苗的生理特性、抗氧化能力和Cd积累的影响,并利用偏最小二乘(PLS)回归模型定量分析幼苗各理化指标与镉积累量间的关系.结果表明,相较于CK,10μmol·L^(-1)和25μmol·L^(-1)Cd胁迫显著抑制了小麦幼苗的叶绿素含量(叶绿素a、叶绿素b、类胡萝卜素和总叶绿素)、光合作用和生物量的积累,使得幼苗根系变短变粗且侧根减少,同时改变了超氧化物歧化酶(SOD)和过氧化物酶(POD)活性,增加了H_(2)O_(2)和丙二醛(MDA)的积累.镉胁迫下,外源壳聚糖使小麦幼苗茎叶和根系镉含量分别降低13.22%~21.63%和7.92%~28.32%,镉积累量分别降低5.37%~6.71%和1.91%~4.09%.不同镉水平下,外源壳聚糖使小麦根系和茎叶中H_(2)O_(2)含量显著降低了38.21%~47.46%和45.81%~55.73%,MDA含量显著降低了37.65%~48.12%和29.87%~32.51%;根系中SOD和POD含量分别提高2.78%~5.61%和13.81%~18.33%.外源壳聚糖可通过提高Cd胁迫下小麦幼苗的光合特征和抗氧化酶活性的方式,降低小麦地上部和根部的Cd含量与积累量,减轻细胞膜脂质的过氧化程度,进而缓解Cd胁迫对小麦幼苗生长的毒害作用.This research aimed to clarify the effects of exogenously applied chitosan on the physiological characteristics,antioxidant activities,and Cd accumulation of wheat(Triticum aestivum L.)seedlings under cadmium(Cd)stress and to identify the key indicators based on the partial least squares model.The wheat variety studied was Bainong207(BN207),and Cd-stress was achieved by growing seedlings in a hydroponic culture experiment with 10 and 25µmol·L^(-1)Cd2+added to the culture solution.It was found that both Cdstress at 10 and 25µmol·L^(-1)significantly inhibited the chlorophyll content,photosynthesis,and biomass accumulation of wheat seedlings.Seedling roots became shorter and thicker,and the lateral roots decreased under Cd-stress.The Cd-stress also increased H_(2)O_(2)and MDA accumulation and the degree of cell membrane lipid peroxidation and affected the activities of antioxidant enzymes such as superoxide dismutase(SOD)and peroxidase(POD).Under Cd stress,exogenous chitosan decreased the Cd content in the aboveground and underground parts of wheat by 13.22%-21.63%and 7.92%-28.32%and reduced Cd accumulation in the aboveground and underground parts by 5.37%-6.71%and 1.91%-4.09%,respectively.Whereas exogenous chitosan application significantly reduced the content of H_(2)O_(2)in roots and aboveground parts of wheat by 38.21%-47.46%and 45.81%-55.73%and MDA content by 37.65%-48.12%and 29.87%-32.51%,it increased the activities of SOD and POD in roots by 2.78%-5.61%and 13.81%-18.33%,respectively.In summary,exogenous chitosan can improve the photosynthetic characteristics and antioxidant enzyme activities of wheat seedlings under Cd stress,reduce the content and accumulation of Cd in the root and aboveground parts of wheat,and alleviate the damage of lipid peroxidation to the cell membrane.All of these results provide the basal data for the application of exogenous chitosan to alleviate Cd toxicity to wheat seedlings.

关 键 词：壳聚糖(CTS) 镉(Cd)胁迫 冬小麦 生理特性 抗氧化系统 

分 类 号：X171.5[环境科学与工程—环境科学]