Cd胁迫对银中杨幼苗金属元素代谢及其氧化应激的影响  

Effects of Cd stress on metal element metabolism and oxidative stress of Populus alba×P.berolinensis ramet

作　　者：徐金生 姜礅 严善春[1] XU Jinsheng;JIANG Dun;YAN Shanchun(College of Forestry,Northeast Forestry University,Harbin 150040)

机构地区：[1]东北林业大学林学院,哈尔滨150040

出　　处：《安徽农业大学学报》2023年第6期1000-1005,共6页Journal of Anhui Agricultural University

基　　金：中央高校基本科研业务费专项资金项目(2572017AA24)资助。

摘　　要：为了探究镉(Cd)胁迫对木本植物生长发育和生理特性的影响,以一年生盆栽银中杨(Populus alba×P. berolinensis)为研究对象,在土壤基质中添加4种含量的Cd(0、0.5、1.5或2.5mg·kg^(-1)土壤),分析Cd处理下银中杨的生长状况,以及叶片的必需金属营养元素、氧化损伤、抗氧化酶和非酶类抗氧化剂的含量或活性。在Cd各含量处理下,银中杨苗木的生长量和生物量均受到显著抑制,表现为苗高、根长和地径,以及叶、茎、根鲜重和干重均显著低于对照(P <0.05)。Cd处理显著提高银中杨叶片对Cd的富集含量,并显著扰乱银中杨叶片金属营养元素K、Ca、Cu、Zn、Mn和Mg的代谢平衡(P <0.05)。在Cd处理后的第30、40或50天,银中杨幼苗叶片中的超氧化物歧化酶、过氧化氢酶、过氧化物酶活性和丙二醛含量均显著升高(P <0.05),且各指标值在3个采样日期均与Cd含量呈正相关性。此外,Cd各处理组次生代谢产物(黄酮类和木质素)的含量,以及参与次生代谢的2种关键酶(苯丙氨酸解氨酶和多酚氧化酶)的活性均显著增加(P <0.05)。Cd胁迫通过氧化损伤导致银中杨幼苗生长迟缓和营养元素代谢紊乱;银中杨的抗氧化防御系统被激活,在一定程度上缓解了Cd暴露对其造成的毒性效应。To explore the effect of cadmium(Cd)stress on the growth,development and physiological charac-teristics of woody plants,annual pot plants of Populus alba×P.berolinensis ramet were used as the research object,four contents of Cd(at 0,0.5,1.5 and 2.5 mg·kg^(-1))were added to the soil substrate to analyze the growth status of Populus alba×P.berolinensis ramet under Cd treatment,as well as the content or activity of necessary the essential metal-trophic elements,oxidative damage,or activities of antioxidant enzymes and contents in the non-enzymatic antioxidants of leaves.Under Cd treatments at different levels,the growth amount and biomass of Populus alba×P.berolinensis ramet were significantly inhibited,and the ramet height,root length and ground diameter,fresh weight and dry weight of leaf,stem and root were significantly lower than those of the control(P<0.05).Cd exposure sig-nificantly increased the accumulated Cd concentrations in the leaves.Cd treatments resulted in a nutritional elements imbalance in the leaves of Populus alba×P.berolinensis ramet,especially on the metabolisms of K,Ca,Cu,Zn,Mn and Mg.SOD,CAT,POD and MAD contents in the leaves of Populus alba×P.berolinensis ramet were significant-ly increased on days 30,40,or 50 after Cd treatment(P<0.05),and the values of each index were positively corre-lated with Cd content at all three sampling date.Furthermore,the contents of secondary metabolites(flavonoids and lignin)at each concentration of Cd and the activity of two key enzymes(PAL and PPO)involved in secondary me-tabolism increased significantly(P<0.05).Cd stress induced a reduced growth and nutritional elements imbalance in Populus alba×P.berolinensis ramet via oxidative damage,while the activated antioxidant defense system somewhat mitigated the phytotoxic effects of Cd exposure on Populus alba×P.berolinensis ramet.

关 键 词：银中杨 金属营养元素 氧化损伤 抗氧化 CD胁迫 

分 类 号：X173[环境科学与工程—环境科学] X53[农业科学—林木遗传育种] S792.11[农业科学—林学]