GA3对Cu胁迫下菠菜幼苗矿质元素吸收、细胞超微结构的调控效应及其耐Cu机理研究  

Regulatory Effects of GA3 on the Absorption and Transport of Mineral Elements and Cell Ultrastructure of Spinacia oleracea Seedlings under Cu Stress and the Mechanism of Cu Tolerance

作　　者：公勤 李兆华[1,3] 王玲[1] 宋雅琦 康群[1] 戴同威 GONG Qin;LI Zhaohua;WANG Ling;SONG Yaqi;KANG Qun;DAI Tongwei(School of Resources and Environment,Hubei University,Wuhan 430062,China;Xinjiang Vocation College of Agriculture,Changji 831100,China;Hubei Rural Safe Drinking Water Engineering Technology Research Center,Wuhan 430062,China)

机构地区：[1]湖北大学资源环境学院,湖北武汉430062 [2]新疆农业职业技术学院,新疆昌吉831100 [3]湖北省农村安全饮水工程技术研究中心,湖北武汉430062

出　　处：《生态环境学报》2019年第9期1876-1885,共10页Ecology and Environmental Sciences

基　　金：湖北省自然基金重点项目（创新群体项目，2016CFA016)

摘　　要：为探究菠菜幼苗的耐Cu机理及赤霉素(GA3)对Cu胁迫下菠菜幼苗耐Cu机理的调控效应,比较了正常生长、Cu胁迫以及Cu与GA3复合作用(700mg·kg^-1Cu+0、3、5、10、20、40、60、80mg·L^-1GA3)3种条件下,菠菜幼苗生长量、氧化应激反应、脯氨酸和可溶性蛋白含量、Cu^2+积累、矿质元素吸收以及细胞超微结构等指标的变化。结果显示,与正常生长相比(C1),700mg·kg^-1Cu胁迫下(C2处理),幼苗叶部、根部的Cu含量显著增加(P<0.05),总鲜重和总干重分别下降了31.9%、40.9%,丙二醛(MDA)、O2^-和H2O2含量增至对照的0.12、1.48、0.69倍,Ca、Mg含量减少,细胞器肿胀,核膜、核仁消失,而脯氨酸和可溶性蛋白含量分别增加了55.4%、17.3%,N、P、K、Fe、Zn含量也有增加趋势,表明该植物具有较强的耐Cu性。与Cu胁迫相比(C2处理),喷施低于5mg·L^-1的GA3时(T1、T2处理),幼苗的叶部Cu含量显著下降(P<0.05),根部Cu含量显著增加(P<0.05),O2^-和H2O2含量显著减少(P<0.05),可溶性蛋白含量和植物生长量也显著增加(P<0.05);叶部N、K、Ca、Mg的含量平均增加了3.4%、84.4%、90.7%和130%,Zn含量平均减少了23.8%,根部P、K、Ca、Mg、Zn含量平均增加了46.4%、92.3%、17.8%、98.2%和39.9%,Fe含量平均减少了19.5%;叶部细胞内叶绿体肿胀现象基本消失,基粒片层堆叠紧密,均匀分布在叶绿体内部,液泡面积缩小,线粒体清晰可见。继续增加GA3浓度时,菠菜幼苗叶部Cu含量降幅减少、根部Cu含量增幅减少,氧化应激反应加剧,可溶性蛋白和矿质元素含量减少,生物量降低,叶肉细胞内叶绿体、线粒体、细胞核数量减少,结构模糊不清。综上所述,低于5mg·L^-1 GA3能有效缓解Cu胁迫对菠菜幼苗的毒害作用,超过此浓度会导致Cu胁迫伤害加重。研究结果可为Cu污染地区蔬菜栽培管理和重金属耐性品种筛选提供试验依据。To explore the Cu tolerance mechanism of Spinacia oleracea seedlings and the regulatory effects of GA3 on Cu tolerance mechanism of S. oleracea seedlings under Cu stress, in this study, the changes of growth, oxidative stress, proline and soluble protein contents, mineral element absorption and transport, Cu^2+ accumulation and cell ultrastructure of S. oleracea seedling were compared under normal growth, Cu stress (700 mg·kg^-1) and Cu stress +0, 3, 5, 10, 20, 40, 60 and 80 mg·L^-1 GA3. The results showed that compared with the normal growth (C1), the Cu contents in the leaves and roots significantly increased (P<0.05), the total fresh weight and total dry weight reduced by 31.9 % and 40.9%, respectively, the contents of MDA, O2^- and H2O2 increased by 0.12, 1.48 and 0.69 times, respectively, the contents of Ca and Mg reduced, with organelles swelling, nuclear membrane and nucleolus disappeared under 700 mg·kg^-1 Cu stress (C2), but proline and soluble protein contents increased by 55.4% and 17.3%, the contents of N, P, K, Fe, Zn also increased, the plant still maintained the survival state, indicating that the plant had strong Cu tolerance. When less than 5 mg·L^-1 GA3 concentration was sprayed on the Cu-stressed seedlings (T1 and T2), compared with Cu stress (C2), the Cu contents in leaves significantly decreased (P<0.05), while that in roots significantly increased (P<0.05), the contents of O2 - and H2O2 significantly reduced (P<0.05), soluble protein contents and biomass also significantly increased (P<0.05). Moreover, the average value of N, K, Ca and Mg increased by 3.4%, 84.4%, 90.7% and 130%, and the average value of Zn decreased by 23.8% in leaves, while the average value of P, K, Ca, Mg and Zn increased by 46.4%, 92.3%, 17.8%, 98.2% and 39.9%, the average value of Fe decreased by 19.5% in roots. The chloroplast swelling of the leaf cell basically disappeared, the lamellae of the basal granule were closely stacked and evenly distributed in chloroplast, the vacuole area reduced, the mitochondria were

关 键 词：GA3 CU胁迫 菠菜幼苗 矿质元素吸收和运输 细胞超微结构 

分 类 号：X171.5[环境科学与工程—环境科学]