Pb、Zn和Cd复合重金属潜在超富集植物的筛选与胁迫响应特征  

Screening and Stress Responsive Characteristics of Potential Hyperaccumulator of Pb,Zn,and Cd Compound Heavy Metals

作　　者：范拴喜 张楠[2,3] 孙旻涵 侯宪东 FAN Shuan-xi;ZHANG Nan;SUN Min-han;HOU Xian-dong(Joint Technology Innovation Center for Land Engineering and Human Settlements of Shaanxi Land Engineering Construction Group Co.,Ltd.,and Xi'an Jiaotong University,Xi'an 710049,China;Department of Geography and Environment,Baoji University of Arts and Sciences,Baoji 721013,China;Key Laboratory of Disaster Monitoring and Mechanism Simulation of Shaanxi Province,Baoji 721013,China)

机构地区：[1]陕西地建西安交大土地工程与人居环境技术创新中心,西安710049 [2]宝鸡文理学院地理与环境学院,宝鸡721013 [3]陕西省灾害监测与机理模拟重点实验室,宝鸡721013

出　　处：《环境科学》2024年第8期4870-4882,共13页Environmental Science

基　　金：陕西地建-西安交大土地工程与人居环境技术创新中心开放基金项目(2021WHZ0086);陕西省科技厅自然科学基金项目(2020SF-438)。

摘　　要：为了筛选Pb、Zn和Cd复合重金属超富集植物,对宝鸡市典型铅锌矿和冶炼厂区优势植物进行调查、采样和分析,初步筛选出一种潜在的Pb、Zn和Cd复合重金属超富集植物,并采用土培盆栽试验观测其在Pb、Zn和Cd复合重金属胁迫下叶绿素(叶绿素a、叶绿素b、类胡萝卜素、总叶绿素)、抗氧化酶(SOD、CAT、POD)和其他生理指标(MDA、脯氨酸)的响应特征,再通过大田试验,进一步验证并确定了其对Pb、Zn和Cd复合重金属的富集能力,以期为Pb、Zn和Cd复合重金属污染土壤修复提供科学依据和技术支撑.结果表明,野外调查发现聚合草对Pb、Zn和Cd的富集量、富集系数(BCF)和转移系数(TF)均满足国际上超富集植物指标限值要求,是一种潜在的Pb、Zn和Cd复合重金属超富集植物;土培盆栽试验显示,随着Pb、Zn和Cd复合重金属胁迫梯度的提高,聚合草叶片中叶绿素a、叶绿素b和总叶绿素含量逐渐降低,直至胁迫梯度大于等于Ⅳ时,导致植物光合系统紊乱;蓖麻叶片中的叶绿素含量呈现“低促高抑”现象,而胁迫过高则激发了自身其他保护系统使得毒害减轻而升高;另外,与CK相比,聚合草和蓖麻的叶绿素a、叶绿素b、类胡萝卜素和总叶绿素各自均存在显著性差异(P<0.05).聚合草和蓖麻叶片中的SOD酶活性均呈现先增加后降低再增加的趋势;聚合草叶片中CAT酶活性先升后降的趋势,呈现“低促高抑效应”,而蓖麻叶片中CAT酶活性呈现持续降低的趋势;聚合草叶片中POD酶活性总体呈现增加趋势,而蓖麻叶片中POD酶活性先升后降低再升高;聚合草叶片中MDA含量总体呈现下降趋势,而蓖麻叶片中MDA含量总体呈上升特征;此外,各胁迫梯度之间,聚合草和蓖麻的SOD、CAT、POD、MDA及脯氨酸均存在显著性差异(P<0.05).大田试验结果表明,聚合草对Pb、Zn和Cd的富集量、BCF和TF均可以达到超富集植物指标限值要求,是一种潜在的Pb、ZTo screen for Pb,Zn,and Cd composite heavy metal hyperaccumulator plants,a survey,sampling,and analysis of dominant plants in typical lead-zinc mines and smelter areas in Baoji City were conducted.Potential Pb,Zn,and Cd composite heavy metal hyperaccumulator plants were initially screened,and a pot experiment of soil cultivation was carried out to observe the response characteristics of chlorophyll(chlorophyll a,chlorophyll b,carotenoids,and total chlorophyll),antioxidant enzymes(SOD,CAT,and POD),and other physiological indicators(MDA and proline)under the stress of Pb,Zn,and Cd composite heavy metals.A field experiment was also conducted to further verify and determine their enrichment ability for Pb,Zn,and Cd composite heavy metals,aiming to provide scientific basis and technical support for the remediation of Pb,Zn,and Cd composite heavy metal-polluted soil.The field survey revealed that Symphytum officinale L.met the international hyperaccumulator plant index requirements for the enrichment of Pb,Zn,and Cd,with enrichment quantity,bioconcentration factor(BCF),and transfer factor(TF)all meeting the requirements.It was a potential hyperaccumulator plant for Pb,Zn,and Cd composite heavy metals.The soil cultivation pot experiment showed that as the gradient of Pb,Zn,and Cd composite heavy metal stress increased,the content of chlorophyll a,chlorophyll b,and total chlorophyll in S.officinale L.leaves gradually decreased,causing disruption to the plant's photosynthetic system when the gradient was greater than or equal to IV.The chlorophyll content in Ricinus communis L.leaves exhibited a“low-stimulation-high-inhibition”phenomenon,while excessive stress stimulated the activation of its own protective systems,leading to reduced toxicity.In addition,there were significant differences(P<0.05)in the content of chlorophyll a,chlorophyll b,carotenoids,and total chlorophyll between S.officinale L.and R.communis L.both compared to the control treatment and between stress gradients.The SOD activity in the leaves of S.of

关 键 词：Pb、Zn和Cd复合污染 超富集植物 生理特性 植物修复 聚合草 蓖麻 

分 类 号：X171.5[环境科学与工程—环境科学]