刚毛藻对砷的吸收及生理响应  

Arsenic Uptake and Defense Responses in Cladophora rupestris

作　　者：张庐生 强震宇 王琴 何梓学 曹德菊[1] 刘赵文 ZHANG Lusheng;QIANG Zhenyu;WANG Qin;HE Zixue;CAO Deju;LIU Zhaowen(College of Resources and Environment,Anhui Agricultural University,Hefei 230036,China)

机构地区：[1]安徽农业大学资源与环境学院,安徽合肥230036

出　　处：《环境科学与技术》2022年第10期11-17,共7页Environmental Science & Technology

基　　金：国家自然科学基金项目(41877418);国家级大学生创新基金(202210364047);安徽省大学生创新创业项目(S202110364115)。

摘　　要：为了探究刚毛藻对As(Ⅲ)的耐性机制,采用室内水培实验,在不同浓度As(Ⅲ)胁迫(0、0.5、1.0、2.5、5.0、7.5、10.0 mg/L)条件下连续培养7 d,测定了刚毛藻的叶绿素、丙二醛(MDA)、可溶性糖和脯氨酸(渗透调节物质)等指标响应情况,研究了刚毛藻对As的吸收,采用Langmuir和Freundlich等温吸附模型对刚毛藻As吸收进行拟合,并采用透射电镜解析其超微结构。结果表明:As(Ⅲ)胁迫在低浓度条件下(2.5 mg/L)对刚毛藻叶绿素含量有促进效应,叶绿素总量最大为2.236 mg/kg,吸收光谱在红橙光区发生红移,在蓝光区发生蓝移。脯氨酸和可溶性糖含量与As(Ⅲ)浓度呈现显著的负相关(P<0.05)。随着As(Ⅲ)胁迫浓度的增加,刚毛藻MDA含量先增后降然后趋于稳定,刚毛藻对As的吸收增强,且符合Freundlich等温吸附模型(R^(2)=0.99)。TEM结果显示,随着As(Ⅲ)胁迫浓度的增加,刚毛藻细胞壁变薄褶皱,发生质壁分离,叶绿体发生肿胀解体,保卫细胞变形,气孔扩张。由此,刚毛藻对低浓度(2.5 mg/L)As(Ⅲ)具有一定的耐受性。实验结果为研究刚毛藻对As胁迫的响应及刚毛藻在水体修复方面的生态应用提供一定的理论依据。In order to explore the mechanism of tolerance to arsenic As(Ⅲ)in C.rupestris,an indoor hydroponic experiment was used to continuously culture 7 days under different As(Ⅲ)stresses(0,0.5,1.0,2.5,5.0,7.5,10.0 mg/L).The response of chlorophyll,MDA(malondialdehyde),soluble sugar,and proline(osmotic regulator)of C.rupestris was measured,and the absorption of As by C.rupestris was studied.The Langmiur and Freundlich adsorption isotherm models were used for As absorption was fitted and observed with transmission electron microscopy(TEM).The results showed that As stress had an obvious stimulant effect on the chlorophyll content of C.rupestris.The maximum amount of chlorophyll was 2.236 mg/kg.The absorption spectrum of redshift in red-orange region and blueshift in blue-light region.The content of proline and soluble sugar was significantly negatively correlated with the concentration of As(P<0.05).In the wake of the increase of As stress concentration,the content of MDA in the C.rupestris increased,decreased,then tended to be stable.TEM results showed that,with the increase of arsenic stress concentration,the cell wall of C.rupestris became thinner and folded,the plasmodesm was separated,the chloroplast was swollen and disintegrated,the guard cells were deformed,and the stomata disappeared.The experimental results provide a certain theoretical basis for research on the response of C.rupestris to As stress and the ecological application of C.rupestris in water remediation.

关 键 词：刚毛藻 砷 超微结构 叶绿素 丙二醛 Freundlich拟合 

分 类 号：X172[环境科学与工程—环境科学]