MgO NPs及其析出的Mg^2+对细叶蜈蚣草(Egeria najas)光合作用的影响  

Effects of MgO NPs and Their Released Mg^2+ on the Photosynthesis of Egeria najas

作　　者：郑博文 徐长山[1] 何惠敏 程亮 郭佳昕 刘晓男[1] Zheng Bowen;Xu Changshan;He Huimin;Cheng Liang;Guo Jiaxin;Liu Xiaonan(Key Laboratory of UV-Emitting Materials and Technology,Ministry of Education,Northeast Normal University,Changchun 130024,China)

机构地区：[1]东北师范大学紫外光发射材料与技术教育部重点实验室,长春130024

出　　处：《生态毒理学报》2020年第5期301-309,共9页Asian Journal of Ecotoxicology

基　　金：国家自然科学基金资助项目(11374046,11074030)。

摘　　要：以细叶蜈蚣草(Egeria najas)为受试植物,研究MgO NPs及其析出的Mg^2+对水生植物光合作用的影响。结果表明,MgO NPs抑制了光系统Ⅱ反应中心之间的连通性及受体侧的电子传递,而Mg^2+则提升了光系统活性和光能转化率,因而排除了MgO NPs中析出的Mg^2+对细叶蜈蚣草光合作用的毒性。对Mg^2+浓度的原位实时检测表明,MgO NPs悬浮液中Mg^2+浓度并非常数。在培养细叶蜈蚣草初期,悬浮液中Mg^2+析出浓度范围为0.3~1.0 mg·L^-1,随时间推移析出浓度逐渐增高并在24 h后达到饱和值0.7~2.4 mg·L^-1。未培养细叶蜈蚣草时悬浮液中析出的Mg^2+浓度要更大,24 h后浓度范围达到0.9~2.8 mg·L^-1。这些结果弥补了以往研究中未能对MgO NPs析出的Mg^2+浓度进行动态检测的不足。比较细叶蜈蚣草对MgO NPs悬浮液中和MgCl 2溶液中的Mg^2+的表观吸收量会发现MgO NPs抑制了细叶蜈蚣草对Mg^2+的吸收。Egeria najas was used as a test plant to study the effects of MgO NPs and their released Mg^2+on the photosynthesis of aquatic plants.The results showed that MgO NPs inhibited the connectivity between the photosystemⅡ(PSⅡ)reaction centers and the electron transport on the receptor side.But Mg^2+enhanced the activity of photosystem and the conversion efficiency of light energy,thus eliminated the toxicity of the released Mg^2+on the photosynthesis of Egeria najas.In situ real-time detection of Mg^2+concentration indicated that the Mg^2+concentration in the MgO NPs suspension was not constant.In the early stage of the cultivation of Egeria najas,the concentration of Mg^2+in the suspension ranged within 0.3~1.0 mg·L^-1.The concentration increased gradually with time and reached a saturation value of 0.7~2.4 mg·L^-1 after 24 h.The saturation concentration of Mg^2+in the suspension without Egeria najas in it was much higher,ranged within 0.9~2.8 mg·L^-1 after 24 h.These results made up for the lack of dynamic detection of Mg^2+concentrations in MgO NPs suspensions in previous studies.Comparing the apparent uptake of Mg^2+in MgO NPs suspension and MgCl 2 solution showed that MgO NPs inhibited the absorption of Mg^2+by Egeria najas.

关 键 词：MgO纳米粒子 MG^2+ 细叶蜈蚣草 光合作用 离子选择性微电极 叶绿素a荧光 

分 类 号：X171.5[环境科学与工程—环境科学]