• 关键词：微塑料  镉  超富集植物  东南景天  叶芽鼠耳芥  富集  生长特性

• 基金项目：山西省自然科学基金（No.201901D111216）；山西省重点研发计划重点项目（No.201903D211012-05）；山西省1331工程资助项目（No.20211331-15）；山西省回国留学人员科研资助项目（No.2021-069）；山西省优秀博士来晋工作奖励基金（No.SXBYKY2021038）；山西农业 大学科技创新基金项目（No.2020BQ55）

• 宁瑞艳
• 山西农业大学资源环境学院，太谷 030801

• 刘娜
• 山西农业大学资源环境学院，太谷 030801

• 程红艳
• 山西农业大学资源环境学院，太谷 030801

• 陈瑗瑗
• 山西农业大学资源环境学院，太谷 030801

• 张海波
• 山西农业大学资源环境学院，太谷 030801

• 罗渊
• 山西农业大学资源环境学院，太谷 030801

• 王效举
• 日本埼玉县环境科学国际中心，日本埼玉 347-0115

• 摘要：在生态系统中，微塑料与重金属的共同暴露已然不可避免，目前关于二者复合污染的研究多集中于农作物，而对超富集植物的研究仍比较缺乏.基于此，本文探究了微塑料、重金属镉和二者复合效应对超积累植物东南景天和叶芽鼠耳芥生长特性和镉富集的影响.选取东南景天和叶芽鼠耳芥为试验对象，通过水培试验揭示聚苯乙烯微塑料（mPS，0、100、500 mg·L^-1）与重金属镉（Cd，0、50、200、500、1000 μmol·L^-1）单一及其复合污染对两种植物生长（生物量、根长、株高）和镉富集的影响.结果表明，单一微塑料处理下，微塑料对东南景天和叶芽鼠耳芥的生长起促进作用，当微塑料浓度为500 mg·L^-1时，东南景天地上部和根部、叶芽鼠耳芥地上部和根部鲜重较对照组分别增长了25.4%、143.1%、160.6%和127.1%，东南景天和叶芽鼠耳芥的根长较对照组分别显著增加了21.6%和42.3%；单一镉胁迫下，东南景天和叶芽鼠耳芥的生长被抑制，且随着培养液中镉浓度的增加，植株体内的镉含量不断增加；微塑料-镉复合试验（镉浓度200 μmol·L^-1）中，微塑料促进了东南景天和 叶芽鼠耳芥对镉的吸收，且微塑料浓度越高，促进作用越明显，当微塑料浓度为500 mg·L^-1时，东南景天和叶芽鼠耳芥地上部镉含量较未添加微塑料组分别显著增加了37.7%和100.7%，根部镉含量较未添加微塑料组分别显著增加了72.8%和50.8%.微塑料的添加增强了镉对东南景天的毒害作用，当微塑料浓度为500 mg·L^-1时，东南景天地上部、根部鲜重较未添加微塑料组分别降低了23.9%和28.1%，干重分别降低了22.9%和41.5%.相反，微塑料-镉复合试验（微塑料浓度为500 mg·L^-1）中，微塑料对叶芽鼠耳芥生长的促进作用占主导地位，最终表现为减弱了镉对叶芽鼠耳芥生长的抑制作用，叶芽鼠耳芥地上部、根部鲜重较未添加微塑料组分别增加了75.2%和108.5%，干重分别增加了10.5%和56.3%.研究表明，微塑料的添加促进了东南景天和叶芽鼠耳芥对镉的吸收，增强了镉对东南景天生长的抑制作用，但当微塑料浓度为500 mg·L^-1时减弱了对叶芽鼠耳芥的毒害作用.

• Abstract：The co-exposure of microplastics and heavy metals has become inevitable in soil ecosystems.At present，the combined pollution of microplastics and heavy metals mostly occurred in crops，while the research on hyperaccumulators is still lacking.Exploring the effects of microplastics，cadmium （Cd），and their combination on the growth and Cd accumulation of hyperaccumulators （Sedum alfredii Hance and AHG347 winter-clean）.Hyperaccumulators，Sedum alfredii Hance and AHG347 winter-clean，were selected as the test objects，and the hydroponic experiment was designed to reveal the effects of single and combined pollution of polystyrene microplastics （0，100，500 mg·L^-1） and Cd （0，50，200，500，1000 μmol·L^-1） on the growth and Cd accumulation of two plants.Under single microplastics treatment，the microplastics promoted the growth of Sedum alfredii Hance and AHG347 winter-clean.When the concentration of microplastics was 500 mg·L^-1，the fresh weight of aboveground and root of Sedum alfredii Hance increased by 25.4% and 143.1% compared with control，while the AHG347 winter-clean increased by 160.6% and 127.1%，respectively.The root lengths of Sedum alfredii Hance and AHG347 winter-clean significantly increased by 21.6% and 42.3% compared with control，respectively.Under single Cd treatment，the growths of Sedum alfredii Hance and AHG347 winter-clean were inhibited，and the Cd concentration in the plant increased as the Cd concentration in the nutrient solution increased.In the microplastics-Cd experiment （Cd concentration was 200 μmol·L^-1），the microplastics promoted the accumulation of Cd in Sedum alfredii Hance and AHG347 winter-clean，and the higher the concentration of microplastics，the more obvious the promotion effect.When microplastics concentration was 500 mg·L^-1，the Cd concentrations in aboveground and root of Sedum alfredii Hance and AHG347 winter-clean were significantly increased by 37.7%，72.8% and 100.7%，50.8%，compared with control，respectively.Microplastics enhanced the toxic effect of Cd on Sedum alfredii Hance，and when the microplastic concentration was 500 mg·L^-1，the fresh weights of the aboveground and root of Sedum alfredii Hance were reduced by 23.9% and 28.1% compared with control，while the dry weight decreased by 22.9% and 41.5%，respectively.Differently，in the microplastics-Cd experiment （microplastics concentration was 500 mg·L^-1），microplastics played a dominant role in promoting the growth of AHG347 winter-clean，finally weakened the inhibitory effect of Cd on the growth of AHG347 winter-clean.The fresh weights of the aboveground and root of AHG347 winter-clean increased by 75.2% and 108.5% compared with control，while the dry weights increased by 10.5% and 56.3%，respectively.The study showed that the addition of microplastics promoted the accumulation of Cd in Sedum alfredii Hance and AHG347 winter-clean，strengthened the inhibitory effect of Cd on the growth of Sedum alfredii Hance，but when the microplastics concentration was 500 mg·L^-1，the toxic effect of Cd on AHG347 winter-clean was weakened.

• Key words：microplastic  cadmium  hyperaccumulator  Sedum alfredii Hance  AHG347 winter-clean  accumulation  growth characteristics

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