摘要
微塑料对作物生长构成了潜在威胁,而比较不同类型微塑料对作物生长的影响效应研究相对缺乏.本研究通过水培实验探究了5种常见微塑料(聚氯乙烯(PVC)、聚丙烯(PP)、聚苯乙烯(PS)、聚乙烯(PE)和聚对苯二甲酸乙二醇酯(PET))胁迫对水稻幼苗生长、生理响应、根表铁膜形成及镉(Cd)富集特征的影响.结果表明,相较于对照(CK),PP胁迫显著抑制水稻幼苗地上部鲜重、根部鲜重和地上部长度.而PVC、PS、PE和PET未表现出毒性效应,甚至呈轻微生长促进趋势.这5种微塑料胁迫均降低了水稻幼苗叶绿素a(除PE外)、叶绿素b(除PVC外)和叶绿素总量,其中以PP和PET对水稻幼苗叶绿素含量的影响较大.所有微塑料胁迫导致水稻幼苗活性氧(ROS)积累和丙二醛(MDA)含量增加,其中PP显著增加H_(2)O_(2)含量和O_(2)^(-)·含量(分别为对照的1.57倍和1.33倍),并增加丙二醛(MDA)含量(32.43%).此时,水稻幼苗通过提升超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性缓解氧化损伤.由此说明,这5种微塑料中以PP对水稻幼苗的毒性效应最强.所有微塑料胁迫均促进了水稻根表铁膜形成(DCB-Fe含量增加1.85%~10.06%),但PP和PET胁迫提升了铁膜中DCB-Cd含量,而PVC、PS和PE胁迫会降低铁膜中DCBCd含量.值得注意的是,不同类型微塑料胁迫对水稻幼苗富集Cd的影响存在差异,PVC和PP胁迫处理增加了根部Cd含量,PS胁迫处理增加了地上部Cd含量,说明微塑料胁迫存在可能加剧水稻富集重金属的风险.本研究为深入理解不同类型微塑料的生态环境效应提供了科学依据.
Microplastics pose a potential threat to crop growth,yet comparative studies on the differential effects of various microplastic types remain limited.This study investigated the impacts of five common microplastics(polyvinyl chloride(PVC),polypropylene(PP),polystyrene(PS),polyethylene(PE),and polyethylene terephthalate(PET))on rice seedling growth,physiological responses,root surface iron plaque formation,and cadmium(Cd)enrichment through hydroponic experiments.Results demonstrated that,compared to the control(CK),PP stress significantly inhibited shoot fresh weight,root fresh weight,and shoot length of rice seedlings.In contrast,PVC,PS,PE,and PET exhibited no toxic effects and even showed slight growth-promoting trends.All tested five microplastics reduced chlorophyll a(except PE),chlorophyll b(except PVC),and total chlorophyll content,with PP and PET exerting the strongest inhibitory effects.All tested five microplastics induced the reactive oxygen species(ROS)accumulation and elevated malondialdehyde(MDA)levels.Specifically,PP significantly increased H_(2)O_(2) and O_(2)^(-)·levels(1.57-fold and 1.33-fold than CK,respectively)and MDA level by 32.43%.In response,rice seedlings mitigated oxidative damage by enhancing superoxide dismutase(SOD)and catalase(CAT)activities.These findings highlight that among the five microplastics,PP exhibits the most toxic effects on rice seedlings.All microplastic promoted iron plaque formation(DCB-Fe content increased by 1.85%~10.06%).However,PP and PET enhanced DCB-Cd content in iron plaque,while PVC,PS,and PE reduced it.Notably,different microplastic types showed varied impacts on Cd accumulation.PVC and PP increased root Cd content,while PS treatment elevated shoot Cd content,suggesting that microplastic exposure may exacerbate heavy metal accumulation risks in rice.This study provides scientific basis for understanding the ecological effects of different microplastic types.
作者
田甜
刘雅慧
于彦航
郭孝玉
陈春乐
TIAN Tian;LIU Yahui;YU Yanhang;GUO Xiaoyu;CHEN Chunle(Fujian Provincial Key Laboratory of Resources and Environment Monitoring&Sustainable Management and Utilization,Sanming 365004;College of Environment and Safety Engineering,Fuzhou University,Fuzhou 350108;School of Resources and Chemical Engineering,Sanming University,Sanming 365004)
出处
《环境科学学报》
北大核心
2025年第9期447-456,共10页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.41801279)
福建省自然科学基金(No.2023J011026)
福建省资源环境监测与可持续经营利用重点实验室开放基金(No.ZD1803)。
关键词
微塑料
水稻幼苗
活性氧
抗氧化酶
铁膜
镉富集
microplastic
rice seedlings
reactive oxygen species(ROS)
antioxidant enzymes
iron plaque
cadmium(Cd)enrichment
