Influence of polyethylene microplastics on Brassica rapa:Toxicity mechanism investigation  

作　　者：Hao Wu Beibei He Bocheng Chen An Liu 

机构地区：[1]College of Chemistry and Environmental Engineering,Shenzhen University,Shenzhen,518060,China

出　　处：《Emerging Contaminants》2024年第3期354-362,共9页新兴污染物（英文）

基　　金：supported by Guangdong Basic and Applied Basic Research Foundation(2024A1515010371);National Natural Science Foundation of China(52170100,U21A2036).

摘　　要：Polyethylene microplastics(PE-MPs)have toxicity to ecological environment,including animals and plants.This study investigated the toxicity of photodegraded PE-MPs on Brassica rapa,which is a typical model plant and only have around a 30-day life cycle.It is noted that the presence of photodegraded PEMPs inhibited Brassica rapa growth since the stem length decreased by 11.94%-51.11%while the fresh weight and dry weight decreased by 18.56%e27.46%and 1.90%-6.91%respectively,compared to the blank group.PE-MPs receiving more light radiation became more hydrophobic.This inhibited PE-MPs entering the plant body along with the process of plant absorbing water.Furthermore,when PE-MPs were located in the lower soil layers,Brassica rapa reaching them needs a longer time,hence showing lower toxicity effect than the case of PE-MPs located in the upper soil layer.The research outcomes also indicated that malondialdehyde(MDA)contents in photodegraded PE-MPs exposure group increased by 1.37%-7.28%while the catalase activity(CAT)increased by 60.11%.This means that PE-MPs caused oxidative stress response in plants,inducing plants to resist external stress.Transcriptomic analysis results showed that Brassica rapa,which was affected by PE-MPs,significantly up-regulated genes related to the plant-pathogen interaction pathway while the ribosome pathway genes were significantly downregulated.This led to a decrease in growth rate and a decrease in the homeostatic level of the ribosomal subunit and hence resulting in abnormal leaf vein development.These conclusions indicated the toxic effect and damage mechanism of photodegraded PE-MPs on Brassica rapa.The novelty of this study was to use both univariate analysis and transcriptomic analysis to investigate how photodegraded PE-MPs exert toxicity on Brassica rapa.The results can provide a theoretical basis for revealing the influence of MPs on plant growth.

关 键 词：Microplastics POLYETHYLENE Toxicity mechanisms Plant growth 

分 类 号：Q94[生物学—植物学]