Institute of Biological and Medical Engineering, Guangdong Academy of Sciences, Guangzhou 510316, China; Guangdong Biomaterials Engineering Technology Research Center, Guangzhou 510316, China.
Institute of Biological and Medical Engineering, Guangdong Academy of Sciences, Guangzhou 510316, China; Guangdong Biomaterials Engineering Technology Research Center, Guangzhou 510316, China.
Sci Total Environ. 2022 Jul 1;828:154579. doi: 10.1016/j.scitotenv.2022.154579. Epub 2022 Mar 15.
Extensive use of plastic film mulch has resulted in accumulation of a large amount of residual plastic, which will eventually fragment into microplastics in agricultural soils. However, it is unclear how microplastics from plastic mulch film affect crops. To address this issue, rice plants exposed to microplastics derived from poly(butyleneadipate-co-terephthalate) (PBAT)-based biodegradable mulch film (BM) and polyethylene (PE) mulch film (PM) were investigated for plant growth, physio-biochemical processes, and gene expressions. Both types of microplastics significantly reduced the height and dry weight of rice plant. Oxidative stress was induced by microplastics in rice shoot and root, with levels of ROS relatively higher under treatment PM than that under treatment BM. Transcriptomic data showed that more genes were down-regulated by treatment PM than that by treatment BM. Genes encoding ammonium and nitrate transporters were down-regulated by both types of microplastics in rice roots at vegetative stage, whereas up-regulated at reproductive stage, as compared to their respective treatment with no microplastics (CK). Similar results regarding phenylpropanoid biosynthesis pathway and lignin content were also observed in rice roots. Net photosynthetic rate and SPAD value were significantly inhibited by treatments BM and PM in rice shoot, and the expression of genes involved in light reaction was reduced at vegetative stage, whereas there were no differences of them at reproductive stage, as compared to their respective treatment CK. Our study suggests that microplastics from BM and PM both affect the growth of rice plants via nitrogen metabolism and photosynthesis. The negative effects imposed by both types of microplastics on rice plant can be mitigated with the growth of plants, and the negative effects of microplastics from PE mulch film on rice plant are relatively stronger than that from the PBAT-based biodegradable film.
大量使用塑料薄膜导致大量残余塑料的积累，这些残余塑料最终会在农业土壤中碎裂成微塑料。然而，目前尚不清楚塑料薄膜微塑料如何影响作物。为了解决这个问题，研究了暴露于源自聚（丁二酸丁二醇酯-己二酸酯）（PBAT）基可生物降解地膜（BM）和聚乙烯（PE）地膜（PM）的微塑料的水稻植株的生长、生理生化过程和基因表达。这两种类型的微塑料都显著降低了水稻植株的高度和干重。微塑料在水稻茎和根中诱导了氧化应激，PM 处理下的 ROS 水平相对高于 BM 处理下的水平。转录组数据表明，PM 处理比 BM 处理下调了更多的基因。在营养阶段，两种类型的微塑料都下调了水稻根中铵和硝酸盐转运蛋白基因的表达，而在生殖阶段则上调了这些基因的表达，与无微塑料（CK）处理相比。在水稻根中也观察到类似的关于苯丙烷生物合成途径和木质素含量的结果。BM 和 PM 处理均显著抑制了水稻茎中的净光合速率和 SPAD 值，并且在营养阶段，与 CK 处理相比，与光反应相关的基因表达减少，而在生殖阶段则没有差异。我们的研究表明，BM 和 PM 中的微塑料均通过氮代谢和光合作用影响水稻的生长。两种类型的微塑料对水稻植株的负面影响可以随着植物的生长而减轻，PE 地膜微塑料对水稻植株的负面影响相对大于 PBAT 基可生物降解地膜的负面影响。
