Nano-titanium dioxide (nano-TiO₂) can alleviate oxidative damage in plants subjected to abiotic stress, interfere with related gene expression, and change metabolite content. Polylactic acid (PLA) microplastics can inhibit plant growth, induce oxidative stress in plant cells, and alter the biophysical properties of rhizosphere soil. In this study, untargeted metabolomics (LC-MS) and RNA-seq sequencing were performed on radish root cells exposed to nano-TiO₂ and PLA. The results showed that nano-TiO₂ alleviated the growth inhibition of radish roots induced by PLA. Nano-TiO₂ alleviated PLA-induced oxidative stress, and the activities of SOD and POD were decreased by 28.6% and 36.0%, respectively. A total of 1673 differentially expressed genes (DEGs, 844 upregulated genes, and 829 downregulated genes) were detected by transcriptome analysis. Metabolomics analysis showed that 5041 differential metabolites were involved; they mainly include terpenoids, fatty acids, alkaloids, shikimic acid, and phenylpropionic acid. Among them, phenylpropanoid biosynthesis as well as flavone and flavonol biosynthesis were the key metabolic pathways. This study demonstrates that nano-TiO₂ mitigates PLA phytotoxicity in radish via transcriptional and metabolic reprogramming of phenylpropanoid biosynthesis. These findings provide important references for enhancing crop resilience against pollutants and underscore the need for ecological risk assessment of co-existing novel pollutants in agriculture.

Polyvinyl chloride (PVC) is commonly employed as mulch in agriculture to boost crop yields. However, its toxicity is often overlooked. Due to its chemical stability, resistance to degradation, and the inadequacy of the recycling system, PVC tends to persist in farm environments, where it can decompose into microplastics (MPs) or nanoplastics (NPs). The radish (Raphanus sativus L.) was chosen as the model plant for this study to evaluate the underlying toxic mechanisms of PVC NPs on seedling growth through the integration of multi-omics approaches with oxidative stress evaluations. The results indicated that, compared with the control group, the shoot lengths in the 5 mg/L and 150 mg/L treatment groups decreased by 33.7% and 18.0%, respectively, and the root lengths decreased by 28.3% and 11.3%, respectively. However, there was no observable effect on seed germination rates. Except for the peroxidase (POD) activity in the 150 mg/L group, all antioxidant enzyme activities and malondialdehyde (MDA) levels were higher in the treated root tips than in the control group. Both transcriptome and metabolomic analysis profiles showed 2075 and 4635 differentially expressed genes (DEGs) in the high- and low-concentration groups, respectively, and 1961 metabolites under each treatment. PVC NPs predominantly influenced seedling growth by interfering with plant hormone signaling pathways and phenylpropanoid production. Notably, the reported toxicity was more evident at lower concentrations. This can be accounted for by the plant’s “growth-defense trade-off” strategy and the manner in which nanoparticles aggregate. By clarifying how PVC NPs coordinately regulate plant stress responses via hormone signaling and phenylpropanoid biosynthesis pathways, this research offers a scientific basis for assessing environmental concerns related to nanoplastics in agricultural systems.

Organohalide-respiring bacteria (OHRB) facilitate the reductive dehalogenation of toxic halogenated compounds in the environment, which supports their growth and proliferation. Research conducted on OHRB has achieved notable advancements. However, given the intricacy of the ecosystem and the methodologies employed for microbial isolation, numerous constraints persist. Further exploration is imperative to elucidate the physiological characteristics, ecological functions, and technological applications of OHRB. This study aimed to evaluate the outcomes and insights of prior research via a bibliometric analysis of three obligate OHRB genera—Dehalococcoides, Dehalobacter, and Dehalogenimonas—over a three-decade period from 1994 to 2024, based on the Web of Science (WOS) database. The results show that research on these three bacterial genera has advanced in sequence since the initiation of studies in this field. The research area encompasses the identification and isolation of novel OHRB species, the gene sequencing of related enzymes, and the role of microorganisms in the remediation of environmental pollutants, reflecting a gradual transition from individual investigations of OHRB to the applications of microorganisms in remediating complex environmental pollution. This study systematically reviewed the past research history of this field and conducted an in-depth analysis of research hotspots. The integration of this analysis with technological development trends and practical application requirements provides a theoretical basis and innovative concepts for future research directions in the field of ecological environment restoration.