Tropospheric ozone (O3) is a potent oxidant that can harm plants, making it a key focus of research in ecology and agriculture. However, comprehensive reviews about the developmental history of O3 research on plants are lacking. This review utilized Citespace software to unveil the evolution of the main research themes over time, which correlated with three distinct developmental periods. During the first period, researchers primarily focused on the impact of O3 on photosynthesis and plant defense responses. As time progressed, more in-depth investigations were undertaken, including determining the critical levels at which O3 damage to plants occurred, analyzing the source-sink carbon balance and carbon allocation, assessing food security based on risk evaluation, identifying quantitative trait loci associated with O3 tolerance, conducting transgenic research, and exploring the combined effect of multiple stressors on vegetation within the context of climate change. Despite these insights, several gaps and challenges remain, that merit future considerations. Greater research efforts should focus on (1) insufficient studies on the combined effects of O3, CO2, and drought in the context of global warming; (2) intermittent elevated O3 events and plant recovery mechanisms under low O3 concentration; (3) reproductive and renewal capacity of species, and t O3 effects on community stability or composition; (4) updating O3 flux measurements to reflect effective O3 flux when O3 index is applied, and challenges in determining species-specific phytotoxicity threshold; and (5) O3-tolerance gene screening and breeding.

It has been confirmed that microplastics (MPs) are present in the environment. This study simulated secondary PE-MPs via aging and mechanical processes to evaluate their effects on Pak choi (Brassica rapa L.) over 21 d. Two common pollutants, dichlorodiphenyltrichloroethane (DDT) and naphthalene, were used in the combined toxicity tests. The results indicated that the growth of Pak choi was significantly inhibited after exposure to secondary PE-MPs, and the combined effects were antagonistic, owing to the adsorption capacity of secondary PE-MPs to DDT and naphthalene. Oxidative stress in Pak choi can be markedly affected, leading to oxidative damage to plant cells. The moisture content, soil bulk density, soil density, cation exchange capacity (CEC), and FDA hydrolase in the planted soils increased in the treated groups, and the TOC content changed significantly. We also found that the microbial composition of the soil in the DDT and naphthalene groups showed more significant alterations than that in the other groups. Alpha diversity analysis showed that species diversity increased in the combined groups but indicated a clear downward trend in the single MPs groups. This study suggests that secondary PE-MPs harm the growth of Pak choi and can change soil properties, revealing the harm to the ecosystem of MPs in the soil.