The Effects of Temperature Increase and Nanoplastics on Germination and Early Growth of Crop

Nanoplastics (NPs) are plastic particles with a size of less than 1μm, and they have the potential to enter the human body through the food chain. In the context of climate change, the combined effects of global warming and NPs on surrounding ecosystems remain largely understudied. Therefore, this study analyzed the impact of temperature increase under laboratory conditions and NPs exposure on plant germination and early growth of radish (Raphanus sativus L.) Radish seeds were placed onto petri dishes and PS NPs (polystyrene nanoplastics) were added. The PS NPs that are 100, 200, and 400 nm in diameter were applied at 0, 100, 500, and 1000 mg L-1. To simulate different climate change scenarios, these seeds were incubated in chambers set to temperatures of ambient, approx. 22℃, ambient +3℃, and ambient +6℃ in consideration of the germination temperature of radish. The experimental period was 8 days in total, and the germination rate was measured three times every 24 hours, and the root length and diameter were measured on the 8th day. PS NPs treatment increased the root growth of radish under the treatment of 100- and 200-nm PS NPs. The root length of radish was the longest under 200-nm PS NPs treatment, whereas the root diameter was the thickest under 100-nm PS NPs treatment, respectively. Temperature had a significant effect on the germination rate on day 1, and the germination rate was the lowest at 1000 mg L-1 of 100-nm and 100 mg L-1 of 400-nm PS NPs treatments at ambient + 3℃. Under 1000 mg L-1 of 100-nm PS NPs treatment, this trend lasted until day 3. The promotion or inhibition of crop growth due to NPs treatment may vary depending on the size and concentration of specific NPs, and the impact of NPs on seed germination and early growth of root crop is considered to differ due to various factors. We analyzed the effects of climate change and NPs on radish and discovered that germination rates and initial growth responses vary depending on different environmental factors in this study. Our finding is expected to contribute to assessing the risks associated with NPs pollution under rising temperatures associated with climate change and to establishing criteria for evaluating soil ecosystem health.