Plant Trait Regulation Enabled by Nanoplastic Nucleic Acid Carriers

Nanoplastic pollutants have raised concerns about their potential impacts on plant physiology. In this study, RNA interference technology (RNAi) was leveraged to verify the intracellular regulation of nanoplastic nucleic acid carriers (NNAC) on plant traits. The results revealed that positively charged polystyrene nanoplastics (PS, 20 nm) can efficiently adsorb small interfering RNA (siRNA) at a mass ratio of 1:5 (siRNA-PS) through electrostatic interactions, forming stable siRNA-PS complexes resistant to enzymatic degradation. The red fluorescence was observed in tobacco leaf cells, providing evidence that Cy3-siRNA-PS has successfully traversed the cell wall barrier and been internalized. Meanwhile, the targeted siRNA-PS effectively induces pronounced fluorescence quenching of green fluorescent protein (GFP) in tobacco leaves, decreasing by 97.6% after 24 h. Similarly, the vibrant red flowers of glory were tuned to a faded state through the manipulation of color-controlled genes, particularly the mRNA expression of chalcone isomerase (CHI) reduced by 69.4%. Nevertheless, the expression of the GFP gene in tobacco leaves has largely reverted to the baseline levels observed in the control group after 4 days, highlighting the transient and reversible nature of this nongenetic regulation. Overall, this study uncovers the role of nanoplastic carriers, enhancing our understanding of nanoplastic biosafety and providing a foundation for the phytotoxicity of new nanopollutants.