Two aquaporins PIP1;1 and PIP2;1 mediate the uptake of neonicotinoid pesticides in plants.

Neonicotinoids (NEOs), a large class of organic compounds, are a type of commonly used pesticide for crop protection. Their uptake and accumulation in plants are prerequisites for their intra- and intercellular movements, transformation, and function. Understanding the molecular mechanisms that underpin NEOs uptake by plants is crucial for effective application, which remains elusive. Herein, we demonstrated that NEOs enter plant cells primarily through the transmembrane symplastic pathway and accumulate mainly in the cytosol. Two plasma membrane intrinsic proteins discovered in Brassica rapa, BraPIP1;1 and BraPIP2;1, were found to encode aquaporins (AQPs) that are highly permeable to NEOs in different plant species and facilitate NEOs subcellular diffusion and accumulation. The conserved transport function was further demonstrated by Xenopus laevis oocyte and yeast assay. BraPIP1;1 and BraPIP2;1 gene knockouts and interaction assays suggested that they can form functional heterotetramers. Further assessment of the potential of mean force (PMFs) indicated a negative correlation between that NEOs uptake and energy barrier of BraPIP1;1 channels. This study shows that aquaporins transport organic compounds with greater osmolarity than previously thought, providing new insight into the molecular mechanisms of organic compound uptake and facilitating the innovation of systemic pesticides.