Real-Time Subcellular Imaging of Plant Signaling Molecules and Bio-Coronas by Near-Infrared Nanosensors.

Abstract

Chemical imaging at high spatiotemporal resolution is crucial for advancing plant sciences and biotechnology. We demonstrate optical nanosensors for subcellular imaging of signaling molecules (H₂O₂) and lipid corona formation in plant tissues at high spatial (<1 μm) and temporal resolution (1 s) in the tissue transparent near-infrared (nIR) window. Nanosensor fluorescence peak quenching (12-25%) over time revealed the rapid propagation (<30 s) of exogenous H₂O₂ waves (100 μM) from plant mesophyll to stomata and pavement cells. Ca²⁺ induced higher endogenous H₂O₂ in mesophyll cells, whereas organelle electron transport chain disruptors and salt stress generated similar H₂O₂ across all leaf cell types. Furthermore, the nanosensor quenching kinetics in photosynthetic mesophyll (0.018 s^-1) and epidermal (0.004 s^-1) cells enabled the detection of plant lipid corona formation. Optical nanosensors elucidate spatiotemporal dynamics of plant signaling molecules and advance our understanding of biocorona formation.