Visualization of Stress-Induced Dynamic Ethylene in AOX1A Transgenic Using a Fluorescent Lifetime Probe

Ethylene, as a crucial plant hormone, plays a significant role in regulating plant growth, development, and stress responses. In this study, we developed a novel two-photon fluorescent probe, ETP, based on a naphthalene fluorophore, to detect ethylene fluctuations in plants with high sensitivity and specificity. Experimental results demonstrated that ETP could efficiently penetrate plant cells, exhibiting a marked increase in the fluorescence intensity corresponding to rising ethylene levels. Given that AOX1A (Alternative Oxidase 1A), a key component of the ethylene signaling pathway, enhances ethylene sensitivity, we applied ETP for ethylene imaging in both wild-type and AOX1A transgenic Arabidopsis (AOX1A overexpressor). Following ACC treatment, the mutant plants exhibited significantly higher ethylene production than the wild type, and ETP successfully visualized these differences. Furthermore, fluorescence lifetime imaging experiments confirmed the robust capability of ETP in detecting ethylene variations. As an innovative fluorescent probe, ETP provides a powerful tool for investigating ethylene signaling pathways and deepening our understanding of ethylene's role in plant growth, development, and stress responses.