An AIE-based ratiometric fluorescent probe for highly selective detection of H 2 S in plant stress responses.

Hydrogen sulfide (H 2 S) has emerged as a crucial signaling molecule in plant stress responses, playing a significant role in regulating various physiological and biochemical processes. In this study, we report an aggregation-induced emission (AIE)-based ratiometric fluorescent probe TPN-H 2 S for the highly selective detection of H 2 S in plant tissues. The probe exhibited excellent sensitivity and selectivity towards H 2 S over other analytes, enabling real-time monitoring of H 2 S dynamics in living cell. Furthermore, the AIE-based ratiometric probe TPN-H 2 S allowed for accurate quantification of H 2 S levels, providing valuable insights into the spatiotemporal distribution of Cys metabolism produces H 2 S. Importantly, the physiological pathways and signaling mechanisms of H 2 S production of was investigated in plant tissues under Cr and nano-plastics stress. Utilizing a high-throughput screening approach, we identified exogenous substances such as calcium chloride (CaCl 2 ) and abscisic acid (ABA) that could induce higher level of H 2 S production during the stress response in plants. Overall, those findings demonstrate the potential of the AIE-based ratiometric fluorescent probe TPN-H 2 S as a powerful tool for unraveling the role of H 2 S in plant stress responses and pave the way for further exploration of H 2 S-mediated signaling pathways in plants.