Single-nucleus RNA sequencing reveals a spatiotemporal pattern of H₂S signaling in Chinese cabbage

Plants rely on gasotransmitters like hydrogen sulfide (H₂S) to coordinate stress adaptation, yet how H₂S orchestrates spatiotemporal responses across cell types remains unknown. Here, we generated a high-resolution single-nucleus RNA sequencing (snRNA-seq) atlas of Chinese cabbage (Brassica rapa L. ssp. pekinensis) leaves, capturing the dynamic transcriptional response to H₂S over the course of 24 h. We identified 18 transcriptionally distinct clusters corresponding to nine major leaf cell types. H₂S induces globally coordinated transcriptional reprogramming, prominently featuring the broad activation of defense responses across cell types. We identified two H₂S-induced genes that enhance drought tolerance. BrHSP23.6, initially confined to guard cells, becomes globally expressed under H₂S fumigation and is required for H₂S-mediated enhancement of photosynthetic performance and drought tolerance. Similarly, BrNTF2, a de novo induced nuclear transport factor, is essential for H₂S-dependent stomatal regulation and drought resilience. In parallel, H₂S spatiotemporally activates hormone and sulfur metabolic pathways. Our study deciphers a spatiotemporal pattern of H₂S signaling at single-cell resolution, providing a new framework for understanding how gasotransmitters orchestrate plant adaptation.