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.