Intraspecific communication through volatile organic compounds in the mosses Didymodon vinealis and Syntrichia caninervis from an arid temperate desert

Background and Amis Volatile organic compounds (VOCs) mediated plant-plant communication is a crucial mechanism enhancing plants’ ecological fitness, yet its role in desert mosses remains unclear. Methods We analyzed VOCs emission from Didymodon vinealis and Syntrichia caninervis and simulated their intraspecific airborne communication under dehydration-rehydration cycles. The VOCs emitters and receivers were subsequently subjected to light rainfall events, and soluble sugar, starch, chlorophyll, and superoxide dismutase activity (SOD) were measured to assess stress resistance. Results Gas chromatography-mass spectrometry identified 333 compounds, including isoprene, terpenes, ketones, and aromatic hydrocarbons, whose emission profiles varied significantly with precipitation changes. Upon perceiving altered VOCs signals the two mosses species exhibited distinct physiological responses. D. vinealis-receivers showed higher soluble sugar and non-structure carbon (NSC) content than emitters and controls (CK, receivers that exposed to VOCs released by emitters that had not undergone hydration-dehydration cycles), whereas S. caninervis-receivers demonstrated increased NSC levels but no significant differences in soluble sugar or SOD activity compared to emitters. Both species maintained these enhanced physiological traits for 1∼7 days following 0mm rainfall conditions. Under single light rainfall event, D. vinealis-receivers exhibited higher NSC content or SOD activity across 0-1mm rainfall events, while S. caninervis-receivers only showed elevated SOD activity only under 0 and 0.2 mm rainfall. Conclusion Our findings demonstrate that VOCs mediate intraspecific communication in desert mosses and enhance physiological resilience to fluctuating hydration, providing new insight into their adaptive strategies and evolutionary trajectories in arid ecosystems.