Salicylic acid priming enhances seed germination in Apocynum venetum under salinity conditions

Salinity stress significantly impairs seed germination and seedling establishment in many economically valuable plant species. Salicylic acid (SA) is a key signaling molecule implicated in plant stress responses. Despite this, a significant knowledge gap remains regarding its concentration-dependent effects on Chinese hemp ( A. venetum ), a species recognized for its considerable ecological and pharmaceutical importance. In this study, we investigated the effects of seeds priming with SA on seed germination, osmolytes (soluble sugar and protein contents), antioxidant enzyme activities, and lipid peroxidation (malondialdehyde content). Seed priming with 0.3 mM SA alleviated the adverse effects under salt stress on seed germination and seedling growth. Seeds of A. venetum primed with 0.3 mM SA exhibited improved germination count, radicle length, embryo growth, germination potential, chlorophyll content, soluble sugar and protein contents, enhanced the activities of superoxide dismutase, peroxidase, and catalase, and decreased malonaldehyde content in the seeds. These results suggest that seed priming with SA enhances the accumulation of key osmolytes and photosynthetic pigments, and boosts antioxidant enzyme activities, thereby alleviating the adverse effects of salt stress on seed germination and seedling growth in A. venetum .