Biochemical and gene expression analyses character volatile compounds, fatty acids, and physiochemical properties of Stauntonia obovatifoliola seed oil.

Stauntonia obovatifoliola subsp. urophylla is a promising oilseed crop. This study first systematically evaluated its seed oil including physicochemical properties, fatty acid profile, and volatile compounds, and genes related to carotenoid and fatty acid biosynthesis. The oil had high carotenoid content (77.49 ± 1.11 mg/100 g), moderate iodine value (82.91 ± 2.86 g/100 g), low acid and peroxide values, and antioxidant/antimicrobial activities. Mature seeds contained unsaturated fatty acids (UFAs, 66.68 %), mainly oleic acid (30.93 %) and linoleic acid (21.00 %). A distinctive C19:1N9T component was also detected. Twenty-eight volatile compounds including eight terpenes, eight alkanes, five alcohols, five arenes and two aldehydes. Notably, during rapid oil accumulation phase (July to August), fatty acid biosynthesis genes were elevated, whereas carotenoid synthesis genes were suppressed, suggesting substrate competition. These findings offer help in purposefully exploitation and utilization of S. obovatifoliola seeds oil in food, cosmetics and pharmaceuticals.