Analysis of α-linolenic acid metabolism in 'Fengtang' plum across different maturity stages

• `Fengtang' plum, a distinctive local variety originating from Guizhou, is acclaimed for its pronounced fruit aroma and superior sweetness. • This study constitutes the first comprehensive investigation into the metabolic dynamics of alpha-linolenic acid in 'Fengtang' plum across different stages of maturity. • The results of this research provide a solid theoretical foundation for the cultivation and management practices of 'Fengtang' plum. • The concentration of α -linolenic acid in 'Fengtang' plum progressively accumulates throughout its developmental stages. The fruit of the 'Fengtang' plum exhibits a thin skin, is abundant in juice, and boasts a crisp yet refreshing texture. Notably, it is characterized by its substantial size, sweetness, and a honey-like flavor. This fruit is also a rich source of various nutrients. Linolenic acid metabolism not only influences cell membrane function but is also intricately linked to fruit ripening. This study employed 'Fengtang' plums as the experimental material to investigate the metabolic mechanisms of linolenic acid during the plum ripening process. Results showed that the L, a *, and b * values of `Fengtang' plum at different ripening stages gradually increased, with the a * value increasing by 205.72% and the b * value by 32.15% compared to the pre-color change stage. The fruits transitioned from dark green to golden yellow. Soluble solids content increased by 36.39% post-color change, while hardness decreased by 117.04% and titratable acidity decreased by 50%. Linolenic acid and linoleic acid levels progressively increased during ripening, whereas palmitic acid levels tended to decrease. Additionally, the activities of key enzymes in linolenic acid metabolism, including lipoxygenase (LOX), allene oxide synthase (AOS), and allene oxide cyclase (AOC), were observed to increase. 31 genes are involved in α-linolenic acid metabolism, with their expression levels upregulated during fruit ripening. During fruit ripening, the expression levels of 31 genes involved in α -linolenic acid metabolism, including LOX, AOS, AOC, alcohol dehydrogenase (ADH), 12-oxophytodienoic acid reductase (OPR), acetyl-CoA acyltransferase (FadI), and chloroplastic oxoene reductase (CEQORH). Additionally, 11 lipid metabolites were upregulated while 9 were downregulated during fruit ripening. The α-linolenic acid metabolic pathway likely plays a significant role in the development of 'Fengtang' plum, suggesting potential impacts on fruit color, quality, and appearance.