Tree peony (Paeonia rockii) is an excellent woody oilseed crop, known for its high α-linolenic acid (ALA, ~45%) content, which is of great value for human health. However, the mechanisms underlying this high-level ALA accumulation in tree peony seeds are poorly understood. In this study, we evaluated the dynamic changes in the lipidomic profile of P. rockii seeds during development. A total of 760 lipid molecules were identified in P. rockii seeds; triacylglycerol (TAG) lipid molecules showed the highest abundance and diversity, both increasing during seed development. Particularly, ALA was the predominant fatty acid at the TAG sn-3 position. We further characterized two diacylglycerol acyltransferase (DGAT) genes and three phospholipid:diacylglycerol acyltransferase (PDAT) genes involved in the transfer of fatty acids to the TAG sn-3 position. Gene expression and subcellular localization analyses suggested that PrDGATs and PrPDATs may function as endoplasmic reticulum-localized proteins in seed TAG biosynthesis. In vitro functional complementation analysis showed different substrate specificities, with PrPDAT2 having a specific preference for ALA. Multiple biological assays demonstrated that PrDGAT1, PrDGAT2, PrPDAT1-2, and PrPDAT2 promote oil synthesis. Specifically, PrPDAT2 leads to preferential ALA in the oil. Our findings provide novel functional evidence of the roles of PrDGAT1 and PrPDAT2, which are potential targets for increasing the ALA yield in tree peony and other oilseed crops.

Dendrobium chrysotoxum Lindl., an important medicinal plant, contains polysaccharides (DCP) as its principal bioactive components. This review systematically outlines recent advances in the extraction, purification, structural characteristics, biological activities, and future prospects of DCP. For extraction, conventional hot water extraction followed by ethanol precipitation remains common but is limited by high energy consumption and prolonged duration. Advanced techniques, such as enzyme‐assisted extraction (yielding 8.41% under optimized conditions) and a combined ultrasonic‐hot water method (achieving 20.41% purity), significantly enhance efficiency. Purification generally involves deproteinization, removal of low‐molecular‐weight impurities, and fractionation via column chromatography to obtain homogeneous polysaccharide fractions. Structurally, DCP are heteropolysaccharides primarily consisting of glucose and mannose in varying molar ratios, with molecular weights ranging from 10 ⁴ to 10 ⁶ Da. Their backbone is mainly composed of (1→4)‐linked Manp and Glcp residues, featuring branching and partial acetylation. Biologically, DCP exhibit a broad spectrum of activities, including antioxidant and anti‐aging effects, immunomodulation, and organ protection. Additionally, DCP show hypoglycemic and antitumor potential, inhibiting proliferation of SPC‐A‐1 and HeLa cells through apoptosis induction. Despite these findings, challenges remain including inefficient extraction and insufficient understanding of the structure–activity relationships and molecular mechanisms underlying DCP's diverse biological activities. Future research should prioritize innovative extraction technologies, optimized purification, in‐depth mechanistic investigations, and the development of practical applications.