Ginsenosides, the principal bioactive triterpenoid saponins of Panax ginseng C.A. Meyer, accumulate abundantly in leaves. They form a large family of secondary metabolites comprising more than 300 structurally distinct compounds, yet how leaf senescence reshapes their accumulation remains unclear. We profiled 376 saponin metabolite features across four sampling stages spanning the natural senescence progression (T1–T3) and a frost-terminated stage (T4) by ultra-performance liquid chromatography–high-resolution mass spectrometry (UPLC-HRMS), modeled temporal effects across the natural senescence gradient (T1–T3) with generalized estimating equations (GEE), analyzed the frost-terminated stage T4 as a distinct endpoint, verified senescence histologically, and analyzed stage T1–T3 transcriptomes with replicate-based statistical testing. Leaf senescence globally reshaped the saponin metabolome, with 326 of the 376 saponin features (86.7%) showing significant temporal effects across the natural senescence gradient (T1–T3). The four classical aglycone classes—protopanaxadiol (PPD), protopanaxatriol (PPT), ocotillol (OT) and oleanolic acid (OA)—followed divergent accumulation programs across the natural senescence progression (T1–T3): sustained accumulation (PPT, OT and PPD) versus a U-shaped curve (OA). At the frost-terminated stage, T4, the classes diverged sharply—PPD-type abundance fell back to the T1 level (abundance-weighted class-level T4/T3 = 0.63), whereas the other classes rose further—a frost-associated remodeling pattern rather than a continuation of the senescence program. The frost-associated PPD decline was glycosylation-dependent—low-glycosylation compounds fell far more sharply than highly glycosylated ones (median of per-compound ratios T4/T3 0.51 vs. 1.04; one-sided permutation p = 1.2 × 10⁻⁴)—and coincided with T3 induction of β-glucosidase genes (exploratory and hypothesis-level, based on two qualified T3 replicates, and requiring validation with larger replicate numbers) and histologically verified vacuolar collapse, consistent with a deglycosylation-associated catabolic mechanism. Senescence signaling was consistent with differential hormone responses (salicylic acid activation, jasmonate and ethylene attenuation), broad suppression of Ca²⁺-signaling components and WRKY/NAC-centered transcriptional control, and joint analysis suggested a dichotomous saponin–gene correlation pattern. Collectively, these results establish a temporal atlas of ginsenoside accumulation during ginseng leaf senescence, delineate the class-specific coupling of saponin secondary metabolism to the senescence program, and offer a new perspective on ginsenosides as metabolites embedded in the physiological activities of the ginseng life cycle.

American ginseng (Panax quinquefolius L.) is an important medicinal crop, but its improvement in China is limited by variety degeneration and a shortage of elite cultivars. In this study, phenotypic traits and simple sequence repeat (SSR) markers were integrated to evaluate the genetic diversity of 51 selected accessions from major Chinese production regions. Phenotypic analysis showed that five of the 18 quantitative traits had phenotypic coefficients of variation exceeding 40%, mainly involving root traits such as fresh root weight and lateral root number. Broad-sense heritability for these root traits ranged from 61.70% to 74.80%, indicating substantial genetic contribution under standardized conditions. Principal component analysis identified five candidate elite accessions: CY3 and KD1 for tall stature and high yield, DH1 and LH2 for high ginsenoside content, and AT1 for well-developed lateral roots. A 12-accession representative subset was further proposed for conservation and pre-breeding. SSR-based clustering showed weak geographic differentiation, and Mantel analysis revealed no significant correlation between phenotypic and SSR-based genetic distances. These materials, together with the proposed accession-level conservation strategy, provide useful resources for germplasm preservation, parental selection, QTL mapping, and marker-assisted breeding.

Triploid Atractylodes chinensis (DC.) Koidz. (A. chinensis) is a valuable genetic resource for medicinal plant breeding, and there is a demand to develop an efficient in vitro regeneration protocol to resolve triploid sterility in production. In this study, the effects of sterilization, bud type, 6-benzyladenine (6-BA) combined with 1-naphthaleneacetic acid (NAA) or indole-3-butyric acid (IBA) and transplanting materials on shoot regeneration, rooting and growth were explored. The genetic stability of regenerated plants was verified using flow cytometry (FCM) and simple sequence repetition (SSR) molecular markers. When axillary buds were sterilized with sodium hypochlorite for 30 min and cultured on Murashige and Skoog (MS) + 1.5 mg·L^-1 6-BA + 0.4 mg·L^-1 NAA medium, the regeneration rate was 61.33%. Strong roots occurred on 1/2 MS combined with 3% sucrose and 0.6 mg·L^-1 IBA medium. Rooting plantlets transplanted into a mixture of peat soil: perlite (1:1, v/v), the survival rate up to 90.00%. Histological analyses revealed that shoot meristematic cells derived from cambium cells developed into the apical meristem and formed shoots. FCM analysis determined that the ploidy levels of 20 random regenerated plants were coincident with explants, the number and size of bands obtained by 6 pairs of SSR polymorphic primers were consistent. The results of this study show that our in vitro adventitious regeneration and plantlet transplantation protocol of triploid A. chinensis was efficient and produced strong genetic stability.