Li Chao-Lin, Huang Min, Ge Na, Wang Qing-Yan, Jia Jin-Shan, Luo Ting, Zhang Jin-Yan, Zhou Ping, Chen Jun-Wen
College of Agronomy and Biotechnology, Yunnan Agricultural University Kunming 650201, China National & Local Joint Engineering Research Center on Germplasm Innovation & Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University Kunming 650201, China Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University Kunming 650201, China.
College of Agronomy and Biotechnology, Yunnan Agricultural University Kunming 650201, China.
Zhongguo Zhong Yao Za Zhi. 2025 Jun;50(12):3307-3321. doi: 10.19540/j.cnki.cjcmm.20250217.105.
Panax species are mostly valuable medicinal plants. While some species' seeds are sensitive to dehydration, the dehydration tolerance of seeds from other Panax species remains unclear. The phospholipase D(PLD) gene plays an important role in plant responses to dehydration stress. However, the characteristics of the PLD gene family and their mechanisms of response to dehydration stress in seeds of Panax species with different dehydration tolerances are not well understood. This study used seeds from eight Panax species to measure the germination rates and PLD activity after dehydration and to analyze the correlation between dehydration tolerance and seed traits. Bioinformatics analysis was also conducted to characterize the PnPLD and PvPLD gene families and to evaluate their expression patterns under dehydration stress. The dehydration tolerance of Panax seeds was ranked from high to low as follows: P. ginseng, P. zingiberensis, P. quinquefolius, P. vietnamensis var. fuscidiscus, P. japonicus var. angustifolius, P. japonicus, P. notoginseng, and P. stipuleanatus. A significant negative correlation was found between dehydration tolerance and seed shape(three-dimensional variance), with flatter seeds exhibiting stronger dehydration tolerance(r=-0.792). Eighteen and nineteen PLD members were identified in P. notoginseng and P. vietnamensis var. fuscidiscus, respectively. These members were classified into five isoforms: α, β, γ, δ, and ζ. The gene structures, subcellular localization, physicochemical properties, and other characteristics of PnPLD and PvPLD were similar. Both promoters contained regulatory elements associated with plant growth and development, hormone responses, and both abiotic and biotic stress. During dehydration, the PLD enzyme activity in P. notoginseng seeds gradually increased as the water content decreased, whereas in P. vietnamensis var. fuscidiscus, PLD activity first decreased and then increased. The expression of PLDα and PLDδ in P. notoginseng seeds initially increased and then decreased, whereas in P. vietnamensis var. fuscidiscus, the expression of PLDα and PLDδ consistently decreased. In conclusion, the dehydration tolerance of Panax seeds showed a significant negative correlation with seed shape. The dehydration tolerance in P. vietnamensis var. fuscidiscus and dehydration sensitivity of P. notoginseng seeds may be related to differences in PLD enzyme activity and the expression of PLDα and PLDδ genes. This study provided the first systematic comparison of dehydration tolerance in Panax seeds and analyzed the causes of tolerance differences and the optimal water content for long-term storage at ultra-low temperatures, thus providing a theoretical basis for the short-term and ultra-low temperature long-term storage of medicinal plant seeds with varying dehydration tolerances.
人参属植物大多是珍贵的药用植物。虽然一些物种的种子对脱水敏感，但其他参属物种种子的脱水耐受性仍不清楚。磷脂酶D（PLD）基因在植物对脱水胁迫的响应中起重要作用。然而，不同脱水耐受性的人参属植物种子中PLD基因家族的特征及其对脱水胁迫的响应机制尚不清楚。本研究以8种人参属植物的种子为材料，测定脱水后种子的发芽率和PLD活性，分析脱水耐受性与种子性状之间的相关性。还进行了生物信息学分析，以鉴定三七（PnPLD）和越南人参变种屏边三七（PvPLD）的基因家族，并评估它们在脱水胁迫下的表达模式。人参种子的脱水耐受性从高到低依次为：人参、姜状三七、西洋参、越南人参变种屏边三七、狭叶竹节参、竹节参、三七、屏边三七。脱水耐受性与种子形状（三维方差）之间存在显著负相关，种子越扁平，脱水耐受性越强（r=-0.792）。在三七和越南人参变种屏边三七中分别鉴定出18个和19个PLD成员。这些成员分为5种亚型：α、β、γ、δ和ζ。三七和越南人参变种屏边三七的基因结构、亚细胞定位、理化性质等特征相似。两个启动子都含有与植物生长发育、激素反应以及非生物和生物胁迫相关的调控元件。脱水过程中，三七种子中的PLD酶活性随着含水量的降低而逐渐增加，而越南人参变种屏边三七中的PLD活性则先降低后增加。三七种子中PLDα和PLDδ的表达先增加后降低，而越南人参变种屏边三七中PLDα和PLDδ的表达则持续降低。综上所述，人参种子的脱水耐受性与种子形状呈显著负相关。越南人参变种屏边三七的脱水耐受性和三七种子的脱水敏感性可能与PLD酶活性以及PLDα和PLDδ基因的表达差异有关。本研究首次对人参种子的脱水耐受性进行了系统比较，分析了耐受性差异的原因以及超低温长期保存的最佳含水量，从而为不同脱水耐受性的药用植物种子的短期和超低温长期保存提供了理论依据。
