目的 探索苗期低温胁迫对川续断Dipsacus asper生长发育及川续断皂苷VI含量积累的影响，为川续断种植生态调控奠定基础。方法 在5、10、15、25 ℃条件下处理川续断幼苗，测定川续断皂苷VI含量、农艺性状及抗逆性生理指标，筛选低温胁迫温度；将低温胁迫的不同种质川续断幼苗移栽至试验田种植18个月，动态测量生物量、川续断皂苷VI含量及川续断皂苷VI合成途径关键酶基因表达量。结果 10 ℃低温胁迫促进川续断幼苗中川续断皂苷VI含量升高，抑制川续断的生长，川续断幼苗中丙二醛（malondialdehyde，MDA）和超氧化物歧化酶（superoxide dismutase，SOD）活性显著升高；苗期低温胁迫对川续断的后期生长发育无显著影响，可持续促进川续断皂苷VI含量积累，其中低海拔地区川续断种质川续断皂苷VI含量积累增加最为显著；苗期低温胁迫促进川续断皂苷VI合成途径关键酶基因DaAACT、DaHMGCR、DaHMGS、DaP450、DaSQE、DaUGTs在不同时期显著上调表达。结论 适度苗期低温胁迫可上调川续断后期生长川续断皂苷VI合成途径基因的表达，促进川续断皂苷VI积累，且对川续断生长发育无显著影响。

Objective To investigate the impact of early low temperature stress at seedling stage on the growth, development, and accumulation of asperosaponin VI in Dipsacus asper, with the objective of establishing a foundation for ecological regulation in D.asper cultivation. Methods D. asper seedlings were subjected to different temperatures (5, 10, 15, and 25 ℃) to assess the content of asperosaponin VI, agronomic traits, and physiological indicators associated with stress resistance, and screen the low-temperature stress temperature. Various germplasms of D. asper seedlings exposed to low temperature stress were transplanted into experimental fields for an 18-month period. Biomass, content of asperosaponin VI, and expression levels of key enzyme genes involved in its synthesis pathway were dynamically measured. Results Exposuring to low temperature stress of 10 ℃ promotes the accumulation of asperosaponin VI and inhibits the growth of D. asper seedlings. The activities of malondialdehyde (MDA) and superoxide dismutase (SOD) in D. asper seedlings significantly increase under low temperature stress. Low temperature stress during the seedling stage does not have a significant impact on the subsequent growth and development of D. asper. However, it consistently enhances the accumulation of asperosaponin VI, with the most pronounced increase observed in low-altitude regions. Key enzyme genes DaAACT, DaHMGCR, DaHMGS, DaP450, DaSQE, and DaUGTs involved in the synthesis pathway of asperosaponin VI are significantly upregulated at different stages under low temperature stress during the seedling stage. Conclusion Moderate low-temperature stress during the seedling stage induces upregulation of genes involved in the biosynthetic pathway of asperosaponin VI in D. asper, thereby enhancing its accumulation, while exerting negligible effects on growth and development of D. asper.

R286.2

国家重点研发计划（2023YFC3503803）；国家自然科学基金项目（82160725）