Effects of elicitors on the expression of secoiridoid pathway genes and metabolite accumulation in Gentiana macrophylla
摘要
Secoiridoids, the predominant secondary metabolites of Gentiana species, are extensively utilized in the pharmaceutical industry. This study investigated the effects of AgNO3 (Ag+, 0.92 mM), CuSO4 (Cu2+, 200 µM), arachidonic acid (AA, 10 mg/L), and salicylic acid (SA, 200 µM) on the accumulation of the three principal secoiridoid compounds in G. macrophylla. Loganic acid accumulation was significantly enhanced by AA (12.33 ± 1.91 mg/g), followed by SA (11.12 ± 0.77 mg/g) and Ag+ (8.18 ± 0.01 mg/g). SA notably increased swertiamarin content (20.88 ± 0.78 mg/g), followed by AA (6.73 ± 1.57 mg/g) and Ag+ (5.13 ± 0.004 mg/g). The accumulation of gentiopicroside was elevated by all four elicitors, with Ag+ inducing the highest increase, reaching 168.14 ± 0.41 mg/g on the third day. Key enzyme genes in metabolic pathways exhibited the strongest response to Ag+. Under the influence of Ag+, the expression of DXS, CMK, MCS, HDS, and HDR in the MEP pathway, HMGR and PMK in the MVA pathway, and GPPS and SLS in the secoiridoid pathway were significantly elevated in the roots and leaves. Canonical correlation analysis (CCA) indicated a significant association between metabolic pathway genes and metabolites. These results suggest that the synthesis and accumulation of loganic acid, swertiamarin, and gentiopicroside in G. macrophylla may be modulated in response to various elicitors. These findings provide a foundation for further research into the regulatory mechanisms governing plant responses to elicitors.