目的 分析真菌诱导的白桦悬浮体系中N、P的吸收利用和三萜合成的关系。方法 在白桦悬浮细胞的生长末期添加40 μg/mL真菌诱导子，采用比色法分析真菌诱导后白桦悬浮体系中N、P和三萜量的变化。结果 白桦细胞的干质量、三萜量和产量随着真菌处理时间的延长表现为逐渐降低趋势。其中，三萜量和产量均于真菌诱导后第1天达到最高，分别为21.98 mg/g和123.82 g/L，约为对照的2倍；白桦悬浮体系的pH值和电导率在真菌诱导后第1天达到高峰，pH值增长了6.10%，电导率增加了8.20%；除细胞内磷酸根质量分数在诱导的第1、2天分别降低了28.67%、15.68%外，真菌诱导使白桦悬浮培养体系中硝酸根、铵根、磷酸根量基本呈增加趋势。进一步相关性分析发现，真菌诱导使胞外磷酸根、铵根和硝酸根质量分数与三萜量的相关性显著提高。结论 真菌诱导后白桦三萜合成的增加可能与磷酸根、硝酸根和铵根质量分数的变化相关。
Objective To analyze the relationship of N and P utilization and triterpene synthesis in birch (Betula platyphylla) suspension cell culture system induced by fungal elicitor. Methods Fungal elicitors (40 μg/mL) were added to the 8-day-old birch suspension cell culture, the change of N and P and triterpene content were analyzed by chemical colorimetry. Results The dry weight, triterpene content, and triterpene yield of birch cell decreased with the extension of fungal treatment time. Among them, triterpene content and yield were the highest after 1 d fungal induction, they were 21.98 mg/g and 123.82 g/L, respectively, about two times of the control. The pH value and conductivity of birch cell culture also reached a peak after 1 d fungal treatment with increase by 6.10% and 8.20%, respectively. The contents of nitrate, ammonium, and phosphate increased after fungal treatment, but the content of phosphate was reduced after day 1 and 2 induction by 28.67% and 15.68%. The correlations between phosphate, ammonium, nitrate and triterpenoid contents in birch cell medium were improved significantly after fungal treatment. Conclusion It is reasoned that increased synthesis of triterpenes after fungal elicitors inducement may be related to the concentration changes of phosphate, ammonium, and nitrate.