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以白桦悬浮培养细胞为试材,悬浮培养第7d进行高温(50℃热处理1h)和低温(4℃冷胁迫3h)胁迫处理,此后不同时间(0h～7d)收获白桦细胞,研究细胞干重、三萜积累及防御酶活性的变化。研究结果表明,高温和低温胁迫后均表现在24h～3d收获细胞显著促进了白桦总三萜的合成,且以高温处理效果最佳,48h收获细胞时分别比对照(25℃)和冷胁迫处理提高36.4%和12.87%;而在冷胁迫处理后4d～7d表现显著刺激了总三萜的合成,其中在第7d总三萜的含量比对照增加了22.1%,且两温度胁迫处理后15h～4d显著促进了齐墩果酸三萜的积累,24h收获时,热处理和冷胁迫均比对照提高38.1%和39.65%。两温度胁迫后不同程度促进了超氧化物岐化酶(SOD)、过氧化氢酶(CAT)、苯丙氨酸裂解酶(PAL)、过氧化物酶(POD)活性提高及丙二醛的积累,但各酶活性出现高峰及变化规律存在差异,明确各酶相互协调、补充是保证细胞适应温度胁迫,减轻自由基伤害,并促进次生产物合成的原因。
The suspension culture cells of Betula platyphylla were used as experimental materials and treated with high temperature (50 ℃ heat treatment for 1 hour) and low temperature (4 ℃ cold stress for 3 hours) on the 7th day after suspension culture. After that, the white birch cells were harvested at different time (0h ~ 7d) Changes of Triterpene Accumulation and Defensive Enzyme Activity. The results showed that all the harvested cells at 24h ~ 3d enhanced the synthesis of total triterpene in birch, and the best treatment was at high temperature. After 48h harvest, the cells were harvested at 25 ℃ and cold stress respectively Increased by 36.4% and 12.87%, respectively. However, the synthesis of total triterpenes was significantly stimulated 4d ~ 7d after cold stress treatment, in which the content of total triterpenes increased by 22.1% compared with the control at the 7th day, 4d significantly promoted the accumulation of oleanolic acid triterpenoids, 24h harvest heat treatment and cold stress than the control increased by 38.1% and 39.65%. After two temperature stress, the activities of superoxide dismutase (SOD), catalase (CAT), phenylalanine lyase (PAL) and peroxidase (POD) Accumulation, but the peak of each enzyme activity and changes in the law there is a difference, a clear coordination of each enzyme, complement is to ensure that cells adapt to temperature stress, reduce free radical damage, and promote the synthesis of secondary products causes.