温度胁迫对白桦悬浮细胞中三萜积累及防御酶活性的影响

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。

Effects of Temperature Stress on the Accumulating of Triterpenes and Defense Enzyme Activity in Suspension Cells of Birch (Betula platyphylla Suk.)

After 7-d-suspending-culture cells of Birch (Betula platyphylla Suk.) which were treated with two kinds of temperature stress: the high (50 ℃ for 1h) and low temperature (4℃ for 3h),respectively, they were continuously suspended culture for 0 h～7d, and during that time, the growth, accumulation of total triterpenes and oleanolic acid, and the activities of defense enzyme were investigated. The results showed that: for the total triterpenes, its accumulation significantly increased in the cells suspending-cultured for 24～3d after both the high and low temperature treatments; it was higher in these cells treated with high temperature than low temperature; and its highest was in the cells suspending for 48 h after high temperature treatment, higher 36.4% and 12.87% than those after control(25℃) and low temperature treatment, respectively. The accumulation of total triterpenes in the 4d～7d suspending-culture cells after low temperature treatment, also obviously increased, and higher 22.1% in the 7-d suspending-culture cells than that in control. For the oleanolic acid, its accumulation in the cells suspending-culutre for 15h～4 d was significantly improved after both the high and low temperature treatments, and they in the cells suspending-culture after high and low temperature treatments were higher 38.1% and 39.65% than control, respectively. The activities of defense enzyme: SOD, CAT, PAL and POD in the cells treated with the high and low temperature, were accelerated, and the accumulation of MDA (malondialdehyde) was higher. But their activities changes were different. Those results suggested that the interaction of these defense enzymes in cells relieved the free radical hurts, which made cells adapt to tremperature stress, and promote the secondary metabolism materials.