黄芩对干旱复水的生理生态响应

Physiological ecology responses of Scutellaria baicalensis to drought and rewatering

为探讨黄芩对短期干旱复水的生理生态响应。测定分析不同水分处理黄芩短期干旱复水期间叶片光合作用和叶绿素荧光参数、根中保护酶及黄酮合成关键酶活性等生理生化表征指标及根中黄芩苷、黄芩素积累的动态变化。结果显示,随干旱加剧各处理黄芩P n,T r,G s,F v/F m下降,F o升高;处理Ⅰ,Ⅱ黄芩根中SOD,POD活性对干旱响应比处理Ⅲ黄芩早;各处理黄芩的黄芩苷积累响应时间和增加幅度存在差异。复水后黄芩各指标有所恢复。因此,干旱导致土壤含水量降低,黄芩光合作用发生改变,破坏了抗氧化代谢平衡。黄芩启动自身防御机制,SOD,POD等保护酶,PAL,C4H等黄酮类代谢关键酶以及黄芩苷,黄芩素等黄酮类化合物协同作用,减少活性氧对细胞的伤害。

To Study the physiological ecology responses of Scutellaria baicalensis to drought and rewatering of short period, we tested and analyzed photosynthesis and chlorophyll fluorescence parameters of S. baicalensis leaves processed by different ways of water treatment in drought and rewatering period, characteristic indexes of physiology and biochemistry of root SOD, POD, PAL, C4H, etc. and accumulation dynamic change of root baicalin and baicalein. The result showed that along with the worsening drought, Pn, Tr, G~ and Fv/F~ of S. baicalensis dechned in different water supply, and Fo increased. The response of SOD and POD＇s activity in S. ba- icalertsis root to drought in I and II was earlier than it in Ill. The response time and increase range of baicalin accumulation existed differences in different water supply, and the indexes regained after rewatering. Therefore, photosynthesis of S. baicalensis changed and it destroyed the antioxidant metabolism balance when soil water content decreased resulting from drought. The synergistic effect of de- fence mechanism launched by S. baicalensis, SOD, POD, PAL, CAH, baicalin and baicalein reduced active oxygen＇s damage to the cell.