高温胁迫对金露梅叶片结构和生理代谢的影响

Effects of High Temperature Stress on Leaf Structures and Physiological Metabolism of Potentilla fruticosa L.

以3年生金露梅叶片为试材,在42℃下持续3d高温胁迫,研究了高温对其叶片叶绿体超微结构、叶绿素荧光参数、细胞膜透性、渗透物质含量、抗氧化酶活性的影响。结果表明:随着高温胁迫时间的延长,金露梅的叶绿体发生严重的解体现象;叶片最大光化学效率(Fv/Fm)呈下降趋势,非光化学猝灭系数(qN)和光化学猝灭系数(qP)先上升后下降。细胞膜透性及丙二醛(MDA)、游离脯氨酸、可溶性糖含量呈上升趋势,且显著高于对照(未进行高温胁迫);超氧化物歧化酶(SOD)活性无明显变化,过氧化氢酶(CAT)活性呈先上升后下降趋势。表明在持续高温胁迫下,金露梅叶片受到损伤,但植物体内会通过渗透物质及抗氧化酶来缓解高温伤害。

3-year-old Potentilla fruticosa L.was taken as material and treated at 42 ℃for 3 days.The effects of high temperature on chloroplast ultra-structures of leaf,chlorophyll fluorescence parameters,the membrane permetability,osmotic regulation substances and antioxidant enzyme activities of Potentilla fruticosa L.were studied.The results showed that with the extension of high temperature stress time,the chloroplast showed severe degradation and the maximal photochemical efficiency Fv/Fm reduced significantly,while the non-photochemical quenching(qN)and the photochemical quenching(qP)first rose then declined.The membrane permetability,the contents of MDA,free proline and soluble sugar increased gradually,and all the indicators were significantly higher than those of control(no high temperature stress).While the activity of SOD showed no obvious change,and the activity of CAT first rose and then declined.The leaves of P.fruticosa suffered seriously damaged with the high temperature stress,but the plant could relieve heat damage through osmotic regulation substances and antioxidant enzyme.