干旱胁迫对6种野生耐旱花卉幼苗根系保护酶活性及脂质过氧化作用的影响

从燕山东段野生花卉中筛选出6种耐旱的野生花卉,它们的耐旱性依次是叶底珠>栓翅卫矛>木半夏>孩儿拳头>南蛇藤>蚂蚱腿子,研究干旱胁迫至枯死临界点过程中其幼苗根系保护酶活性及脂质过氧化作用与耐旱性的关系.结果表明:在这一过程中各幼苗根系的MDA含量和保护酶活性的变化具有多样性的特点,其中叶底珠、孩儿拳头和栓翅卫矛根系的MDA含量具有明显的升降起伏,而南蛇藤、木半夏和蚂蚱腿子根系的MDA含量是呈缓慢上升的趋势;保护酶活性的升降起伏过程在各幼苗各有特点;叶底珠、栓翅卫矛、孩儿拳头和木半夏的POD同工酶都增加了特异谱带,南蛇藤的POD谱带没有变化,蚂蚱腿子POD 谱带部分消失.MDA含量及POD与SOD活性和耐旱性关系不明显,而POD同工酶有特异谱带增加的种类耐旱性较强.

Effect of Drought Stress on Activities of Cell Defense Enzymes and Membrane Lipid Peroxidation of the Roots of Six Wild Flowers in the Eastern Section of Yanshan Mountain

Six woody wild flowers which had high drought-tolerance were selected among the wild flower resources in the east section of Yanshan Mountain.The drought-tolerance of the species was in order of Securinega suffruticosa>Euonymus phellomanus>Elaeagnus multiflora>Grewia biloba var.parviflora>Celastrus orbiculatus>Myripnois dioica.The relationship between the drought resistance and the activities of cell defense enzymes and membrane lipid peroxidation of the roots were studied under the drought stress.The results showed that MDA content and the activities of cell defense enzymes in roots were various in response to drought stress.The MDA contents of Securinega suffruticora,Grewia biloba var.parviflora and Euonymus phellomanus increased at first,and then decreased,and the increase was before the point of wilting,while those of Celastrus orbiculatus,Elaeagnus multiflora and Myripnois dioica gradually increased under the drought stress.Dynamics of the activities of cell defense enzymes varied in the six flowers.In response to drought stress,extra bands of POD isoenzymes presented in Securinega suffruticosa,Euonymus phellomanus,Grewia biloba var.parviflora and Elaeagnus multiflora;some bands of POD isoenzymes diminished in Myripnois dioica;and the bands of POD isoenzymes remained unchanged in Celastrus orbiculatus.The results showed that the MDA content,activities of POD and SOD did not obviously relate to the drought resistance.The species that presented extra bands of isoenzymes had the ability to resist drought stress.