豆链格孢菌对白车轴草生理代谢及活性氧清除系统酶的影响

Effects of Alternaria azukiae on physiological metabolism and active oxygen eliminating enzyme activities of Trifolium repens

通过盆栽实验 ,研究了接种豆链格孢菌对白车轴草叶组织细胞膜透性、色素含量、丙二醛 (MDA)含量以及超氧化物歧化酶 (SOD)、过氧化物酶 (POD)和过氧化氢酶 (CAT)活性的影响 .结果表明 ,豆链格孢菌使白车轴草叶组织细胞膜透性上升 ,电导率显著升高 ,膜脂过氧化加强 ,MDA水平上升 ,色素含量下降 .电导率和MDA含量均与感病时间呈显著正相关 ,而色素含量与感病时间呈显著负相关 .豆链格孢菌刺激其寄主白车轴草叶片膜脂过氧化作用发生 ,积累大量的活性氧 ,使其超出防御酶的清除能力 ,致使活性氧清除系统遭到破坏 ,保护酶系统失衡 ,其中SOD和CAT活性显著下降 ,而POD活性明显上升 .接种1 2d后 ,SOD和CAT分别降低了 55 2 %和 37 8% ,而POD比对照升高约 1 6倍 .

A pot experiment was installed to study the effects of Alternaria azukiae inoculation on the cell membrane permeability,pigment and MDA contents,and activities of SOD,POD and CAT of Trifolium repens .The results showed that A.azukiae infection made T.repens leaf tissue increase its cell membrane permeability,electric conductivity,over oxidation and MDA content,but decrease its pigment content.The electric conductivity and MDA content were positively related with infection time,whereas the pigment content was negatively related with it.Due to the stimulation by A.azukiae ,the over oxidation of cell membrane was intensified,which resulted in a large amount of active oxygen accumulated and beyond the defense ability,the active oxygen metabolism system was destroyed,and the balance of protective enzyme system was broken.After 12 days of A.azukiae inoculation,the activities of SOD and CAT decreased by 55.2% and 37.8%,respectively,while the POD activity increased by 1.6 times.