外源亚精胺对甜瓜幼苗白粉病抗性的影响  

Study on Exogenous Spermidine Improving Resistance to Powdery Mildew in Melon Seedlings

作　　者：李小玲[1] 刘长命[2] 刘炼红[1] 杨瑞平[1] 郑俊鶱[1] 莫言玲[1] 吴梅梅[1] 张显[1] 

机构地区：[1]西北农林科技大学园艺学院,陕西杨凌712100 [2]商洛学院,陕西商洛726000

出　　处：《西北植物学报》2015年第9期1800-1807,共8页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金(K305021310);国家西甜瓜产业技术体系水分管理与旱作栽培岗位科学家项目(CARS-26-18)

摘　　要：以高感白粉病甜瓜‘066’、感病品种‘0544’、抗病品种‘Yuntian-930’为试材,对白粉病菌胁迫下外源亚精胺(Spd)处理的甜瓜幼苗叶片超氧化物岐化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和多酚氧化酶(PPO)活性,以及过氧化氢(H2O2)、丙二醛(MDA)和光合色素含量进行了研究,探讨外源Spd对甜瓜白粉病抗性的诱导效应及其生理机制。结果表明:(1)白粉病菌接种后甜瓜叶片的防御酶活性、光合色素含量先升后降,MDA含量升高;(2)外源Spd处理缓解了白粉病菌胁迫下甜瓜叶片防御酶活性、光合色素含量的下降,降低MDA含量及甜瓜的病情指数,并以1.0mmol/L Spd处理效果最佳;(3)外源Spd处理使甜瓜叶片产生了更多的H2O2;(4)外源Spd提高甜瓜对白粉病抗性具有一定广谱性,且可向上传导。研究认为,H2O2可能参与白粉病胁迫下信号的传递,外源Spd可通过缓解白粉病菌胁迫下甜瓜防御酶活性和光合色素含量的下降来诱导甜瓜对白粉病的抗性。To gain further understanding about the physiological and biochemical effects of Spd,we conducted the effect of spermidine（Spd）on induced resistance to powdery mildew in susceptible Cucumis melon variety ‘066＇,‘0544＇and resistance variety ‘Yuntian-930＇seedlings.The activities of superoxide dismutase（SOD）,peroxidase（POD）,catalase（CAT）,polyphenol oxidase（PPO）,as well as chlorophyll a,chlorophyll b,total chlorophyll,carotenoid,hydrogen peroxide（H2O2）and malondialdehyde（MDA）contents were assayed in melon leaves after treated with Spd and inoculated with powdery mildew.The results show that：（1）the activities of four defense enzymes and the contents of photosynthetic pigments in melon leaves inoculated with powdery mildew were all raised at first,and then decreased.Furthermore,the content of MDA increased observably.（2）Spd mitigated the reduction of defense enzymes and the contents of photosynthetic pigments,and reduced the content of MDA and the disease index,and 1.0mmol/L Spd had the best effects.（3）Foliar-spraying Spd made the content of H2O2 in melon leaves go up whether if inoculated powdery mildew or not.（4）Exogenous Spd had a wide spectrum on improving resistance to powdery mildew and the resistance could conduct upward.One idea is that H2O2 may act as a kind of transport signals for the induction resistance to powdery mildew by Spd in melon.In summary,the results indicated that Spd mitigate the powdery mildew stress which cause reduction of defense enzymes activities and photosyn-thetic pigment contents,increase plants photosynthetic capacity,and decrease disease index observably,then increase melon resistance to powdery mildew.

关 键 词：亚精胺 甜瓜 白粉病菌 防御酶 光合色素 

分 类 号：Q945.78[生物学—植物学]