镰刀菌酸毒素对西瓜幼苗根细胞跨膜电位及叶细胞有关抗逆酶的抑制  

Inhibition of Root Cell Transmembrane Potential and Leaf Anti-Stress Enzymes of Watermelon Seedlings by Fusaric Acid

作　　者：吴洪生[1] 尹晓明[1] 刘东阳[1] 凌宁[1] 包蔚[1] 应蓉蓉[1] 朱毅勇[1] 郭世伟[1] 沈其荣[1] 

机构地区：[1]南京农业大学资源环境学院,南京210095

出　　处：《中国农业科学》2008年第9期2641-2650,共10页Scientia Agricultura Sinica

基　　金：国家"973"项目(2007CB109304);国家"863"项目(2006AAD10Z416);国家"十一五"科技支撑计划项目(2006BAD10B09);国家"948"项目(2006-G62和06-07-04B)

摘　　要：【目的】了解引起连作西瓜严重枯萎病的尖孢镰刀菌毒素对西瓜幼苗根和叶细胞有关生理功能的影响。【方法】用从尖孢镰刀菌西瓜专化型菌株提取的真菌毒素镰刀菌酸处理西瓜幼苗,考察其对细胞根系跨膜电位和叶片中相关抗逆酶的影响。【结果】高浓度镰刀菌酸处理西瓜幼苗12h后,根部细胞跨膜电位比对照下降61.9%～81.8%。不同浓度的毒素处理24h后,根系脱氢酶活性减少35.9%～90.9%。镰刀菌酸明显加速了叶片细胞膜脂质过氧化,24h后叶片丙二醛含量是对照的5.2～11.0倍。叶片中的苯丙氨酸解氨酶活性先增加,然后减少,6～12h活性最高,为对照的7.2～10.5倍。过氧化氢酶、超氧化物岐化酶、过氧化物酶也是先上升然后下降。过氧化氢酶活性在毒素处理3h后达到高峰,但再过3h后下降18.6%～52.5%。超氧化物岐化酶和过氧化物酶在毒素处理12h后达到最大,然后下降。叶片中的β-1,3-葡聚糖酶和几丁质酶在毒素处理后先快速上升,然后下降,最大活性分别出现在处理后12h和3h,分别是对照的10和15～30倍。【结论】镰刀菌酸强烈抑制了西瓜幼苗的根和叶细胞正常生理功能。破坏了叶片细胞的正常防卫系统和根细胞吸水和运输功能,引起细胞膜脂质过氧化生成大量的丙二醛,细胞结构遭受严重破坏,导致发病甚至细胞死亡。[ Objective ] Watermelon production is affected by wilt disease caused by Fusarium oxysporum f.sp. niveum （FON） in heavily infected continuously cultivated soil. [Method] The impact of fusaric acid （FA）, extracted from FON, on the transmembrane potential of roots cell and some anti-stress enzymes of leaf cells of watermelon seedlings was investigated. [ Result ] Results revealed that the potential at the highest concentration of FA in 12 h was decreased by 61.9%-81.8% compared with untreated controls. The dehydrogenase activity of root cells treated with different concentrations of FA in 24 h was reduced by 35.9%-90.9%. FA markedly accelerated the lipid peroxidase activity （LPO） of watermelon leaves. Malondiadehyde （MDA） in leaves in 24 h treated with different concentrations of FA was 5.2-11.0-fold as much as control. Phenylalanine ammonia-lyase activity （PAL） in leaves treated with FA was firstly increased and then decreased. The highest PAL activity was obtained after 6-12 h, which was 7.2-10.5-fold as much as control. Activities of catalase （CAT）, superoxide dismutase （SOD）, and peroxide （POD） were firstly increased and then decreased when the seedlings were treated with FA. Activity of CAT reached a peak 3 h after treatment with FA, but decreased after a further 3 h, declined by 18.6%-52.5%. The highest SOD and POD activities were observed after 12 h and then both declined. The [3-1,3-glucanase and chitinase activities in leaves treated with FA were firstly quickly increased and then declined, the highest activities were found after 12 h and 3 h, which were around 10-and 15-30-fold as much as untreated controls, respectively.[Conclusion] It is concluded that FA strongly inhibits root and leaf cells functions. FA destructs the leaf cell defense system of the watermelon seedlings and damages water uptake and transportation functions of root so that LPO is markedly stimulated to produce much more MDA, indicating severe injury of cell structure, thus leading to final disease and e

关 键 词：镰刀菌酸 细胞跨膜电位 丙氨酸解氨酶 还原氧系统 脂质过氧化 β-1 3-葡聚糖酶 几丁质酶 根系脱氢酶 西瓜 尖孢镰刀菌西瓜专化型 

分 类 号：S436.5[农业科学—农业昆虫与害虫防治]