烟草感染丛枝病后的生理生化变化初步研究Ⅰ

Preliminary Studies on Biochemical and Physiological Changes of Tobacco Infected by Witches'broom Disease(I)

烟草感染丛枝病病原后表现为典型的矮化丛枝症状．供试烟草品种Ｋ３２６以烟蚜为媒介，成功接种丛枝病病原后，分析病株与健株中与生长素（ＩＡＡ）代谢相关的锌元素含量；ＩＡＡ氧化、过氧化物酶的活性及同功酶变化，同时对抗感病相关的苯丙烷代谢关键酶苯丙氨酸氨裂解酶（ＰＡＬ）和植株解除Ｈ２Ｏ２毒害相关的过氧化氢酶活性进行测定．结果表明：感病烟株代谢发生了显著的变化，病株中锌含量降低、ＩＡＡ氧化及过氧化物酶活性增强且在聚丙烯酰胺凝胶电泳图谱上它们的同功酶谱带多于健株，ＰＡＬ的活性随接种时间的延长先升后降；过氧化氢酶的活性显著下降．另据测定，病株叶绿素含量减少而可溶性糖含量增高．

Tobacco witches' broom disease could cause characteristic dwarf and witches' broom symptom on Tobacco. By aphides as vector transmmiting the pathogen ,the tobacco (Nicotiana tabacum cv.K 326 ) was infected successfully.With these plant samples and their controls, zinc content、Indole 3-Acetic Acid oxidase (IAAoxidase)、Peroxidase and their isozymes were analysed.The activity of Phenylalanine Amino Lysase(PAL) and Catalase were determined. Compared with healthy controls, the results showed that the amount of zinc was reduced.the IAAoxidase and peroxidase activity were promoted and moreover,there were more isozymes' tracks on Polyacrylamide gel plates.The Catalase's activity decreased.PAL's activity increased at the beginning of infection,but declined with prolongation of the infected time. Analysis of the content of cholorophyll and the total amount of soluble sugar proved that the former decreased in infected tissues while the latter increased.