病原菌Pst DC3000侵染拟南芥导致自噬和光合作用的抑制  

Autophagy and Declined Photosynthesis in Arabidopsis during Pathogenic Pst DC3000 Infection

作　　者：杨柳[1,2] 董浚键[1,2] 陈文利[1,2] 

机构地区：[1]华南师范大学生命科学学院广东省植物发育生物工程重点实验室,广州510631 [2]华南师范大学激光生命科学教育部重点实验室,广州510631

出　　处：《生物物理学报》2011年第6期517-527,共11页Acta Biophysica Sinica

基　　金：教育部长江学者和创新团队发展计划(IRT0829);"863"计划项目(2007AA10Z204);广东省科技攻关项目(2007A020300008-6);华南师范大学激光生命科学教育部重点实验室开放课题基金项目~~

摘　　要：在病原菌侵染下,植物体是如何通过超敏反应限制病原菌扩增的,到目前为止还不清楚。最近的研究显示自噬起了必要的作用,可见,研究自噬和超敏反应的机制非常重要。本研究通过观察在非寄主病原菌突变体丁香假单胞菌番茄致病变种(Pseudomonas syringae pv.tomatoDC3000,Pst DC3000)的侵染下,拟南芥光合功能的变化及自噬现象出现的情况,以为进一步研究植物抗病机理提供实验基础。以野生型拟南芥为材料,采用光谱分析和叶绿素荧光成像分析手段,研究不同浓度的Pst DC3000侵染对拟南芥离体叶片光合功能的影响;以转基因野生型拟南芥(绿色荧光蛋白标记的自噬基因8a)幼根为材料,应用共聚焦显微镜,研究不同浓度的Pst DC3000诱导拟南芥自噬的情况。实验发现,OD600=0.2的Pst DC3000侵染,可显著诱导拟南芥叶片活性氧的积累和迸发,并会引起拟南芥叶片光合作用效率的下降。同时发现,该病原菌处理2 h,可导致拟南芥根中自噬小体的产生。用2',7'-二氯二氢荧光素二乙酯(2',7'-dichlorodihydrofluorescein diacetate,H2DCFDA)标记活性氧,检测了Pst DC3000作用下叶片活性氧产生量的变化,发现,在OD600=0.2的Pst DC3000作用下,90 min内,叶片组织中的活性氧产生了明显的积累。以上结果说明:Pst DC3000侵染叶片,导致了活性氧迸发和光合系统的受损,进而推测这两个结果具有相关性;在植物与病原菌的互作系统中,光合系统的变化规律可以作为典型的指标来加以检测。How plants are able to restrict the hypersensitivity（HR） to cells in the immediate area surrounding an infection has,until now,been unclear.Recently,autophagy appears to be necessary for the spatial restriction of programmed cell death,it is very important to study the mechanism of autophagy and HR.Studying photosynthetic function and autophagy in Arabidopsis during infection by Pseudomonas syringae pv.tomato DC3000（Pst DC3000） has important implications in elucidating mechanisms of disease resistance.In this paper,wild type Arabidopsis thaliana（ecotype Columbia） was used to study changes in photosynthetic function in Arabidopsis leaves after infection by different concentrations of Pst DC3000,by measuring fluorescence spectra and chlorophyll fluorescence analysis.Young roots from transgenic Arabidopsis（green fluorescent protein tagged ATG8a,GFP-ATG8a） was also used to study autophagy induction by different concentrations of Pst DC3000,by laser scanning confocal microscopy.It was found that Arabidopsis thaliana infected by Pst DC3000（OD600=0.2） induced leaf oxidative burst and a decline in photosynthetic efficiency.Further,autophagic bodies were observed 2 h after infection of roots.The generation of active oxygen was also detected with the H2DCFDA（2＇,7＇-dichlorodihydrofluorescein diacetate） labeling infection by Pst DC3000 at OD600 of 0.2.There was an obvious accumulation of active oxygen along with the time under Pst DC3000 infection.From these data,it is concluded that infection by Pst DC3000 leads to the oxidative burst and the damage of photosystem,which may be related to eath other.And,in plant and pathogen interaction system,the changes of photosystem can be detected as typical indicators.

关 键 词：丁香假单胞菌番茄致病变种 拟南芥 光合功能 细胞自噬 活性氧 

分 类 号：Q945.78[生物学—植物学]