三裂叶豚草锈菌侵染寄主叶片的显微和超微观察

Microscopic and ultramicroscopic investigation into the infection process of giant ragweed rust(Puccinia xanthii f.sp.ambrosiae-trifidae)

【背景】三裂叶豚草是我国重要的外来入侵植物之一,其传播速度快,已给我国造成巨大的经济损失。近年来发现的三裂叶豚草锈菌是一种对其具有生物防治潜力的病原菌。【方法】本文利用显微技术研究了三裂叶豚草锈菌的侵染过程及其对寄主结构的影响。【结果】三裂叶豚草锈菌菌丝可从多处侵入同一个叶肉细胞,胞间菌丝与叶肉细胞相接触可使部分细胞壁增厚。锈菌侵染使三裂叶豚草叶脉末梢导管分枝增多,造成三裂叶豚草水分代谢失调;叶片细胞内膜系统破碎化,细胞器结构受到不同程度的破坏,导致细胞内膜系统紊乱,细胞器结构稳定性降低。【结论与意义】豚草锈菌侵染破坏了三裂叶豚草叶片的细胞结构。本研究为深入研究豚草锈菌的致病机理奠定了基础。

[Background]Giant ragweed is one of main invasive plants in China and has caused great economic losses.The giant ragweed rust（Puccinia xanthi f.sp.ambrosiae-trifida）,a phytopathogenic fungus is a potential new agent for biological controlof this invasive plant,but its infection process is not well understood.[Method]The infection mechanisms of the rust（Puccinia xanthii sp.ambrosiae-trifidae） and its effect on the leaf structure of giant ragweed（Ambrosia trifida） were studied by means of light microscopy,scanning electron microscopy（SEM） and transmission electron microscopy（TEM）.[Result]After the rust formed haustoria,the mycelium grew into the intercellular space of the mesophyll cells.The mycelium could infect one mesophyll cell,the cell wall of which was thickened at the contact position.The branches of peripheral ragweed leaf veins were increased by infection,which led the ragweed leaves to moisture decompensation.Further,membrane damage and,organelle structure instability resulted in the cellular endomembrane system falling into disorder and the organelles becoming destabilized.[Conclusion and significance]The leaf cell structure was destroyed in the process of ragweed rust infecting,which will provide reference for control of the ragweed.