利用绿色荧光蛋白GFP研究稻瘟病菌与水稻的互作

稻瘟病菌Magnaporthe oryzae严重威胁水稻的产量与质量,明确稻瘟病菌与水稻互作过程及机理,对防治稻瘟病具有重要意义。本研究利用稻瘟病菌常用致病菌株GUY11和ZB25,构建了绿色荧光蛋白GFP的过量表达菌株,并通过荧光显微观察菌株侵染寄主水稻过程中侵染结构的形成与发育,包括孢子萌发、附着胞形成、侵染钉形成、侵染菌丝增殖、坏死斑形成及产孢。另外,通过比较过量表达菌株对稻瘟病高抗水稻和易感水稻的侵染过程,发现侵染过程的差异主要集中于侵染钉的穿透和侵染菌丝的定殖。本研究为分析稻瘟病菌对寄主水稻的定殖规律提供了一种有效工具。

Fluorescent microscopic analysis of the plant infection process of Magnaporthe oryzae using green fluorescent protein

Blast disease caused by the fungus Magnaporthe oryzae leads to tremendous loss in production and quality of rice worldwide. To effectively control rice blast disease, we need to understand the infection process and pathogenic mechanism of M. oryzae. Green fluorescent protein (GFP) has been widely used as a labelling tool in life science research. Here we report the construction of a vector overexpressing GFP and the successful introduction of the vector into two commonly used M. oryzae strains Guy11 and ZB25. By using the resulting fungal transformants overexpressing GFP, we observed the successional and dynamic plant infection processes by M. oryzae including conidial germination, germ tube elongation, and formation of an appressorium and penetration peg, proliferation of infection hyphae within the rice tissue, appearance of blast lesion, development of conidiophore and production of conidia at the blast lesion. We also compared the infection processes of M. oryzae between interactions with compatible rice host and incompatible host, and found that M. oryzae underwent normal appressorium on both rice hosts. After the formation of appressorium, M. oryzae was able to develop penetration peg and invasive hyphae within rice tissue in a compatible interaction, but lost these abilities in an incompatible interaction. Our study proves that the M. oryzae expressing GFP facilitates our observation of the processes of M. oryzae infection on rice plant, thus providing an effective tool for examination of pathogen-plant interaction.