A role of auxin produced by phytopathogenic fungi during biotrophic phase

稻瘟病菌在感染和侵入宿主组织的早期阶段需要活的植物细胞。免疫组织化学分析表明，抗吲哚-3-乙酸单克隆抗体的抗原定位于水稻组织中的真菌感染菌丝。含有生长素诱导型报告基因构建体的水稻转化体在真菌入侵活组织后，在感染菌丝的顶端周围表现出生长素反应。这些结果表明，稻瘟病菌在其活体营养期产生少量的生长素，侵入的水稻组织对外源真菌生长素有反应。此外，利用原位杂交技术，还可以对寄主组织中的活体营养真菌菌丝进行种特异性观察。

The rice blast fungus Magnaporthe oryzae requires living plant cells in its early stages of infection and invasion of host tissue. Immunohistological analyses showed that antigens of the anti-indole-3-acetic acid monoclonal antibody were localized in the fungal infection hyphae present in the rice tissue. Rice transformants containing an auxin-inducible reporter construct demonstrated an auxin response around the apex of the infection hyphae after fungal invasion of living tissue. These results suggest that the rice blast fungus produces a small amount of auxin during its biotrophic phase and the invaded rice tissue responds to the exogenous fungal auxin. In addition, it was shown that the biotrophic fungal hyphae in host tissues were able to be visualized species-specifically by using in situ hybridization technique.