Mendgen Kurt, Wirsel Stefan G R, Jux Andreas, Hoffmann Jochen, Boland Wilhelm
Lehrstuhl Phytopathologie, Fachbereich Biologie, Universität Konstanz, Universitätsstr.10, 78457, Konstanz, Germany.
Planta. 2006 Nov;224(6):1353-61. doi: 10.1007/s00425-006-0320-2. Epub 2006 Jun 15.
Rust fungi are obligate biotrophic pathogens that differentiate a series of specialized cells to establish infection. One of these cells, the haustorium, which serves to absorb nutrients from living host cells, normally develops only in planta. Here, we show that the rust fungus Uromyces fabae (Pers.) Schroet. stimulates volatile emission of its host, broad bean (Vicia faba L.). Volatiles were identified and shown to be perceived by the fungus in in vitro assays that excluded the host. Three of them, nonanal, decanal, and hexenyl acetate promoted the development of haustoria on artificial membranes. In contrast, the terpenoid farnesyl acetate suppressed this differentiation. In assays using whole plants, farnesyl acetate reduced rust disease not only on broad bean but also on several cereals and legumes including soybean. This natural substance was effective against all rusts tested when directly applied to the host. This demonstrated that farnesyl acetate may serve as a powerful novel tool to combat rust fungi including Phakopsora pachyrhizi that currently threatens the production of soybeans world-wide.
锈菌是专性活体营养型病原体，可分化出一系列特化细胞来建立感染。其中一种细胞，吸器，用于从活的宿主细胞中吸收养分，通常仅在植物体内发育。在此，我们表明锈菌蚕豆单胞锈菌（Uromyces fabae (Pers.) Schroet.）能刺激其宿主蚕豆（Vicia faba L.）释放挥发性物质。挥发性物质经鉴定后，在排除宿主的体外试验中显示能被该真菌感知。其中三种，壬醛、癸醛和乙酸己烯酯，促进了人工膜上吸器的发育。相反，萜类物质乙酸法呢酯抑制了这种分化。在对整株植物进行的试验中，乙酸法呢酯不仅能减轻蚕豆上的锈病，还能减轻包括大豆在内的几种谷物和豆类上的锈病。当直接施用于宿主时，这种天然物质对所有测试的锈菌都有效。这表明乙酸法呢酯可能成为对抗锈菌的一种强大新工具，包括目前威胁全球大豆生产的大豆锈菌（Phakopsora pachyrhizi）。
