León-Ramírez Claudia G, Cabrera-Ponce José Luis, Martínez-Espinoza Alfredo D, Herrera-Estrella Luis, Méndez Lucila, Reynaga-Peña Cristina G, Ruiz-Herrera José
both authors have contributed equally to this work.
Present address: Department of Plant Pathology, University of Georgia, Griffin Campus 1109 Experiment St., Griffin, GA 30223-1797, USA.
New Phytol. 2004 Nov;164(2):337-346. doi: 10.1111/j.1469-8137.2004.01171.x.
• Here, the host specificity of the corn smut fungus Ustilago maydis was analyzed, with the long-term objective of understanding the different aspects of its pathogenic behavior. • Axenic plantlets obtained in vitro, including one gymnosperm, monocotyledons and dicotyledons, were inoculated with a diploid strain of U. maydis, incubated in a growth chamber, and observed periodically. • All plants were susceptible to infection. The most common symptoms were growth of fungal mycelium on stems and leaves, increase in root number in monocots, or development of adventitious roots in dicots. Other symptoms - chlorosis, increased anthocyanins, necrosis and stunting - varied among the different plant species. Ustilago penetrated and grew into the plant tissues in the form of pleomorphic mycelium, but no teliospores were formed. Noticeably, the fungus induced formation of lateral buds and tumors in papaya. • The results provide evidence that U. maydis is able to infect a variety of phylogenetically unrelated plants grown under axenic conditions. These results may be useful in the analysis of different phenomena associated with the complex pathogenic behavior of U. maydis.
• 在此，对玉米黑粉菌Ustilago maydis的宿主特异性进行了分析，其长期目标是了解其致病行为的不同方面。
• 用U. maydis的二倍体菌株接种在体外获得的无菌幼苗，包括一种裸子植物、单子叶植物和双子叶植物，在生长室中培养，并定期观察。
• 所有植物均易受感染。最常见的症状是真菌菌丝体在茎和叶上生长，单子叶植物的根数增加，或双子叶植物不定根的发育。其他症状——黄化、花青素增加、坏死和发育迟缓——在不同植物物种中各不相同。Ustilago以多形菌丝体的形式侵入并生长到植物组织中，但未形成冬孢子。值得注意的是，该真菌在木瓜中诱导侧芽和肿瘤的形成。
• 结果表明，U. maydis能够感染在无菌条件下生长的多种系统发育无关的植物。这些结果可能有助于分析与U. maydis复杂致病行为相关的不同现象。
