Hahn M, Mendgen K
Fakultät für Biologie, Universität Konstanz, Germany.
Mol Plant Microbe Interact. 1997 May;10(4):427-37. doi: 10.1094/MPMI.1997.10.4.427.
Rust fungi are plant parasites that depend on living host tissue for growth. For invasion of leaves, dikaryotic urediospores differentiate germ tubes and infection structures that penetrate through stomata. Biotrophic growth occurs by intercellular mycelia that form haustoria within host cells. A cDNA library was constructed from haustoria isolated from broad bean leaves infected by Uromyces fabae. Differential screening revealed that a high proportion (19%) of the haustorial cDNAs are specifically expressed in planta but are not expressed, or are much weaker, in germlings or infection structures produced in vitro. A total of 31 different in planta-induced genes (PIGs) were identified. Some of the PIGs are highly expressed in haustoria. The PIGs are single or low copy number genes in the rust genome. A variety of developmentally regulated expression patterns of PIG mRNAs were observed. Sequence analysis of PIG cDNAs revealed similarities to genes encoding proteins involved in amino acid transport, thiamine biosynthesis, short-chain dehydrogenases, metallothioneins, cytochrome P-450 monooxygenases, and peptidyl-prolyl isomerases.
锈菌是依赖活的宿主组织生长的植物寄生虫。对于叶片的侵染，双核夏孢子分化出芽管和通过气孔穿透的侵染结构。活体营养生长通过在宿主细胞内形成吸器的细胞间菌丝体进行。从被蚕豆单胞锈菌感染的蚕豆叶片中分离出吸器，构建了一个cDNA文库。差异筛选显示，高比例（19%）的吸器cDNA在植物体内特异性表达，但在体外产生的芽管或侵染结构中不表达或表达较弱。总共鉴定出31个不同的植物体内诱导基因（PIGs）。一些PIGs在吸器中高度表达。PIGs在锈菌基因组中是单拷贝或低拷贝数基因。观察到PIG mRNA的多种发育调控表达模式。PIG cDNA的序列分析显示与编码参与氨基酸转运、硫胺素生物合成、短链脱氢酶、金属硫蛋白、细胞色素P-450单加氧酶和肽基脯氨酰异构酶的蛋白质的基因相似。
