Molecular Characterization of the Ribosomal Protein L25 from the Stem Rust Fungus

桿銹菌核糖體蛋白L25之分子特性

林國知(Kuo-Chih Lin) ； William R. Bushnell ； Les J. Szabo

《植物病理學會刊》 13卷4期 (2004/12) Pp. 251-260

https://doi.org/10.6649/PPB.200412_13(4).0002

摘要

從燕麥桿銹菌(Puccinia graminis f. sp. avenae)分離出25S rRNA-結合蛋白(L25)之cDNA。此cDNA長度爲660個鹽基對(bp)，可合成一條158個胺基酸之胜肽。L25之胺基酸序列與其它生物之核糖體蛋白L23/L25有極高之相似度。當燕麥桿銹菌感染宿主時，最快可於48小時偵測到L25基因之RNA；而L25基因之RNA累積的時間與桿銹菌致病株生長的時間吻合。由L23/L25蛋白之演化遺傳分類分析顯示燕麥桿銹菌L25蛋白與其它真菌之L25蛋白關係親近，且可區分Urediniomycetes，Hymenomycetes及Ustilaginomycetes（皆屬Basidiomycota），此分類結果與現有之分類相同。此外，以L23/L25蛋白分析其對Ascomycota之演化遺傳其分類結果亦與現有之分類結果吻合。此報告爲第一次以分析非核糖體RNA基因證實Basidiomycota之分類，且顯示L23/L25胺基酸序列可爲作爲研究真菌演化遺傳分類之工具。

關鍵字

Puccinia graminis ； 桿銹菌 ； 核糖體蛋白L25 ； rRNA-結合蛋白 ； 演化遺傳 ； 擔子菌綱

並列摘要

A cDNA clone (pCRL130) encoding a 25S rRNA-binding protein (L25) was isolated from the oat stem rust fungus, Puccinia graminis f. sp. avenae. The cDNA clone contains a 660 bp insert which encodes a putative polypeptide of 158 amino acids and is highly similar to those of eukaryotic ribosomal L25 proteins. Transcripts of the P. graminis L25 gene were detected as early as 48 h after host plants were inoculated with the fungus. Temporal patterns of transcript accumulation were closely correlated with fungal growth in host plants, giving more abundant transcript accumulation with compatible than with incompatible or inappropriate isolates of the fungus. Phylogenetic analysis of L23/L25 sequences divided the basidiomycetes into three well-supported lineages (Urediniomycetes, Hymenomycetes and Ustilaginomycetes) which is consistent with the current taxonomic division, based on ribosomal rDNA sequences. Similar results were obtained for taxonomic divisions among selected ascomycetes samples. This represents the first non ribosomal RNA gene analysis to confirm the division of basidiomycetes into three lineages and indicates that the L23/L25 amino acid sequence is a useful tool for studying fungal phylogenetics.

並列關鍵字

Puccinia graminis ； Stem rust fungus ； Ribosomal protein L25 ； rRNA-binding protein ； Phylogenetic ； Basidiomycota ； Basidiomycetes