Comparison of glyceraldehyde-3-phosphate dehydrogenase genes in Phaeosphaeria nodorum and P. avenaria species

穀類葉枯病菌Phaeosphaeria nodorum及P. avenaria之3-磷酸甘油醛脫氫酵素基因的比較

翁溥(P. P. Ueng) ； E. Reszka ； 鍾光仁(K. R. Chung) ； E. Arseniuk ； J. M. Krupinsky

《植物病理學會刊》 12卷4期 (2003/12) Pp. 255-268

https://doi.org/10.6649/PPB.200312_12(4).0006

摘要

穀類葉枯病(Stagonospora leaf blotch of cereals)是由Phaeosphaeria屬多種真菌引起的複合病害。本研究利用P. nodorum, P. avenaria f. sp. triticea(P.a.t.)及P. avenaria f. sp. avenaria(P.a.a.)三種常見的穀類葉枯病菌的3-磷酸甘油醛脫氫酵素(glyceraldehyde-3-phosphate dehydrogenase, GPD)基因(gpd)探討它們的遺傳歧異度。利用PCR增幅上述三種穀類葉枯病菌的gpd基因，發現皆含有四個內含子(intron)；在小麥P. nodorum分離株之gpd基因長度為1,253至1,255個鹽基對(bp)不等。依據這些基因的第4個內含子(intron 4)之序列差異，可將P. nodorum小麥分離株分為二個亞群(subgroups)；調查它們田間族群的分布，顯示這二個亞群間並無差異。除了Pat2分離株以外，p.a.t.群之Pat1與Pat3分離株、P.a.a.群菌株及大麥P. nodorum分離株的gpd基因長度皆為1,251bp，且彼此演化遺傳分類關係頗為相近。此外，gpd基因的核酸變化大多發生在內含子區域及胺基酸密碼子的第3個鹽基處，因此，除了Pat2分離株以外，上述三個榖類葉枯病菌的gpd基因，其推演胺基酸序列均完全一致，至於Pat2分離株的GPD蛋白質則含有2個胺基酸的差異。研究顯示前述三種穀類葉枯病菌的GPD蛋白序列和玉米病原菌Cochliobolus heterostrophus的GPD蛋白序列相當接近。根據演化遺傳分類關係之分析結果，本文中也將進一步討論這些穀類葉枯病菌與其他子囊菌間的演化關係。

關鍵字

3-磷酸甘油醛脫氫酵素基因 ； Phaeosphaeria屬 ； 穀類葉枯病 ； 小麥

並列摘要

Stagonospora leaf blotch of cereals is a complex disease caused by several Phaeosphaeria fungal species. Genetic diversity among glyceraldehydes-3-phosphate dehydrogenase (gpd) genes of Phaeosphaeria nodorum, P. avenaria f. sp. triticea (P.a.t.) and P. avenaria f. sp. avenaria (P.a.a.), three causal agents of stagonospora leaf blotch diseases in cereals, was evaluated in this study. The PCR-amplified gpd gene from these cereal Phaeosphaeria species contained 4 introns. The gpd gene in wheat-biotype P. nodorum isolates ranged in size from 1,253-1,255bp. Sequence variations in intron 4 were used to divide the wheat-biotype P. nodorum isolates into two subgroups. These two subgroups were equally represented in a survey of field wheat-biotype P. nodorum isolates. Except Pat2, the gpd genes in Patl and Pat3 of the P.a.t. group, the P.a.a. group and the barley-biotype P. nodorum were 1,251 bp in length and phylogenetically closely related. As the nucleotide changes in gpd genes occurred mostly in intron regions and the third codons of amino acid coding triplets, the deduced protein sequences in three cereal Phaeosphaeria species were identical, except for Pat2. The gpd-encoded protein in Pat2 isolates contained two amino acid substitutions. The deduced GPD proteins of three cereal Phaeosphaeria species are closely related to the GPD protein that has been described in a maize pathogen, Cochliobolus heterostrophus. Based on phylogenetic analysis, the possible evolution of these cereal Phaeosphaeria species in relation to other ascomycetes is discussed.

並列關鍵字

glyceraldehydes-3-phosphate dehydrogenase gene ； Phaeosphaeria spp. ； Stagonospora leaf blotch ； wheat