Foster Simon J, Fitt Bruce D L
Plant-Pathogen Interactions Division, Rothamsted Research, AL5 2JQ, Harpenden, Hertfordshire, UK.
Curr Genet. 2003 Dec;44(5):277-86. doi: 10.1007/s00294-003-0445-9. Epub 2003 Sep 27.
The mating-type ( MAT) genes from Rhynchosporium secalis were isolated using PCR-based methods. Characterisation of the MAT idiomorphs suggests that R. secalis is closely related to the discomycetes Pyrenopeziza brassicae and Tapesia yallundae in terms of sequence and MAT locus gene composition. The MAT1-2 idiomorph contains a single gene encoding a protein with a high-mobility group (HMG) DNA-binding domain. The MAT1-1 idiomorph contains two genes, one encoding a protein with a HMG domain and the other encoding an alpha box domain. A second, previously undescribed, intron was identified within the P. brassicae MAT1-2-1 gene. Two introns were also present in the corresponding gene in R. secalis and this showed the similarity between these genes at the discomycete MAT1-2 locus. Using PCR, we identified isolates of both mating types from barley crops in different parts of the UK and showed that the composition of the MAT idiomorphs is conserved in these isolates. These findings support the hypothesis that R. secalis is a heterothallic discomycete which has an as yet unidentified teleomorph.
利用基于聚合酶链反应（PCR）的方法从大麦网斑病菌（Rhynchosporium secalis）中分离出交配型（MAT）基因。对MAT特异型的特征分析表明，就序列和MAT基因座基因组成而言，大麦网斑病菌与盘菌纲的芸苔生小球腔菌（Pyrenopeziza brassicae）和燕麦散斑壳菌（Tapesia yallundae）密切相关。MAT1-2特异型包含一个单一基因，该基因编码一种具有高迁移率族（HMG）DNA结合结构域的蛋白质。MAT1-1特异型包含两个基因，一个编码具有HMG结构域的蛋白质，另一个编码α盒结构域。在芸苔生小球腔菌MAT1-2-1基因中鉴定出第二个以前未描述的内含子。大麦网斑病菌相应基因中也存在两个内含子，这表明在盘菌纲MAT1-2基因座处这些基因之间具有相似性。通过PCR，我们在英国不同地区的大麦作物中鉴定出了两种交配型的分离株，并表明这些分离株中MAT特异型的组成是保守的。这些发现支持了大麦网斑病菌是一种异宗配合盘菌且具有尚未鉴定的有性型的假说。
