Suga Haruhisha, Kageyama Koji, Shimizu Masafumi, Hyakumachi Misturo
Life Science Research Center, Gifu University, 501-1193, Japan
River Basin Research Center, Gifu University, 501-1193, Japan.
G3 (Bethesda). 2016 Dec 7;6(12):3883-3892. doi: 10.1534/g3.116.033951.
Members of the Fusarium graminearum species complex (Fg complex or FGSC) are the primary pathogens causing Fusarium head blight in wheat and barley worldwide. A natural pathogenicity mutant (strain 0225022) was found in a sample of the Fg complex collected in Japan. The mutant strain did not induce symptoms in wheat spikes beyond the point of inoculation, and did not form perithecia. No segregation of phenotypic deficiencies occurred in the progenies of a cross between the mutant and a fully pathogenic wild-type strain, which suggested that a single genetic locus controlled both traits. The locus was mapped to chromosome 2 by using sequence-tagged markers; and a deletion of ∼3 kb was detected in the mapped region of the mutant strain. The wild-type strain contains the FGSG_02810 gene, encoding a putative glycosylphosphatidylinositol anchor protein, in this region. The contribution of FGSG_02810 to pathogenicity and perithecium formation was confirmed by complementation in the mutant strain using gene transfer, and by gene disruption in the wild-type strain.
禾谷镰刀菌复合种（Fg复合种或FGSC）的成员是全球范围内导致小麦和大麦赤霉病的主要病原菌。在日本采集的一份Fg复合种样本中发现了一个自然致病性突变体（菌株0225022）。该突变菌株在接种点以外的小麦穗中未诱导出症状，也未形成子囊壳。突变体与完全致病的野生型菌株杂交后代中未出现表型缺陷的分离，这表明单一基因座控制这两个性状。通过使用序列标签标记将该基因座定位到2号染色体；并且在突变菌株的定位区域检测到约3 kb的缺失。野生型菌株在该区域含有FGSG_02810基因，编码一种假定的糖基磷脂酰肌醇锚定蛋白。通过在突变菌株中进行基因转移互补以及在野生型菌株中进行基因破坏，证实了FGSG_02810对致病性和子囊壳形成的作用。
