Molecular Plant Pathology, University of Amsterdam, Amsterdam, Netherlands.
Mol Plant Pathol. 2021 Jan;22(1):108-116. doi: 10.1111/mpp.13011. Epub 2020 Nov 4.
Fusarium oxysoporum f. sp. radicis-cucumerinum (Forc) is able to cause disease in cucumber, melon, and watermelon, while F. oxysporum f. sp. melonis (Fom) can only infect melon plants. Earlier research showed that mobile chromosomes in Forc and Fom determine the difference in host range between Forc and Fom. By closely comparing these pathogenicity chromosomes combined with RNA-sequencing data, we selected 11 candidate genes that we tested for involvement in the difference in host range between Forc and Fom. One of these candidates is a putative effector gene on the Fom pathogenicity chromosome that has nonidentical homologs on the Forc pathogenicity chromosome. Four independent Forc transformants with this gene from Fom showed strongly reduced or no pathogenicity towards cucumber, while retaining pathogenicity towards melon and watermelon. This suggests that the protein encoded by this gene is recognized by an immune receptor in cucumber plants. This is the first time that a single gene has been demonstrated to determine a difference in host specificity between formae speciales of F. oxysporum.
尖镰孢黄瓜专化型（Fusarium oxysoporum f. sp. radicis-cucumerinum (Forc)）能够引起黄瓜、甜瓜和西瓜的病害，而尖镰孢甜瓜专化型（F. oxysporum f. sp. melonis (Fom)）只能感染甜瓜植物。早期的研究表明，Forc 和 Fom 中的移动染色体决定了 Forc 和 Fom 之间宿主范围的差异。通过密切比较这些致病性染色体并结合 RNA-seq 数据，我们选择了 11 个候选基因，测试它们是否参与了 Forc 和 Fom 之间宿主范围的差异。其中一个候选基因为 Fom 致病性染色体上的一个假定效应基因，在 Forc 致病性染色体上有非同源的同源物。四个具有该基因的独立 Forc 转化体对黄瓜的致病性显著降低或丧失，而对甜瓜和西瓜仍具有致病性。这表明该基因编码的蛋白被黄瓜植物中的免疫受体识别。这是首次证明单个基因决定了尖镰孢不同专化型之间宿主特异性的差异。
