Hubei Key Laboratory of Plant Pathology, Huazhong Agricultural University, Wuhan 430070, China.
School of Environmental Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
Int J Mol Sci. 2021 May 31;22(11):5963. doi: 10.3390/ijms22115963.
is an important hemibiotrophic plant pathogen that causes crucifer anthracnose worldwide. To date, some hexose transporters have been identified in fungi. However, the functions of hexose transporters in virulence are not clear in hemibiotrophic phytopathogens. In this study, we identified and characterized a new hexose transporter gene named from a T-DNA insertion pathogenicity-deficient mutant G256 in . Expression profiling analysis revealed that six genes, to , exhibited specific expression patterns in different infection phases of The to were separately deleted using the principle of homologous recombination. to deletion mutants grew normally on PDA plates, but only the virulence of and deletion mutants was reduced. was required for fungal infection in both biotrophic and necrotrophic stages, while was important for formation of necrotrophic hyphae during infection. In addition, ChHxts were functional in uptake of different hexoses, but only -expressing cells could grow on all five hexoses, indicating that the ChHxt6 was a central hexose transporter and crucial for hexose uptake. Site-directed mutation of T169S and P221L positions revealed that these two positions were necessary for hexose transport, whereas only the mutation Thr169 caused reduced virulence and defect in formation of necrotrophic hyphae. Taken together, might regulate fungal virulence by modulating the utilization of hexose.
是一种重要的半活体营养型植物病原菌，可引起十字花科植物炭疽病在全球范围内流行。迄今为止，已在真菌中鉴定出一些己糖转运蛋白。然而，在半活体营养型植物病原菌中，己糖转运蛋白在毒力方面的功能尚不清楚。在这项研究中，我们从 T-DNA 插入致病性缺陷突变体 G256 中鉴定并表征了一个新的己糖转运蛋白基因，命名为 。表达谱分析显示，6 个 基因， 到 ，在 的不同感染阶段表现出特定的表达模式。使用同源重组原理分别缺失了 至 。 至 缺失突变体在 PDA 平板上正常生长，但只有 和 缺失突变体的毒力降低。 对于真菌在生物营养和坏死营养阶段的感染都是必需的，而 对于感染过程中坏死菌丝的形成是重要的。此外，ChHxts 可功能性地摄取不同的己糖，但只有表达细胞才能在所有五种己糖上生长，表明 ChHxt6 是一种中央己糖转运蛋白，对己糖摄取至关重要。T169S 和 P221L 位置的定点突变表明这两个位置对己糖转运是必要的，而只有 Thr169 突变会导致毒力降低和坏死菌丝形成缺陷。综上所述， 通过调节己糖的利用可能调节真菌的毒力。
