SNAREs (soluble N‐ethylmaleimide‐sensitive factor attachment protein receptors) facilitate docking and fusion of vesicles with their target membranes, playing a crucial role in vesicle trafficking and exocytosis. However, the spatial assembly and roles of plasma membrane (PM)‐associated SNAREs in phytopathogen development and pathogenicity are not clearly understood. In this study, we analysed the roles and molecular mechanisms of PM‐associated SNARE complexes in the banana Fusarium wilt fungus Fusarium oxysporum f. sp. cubense tropical race 4 (FocTR4). Our findings demonstrate that FocSso1 is important for the fungal growth, conidiation, host penetration and colonization. Mechanistically, FocSso1 regulates protein secretion by mediating vesicle docking and fusion with the PM and hyphal apex. Interestingly, a FocSso1–FocSec9–FocSnc1 complex was observed to assemble not only at the fungal PM but also on the growing hyphal apex, facilitating exocytosis. FocSso2, a paralogue of FocSso1, was also found to form a ternary SNARE complex with FocSec9 and FocSnc1, but it mainly localizes to the PM in old hyphae. The functional analysis of this protein demonstrated that it is dispensable for the fungal growth but necessary for host penetration and colonization. The other subunits, FocSec9 and FocSnc1, are involved in the fungal development and facilitate host penetration. Furthermore, FocSso1 and FocSnc1 are functionally interdependent, as loss of FocSso1 leads to mis‐sorting and degradation of FocSnc1 in the vacuole and vice versa. Overall, this study provides insight into the formation of two spatially and functionally distinct PM SNARE complexes and their involvement in vesicle exocytosis to regulate development and pathogenicity of FocTR4.

中文翻译：

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两种不同的 SNARE 复合物介导囊泡与质膜的融合，以确保尖镰孢的有效发育和发病机制。 sp。库本塞

SNARE（可溶性氮‐乙基马来酰亚胺敏感因子附着蛋白受体）促进囊泡与其靶膜的对接和融合，在囊泡运输和胞吐作用中发挥着至关重要的作用。然而，质膜（PM）相关 SNARE 在植物病原体发育和致病性中的空间组装和作用尚不清楚。在本研究中，我们分析了 PM 相关 SNARE 复合物在香蕉枯萎病真菌中的作用和分子机制尖孢镰刀菌F。 sp。库本塞热带种族 4 (FocTR4)。我们的研究结果表明 FocSso1 对于真菌生长、分生孢子形成、宿主渗透和定植非常重要。从机制上讲，FocSso1 通过介导囊泡与 PM 和菌丝顶端的对接和融合来调节蛋白质分泌。有趣的是，观察到 FocSso1-FocSec9-FocSnc1 复合物不仅在真菌 PM 上组装，而且还在生长的菌丝顶端组装，促进胞吐作用。 FocSso2是FocSso1的旁系同源物，也被发现与FocSec9和FocSnc1形成三元SNARE复合物，但它主要定位于老菌丝中的PM。该蛋白质的功能分析表明，它对于真菌生长是可有可无的，但对于宿主渗透和定殖是必需的。其他亚基 FocSec9 和 FocSnc1 参与真菌发育并促进宿主渗透。此外，FocSso1 和 FocSnc1 在功能上是相互依赖的，因为 FocSso1 的丢失会导致液泡中 FocSnc1 的错误分类和降解，反之亦然。总体而言，本研究深入了解了两个空间和功能不同的 PM SNARE 复合物的形成及其参与囊泡胞吐作用以调节 FocTR4 的发育和致病性。