Fusarium oxysporum f. sp. lycopersici is an important plant pathogen that has been used to understand the virulence mechanisms that soil inhabiting fungi exhibit during the infection process. In F. oxysporum many of the virulence factors are secreted, and the secretion process requires the formation of vesicles. Arf family members, represented by Arf (ADP- Ribosylation Factor), Arl (Arf-like), and Sar (Secretion-associated and Ras-related) proteins, are involved in the vesicle creation process. In this study we identified the Arf family members in F. oxysporum f. sp. lycopersici, which includes seven putative proteins: Arf1, Arf3, Arl1 through Arl3, Arl8B, and Sar1. Quantification of the mRNA levels of each arf encoding gene revealed that the highest expression corresponds to arf1 in all tested conditions. The phylogenetic analysis revealed that no other Arf1 paralogue, such as Arf2 from yeast, is present in F. oxysporum f. sp. lycopersici. The essential function suggested of Arf1 in F. oxysporum f. sp. lycopersici was corroborated experimentally when, after several attempts, it was impossible to obtain a knockout mutant in arf1. Moreover, arl3 mRNA levels increased significantly when plant tissue was added as a sole carbon source, suggesting that the product of these genes could play pivotal roles during plant infection, the corresponding mutant ∆arl3 was less virulent compared to the wild-type strain. These results describe the role of arl3 as a critical regulator of the virulence in F. oxysporum f. sp. lycopersici and stablish a framework for the arf family members to be studied in deeper details in this phytopathogen.

Fusarium oxysporum f. sp。lycopersici是一种重要的植物病原体，已被用于了解土壤栖息真菌在感染过程中表现出的毒力机制。在F. oxysporum中分泌了许多毒力因子，分泌过程需要形成囊泡。Arf 家族成员，以 Arf（ADP-核糖基化因子）、Arl（Arf 样）和 Sar（分泌相关和 Ras 相关）蛋白为代表，参与囊泡产生过程。在这项研究中，我们确定了F. oxysporum f中的 Arf 家族成员。sp。lycopersici，其中包括七种推定的蛋白质：Arf1、Arf3、Arl1 到 Arl3、Arl8B 和 Sar1。量化每个的 mRNA 水平arf编码基因显示最高表达对应于所有测试条件下的arf1 。系统发育分析表明， F. oxysporum f中不存在其他 Arf1 旁系同源物，例如来自酵母的 Arf2 。sp。番茄。提出的 Arf1 在F. oxysporum f 中的基本功能。sp。lycopersici在经过多次尝试后无法在arf1中获得基因敲除突变体时通过实验得到证实。此外，arl3当添加植物组织作为唯一碳源时，mRNA 水平显着增加，表明这些基因的产物在植物感染过程中可能发挥关键作用，相应的突变体Δarl3与野生型菌株相比毒性较低。这些结果描述了arl3作为F. oxysporum f 中毒力的关键调节剂的作用。sp。lycopersici并为arf家族成员建立一个框架，以便在这种植物病原体中进行更深入的研究。