Identification of Two Secreted in xylem 6 (SIX6) Genes in Fusarium oxysporum f. sp. fragariae of Korea Isolates

Strawberry Fusarium wilt, caused by Fusarium oxysporum f. sp. fragariae (FOF), poses a significant threat to strawberry production. FOF secretes effector proteins called “secreted in xylem” (SIX) into the plant’s xylem, disrupting the defense responses in the plant. In this study the proteins SIX6a and SIX6b in FOF races 1 and 2, showing race-specific expression patterns, were identified. These genes encode effector proteins with a conserved signal peptide that is typical of fungal effectors. Differential expression in susceptible strawberries suggests that FOF races regulate these effectors differently, thereby contributing to variations in pathogenicity. Understanding these effectors is crucial for the development of racespecific resistance strategies to manage Fusarium wilt in strawberries.