Host apoplastic nutrients might influence the proliferating biotroph, therefore, we analyzed the effect of host apoplastic nutrients on the virulence strategy of E. orontii (a biotroph model). E. orontii was initially treated with the analogs of commonly found apoplastic nutrients in a culture media. The analogs included Cyanoalanine (CAL), Trehalose, H2O2, acidic water (0.3% H3PO4), NaNO3, and MgSO4. After pre-treatment with the analogs of apoplastic nutrients, E. orontii was then inoculated to the host plants. After 5 and 8 days of post-infection (dpi), the virulence of E. orontii was determined through the expression of 20 virulence factor and 7 host defence genes. The expression of AVRk1, Ekal1, Ekal2, Ekal3, Ekal4, Ekal5, Ekal6, Ekal7, Ekal8, Epul5, Epul6, Epul7, Epul8, Epul9, Epul10, Epul11, Epul12, Epul5, Epul17 was determined as a virulence factor and expression of PR1, ERF1, PDF1.2a, PMRs, DMRs, IOS1, MYB3R4 was determined as host defence genes. The results revealed that the tested analogs vigorously affected the phenotypic and genotypic properties of E. orontii and thus its biotrophic virulence strategy. Certainly, the exogenous application of fungal growth-promoting apoplastic nutrients (CAL or TRE) severely reduced the virulence of E. orontii. Contrarily, the stress-inducing apoplastic analogs (H2O2 or acidic water) surprisingly increased the virulence of E. orontii. Moreover, the application of NaNO3 or MgSO4 decoyed the fungal growth and thus decreasing the E. orontii virulence.