Alfalfa mosaic virus (AMV) was isolated from naturally infected periwinkle plants obtained from Giza Governorate. Characteristic symptoms, including yellow blotches, vein banding, and chlorosis, were observed. Through the isolation of single local lesions, the virus was purified biologically using Chenopodium amaranticolor Coste & Reyn. Identification of the virus was conducted by employing various methods, including symptomatology, transmissibility, and serological assays such as DAS ELISA, electron microscopy, and molecular detection. lactoferrin (LF) at different concentrations (1000, 750, 500, 250, and 100 mg/L) was used as a resistance inducer to mitigate alfalfa mosaic virus infection. The highest concentration of lactoferrin (LF), applied five days prior to inoculation, resulted in a 90% reduction in viral infection. All lactoferrin concentrations led to significant increases in phenol levels and enzyme activity. Treatment with different concentrations of LF resulted in the induction of new proteins.The maximum levels of vinblastine and vincristine were detected at the highest lactoferrin concentration, reaching 0.393 and 0.399 respectively, five days post inoculation. Lactoferrin treatments also increased the concentrations of photosynthetic pigments, including chlorophyll a, chlorophyll b, and carotenoids.