Gene silencing (GS) is considered a promising tool for studying gene functions, improving various crop traits as well as providing resistance to pathogens. Silencing may be done at the transcript or at the post-transcript level. Gene silencing can be done using either RNAi or CRISPR. RNAi silences genes by generating knockdowns at the mRNA level, while CRISPR generates knockouts at the DNA level. Genetic silencing played an important role in protecting plants from pathogens, silencing the synthesis pathways of many compounds in plants such as nicotine, caffeine and gluten, as well as improving the quality of fruits and prolonging their shelf life, but silencing by traditional methods requires genetic modification of the plant and this takes a long time in addition to these, genetically modified plants has faced great rejection from most societies. Induction of gene silencing by external spraying of dsRNA molecules complementary to the pathogen’s gene on plant is one of the modern, fast, inexpensive, and environmentally friendly methods that do not require genetic modification of plant and will enhance plant resistance against many pathogens. This application is recognized as spray-induced gene silencing (SIGS).