Role of salicylic acid in resistance to plant viruses

Salicylic acid plays a key role in plants defense against viruses. Induced systemic acquired resistance causes long lasting resistance to a wide range of pathogens including viruses. Salicylic acid can interfere in three main stages of virus pathogenicity cycle including replication, cell to cell movement and long distance movement. Transcriptional factors of TGA, MYB and WRKY families play a role in salicylic acid resistance to viruses. Salicylic acid induces expression of pathogenicity related proteins through a NPR1 dependent pathway in hypersensitive response and systemic acquired resistance. Independent signaling pathway of NPR1 is a different form of salicylilic acid dependent signal transduction which is required for specific resistance to plant viruses. Also, salicylic acid induces expression of RNA dependent RNA polymerase genes in Arabidopsis and Nicotiana plants which play an essential role in RNA silencing. Finally understanding of salicylic acid biology and its signaling pathways can increase resistance to stresses and product yield.