Salicylic acid ( SA) is a signaling molecule to trigger defenses against diverse pathogens including the bacterial wilt on Irish potato. Salicilic acid-aspirin combination can neutralise the plant cell wall degrading enzymes produced by the pathogen. It can inhibit the induction of genes coding for pathogen related proteins elicited by the bacteria. It has been found that at a concentration of 50 micromole SA the protected effect against bacterial wilt is almost complete. SA can also cause morphological and transitional changes in bacterial cell.
salicylic acid-aspirin is useful as a pharmaceutical product . What is the purpose of testing for antimicrobial activity. Salicylic acid is used in skin ointments as antifungal agent.It may work as antifungal agent for plant pathogen.