Exploiting pipazethate HCL as a plant defense activator targeting salicylic acid pathway in rice against blast disease caused by Pyricularia oryzae

Globally, blast disease in rice is one of the most important challenges limiting affected on rice crop productivity. Systemic acquired resistance (SAR) has been broadly investigated in a variety of plant species for enhancing inner resistance to various phytopathogens. The present study aimed to investigate the potential impact of pipazethate HCL as a substance of SAR against Pyricularia oryzae in rice. The results indicated that pipazethate HCl has no effect on the linear growth of P. oryzae at various concentrations in vitro. However, it significantly enhanced the level of resistance to rice blast fungus at different concentrations under greenhouse conditions. Furthermore, pipazethate HCL, salicylic acid, and tricyclazole 75 % WP are significantly decreasing the number of spores produced on infected rice lesions. Additionally, pipazethate HCL activates some salicylic acid (SA) signaling pathway indicators such as OsWRKY45 and OsNPR1, but jasmonic acid (JA) pathways such as AOS2, JAMYB, and PBZ1 (OsPR10) are not clear. The results suggested that pipazethate HCL is a salicylic acid analog against blast disease in rice inducing SAR that might be interrelated with the defense pathways of SA.