Immune Mechanism of Ethylicin-Induced Resistance to Xanthomonas oryzae pv. oryzae in Rice

Ethylicin (ET) was reported to be promising in the control
of rice
bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo). The detailed mechanism for this
process remains unknown. Disclosed here is an in-depth study on the
action mode of ET to Xoo. Through plant physiological
and biochemical analysis, it was found that ET could inhibit the proliferation
of Xoo by increasing the content of defense enzymes
and chlorophyll in rice (Oryza sativa ssp. Japonica cv. Nipponbare). Label-free quantitative proteomic
analysis showed that ET affected the rice abscisic acid (ABA) signal
pathway and made the critical differential calcium-dependent protein
kinase 24 (OsCPK24) more active. In addition, the biological function
of OsCPK24 as a mediator for rice resistance to Xoo was determined through the anti-Xoo phenotypic
test of OsCPK24 transgenic rice and the affinity
analysis of the OsCPK24 recombinant protein in vitro and ET. This
study revealed the molecular mechanism of ET-induced resistance to Xoo in rice via OsCPK24, which provided
a basis for the development of new bactericides based on the OsCPK24
protein.