However, in the comparison of the later S4 stage of infection compared with the previous three stages (S1, S2, and S3), the differentially expressed genes enriched in the plant–pathogen interaction pathway include cyclic nucleus gated channel (CNGC), mi-togen-activated protein kinase kinase kinase kinase 1 (MEKK1), mitogen-activated pro-tein kinase kinase kinase 4/5 (MKK4/5), mitogen-activated protein kinase (MAPK), WRKY transcription Factor 1/25/29 (WRKY1/25/19), resistance protein RP2 (RP2), and the suppressor of G2 allele of SKP1 (SGT1). The gene discussed is MAPK4; the disease is infection.