KLK15 and cytomegalovirus infection: The upregulation of key genes involved in ethylene biosynthesis, including ACS (CA.PGAv.1.6.scaffold630.30) and ACO(CA.PGAv.1.6.scaffold784.1 and CA.PGAv.1.6.scaffold793.14), resulted in elevated ethylene production in CMV-infected plants, indicating that CMV infection increases ethylene emission in pepper (Figure 6).