CAD and infection: The previous reports have indicated that lignin is deposited at the infection site to inhibit the penetration and growth of pathogens (Mutuku et al., 2019; Lee et al., 2020; Xiao et al., 2021), and relevant genes, such as PALs, CAD, and COMTs, have been confirmed, through functional genomics experiments, to be associated with disease-resistance (Tonnessen et al., 2015; Li et al., 2019; Hoch et al., 2021).