ABCD2 and infection: AGD2-LIKE DEFENSE PROTEIN1 (ALD1), a diaminopimelate aminotransferase, is responsible for early SA accumulation during ETI as well as for the biosynthesis of pipecolic acid (Pip)/N-hydroxy-Pip (NHP) during infections that lead to SAR (Song et al., 2004a; 2004b; Návarová et al., 2012; Sobolev et al., 2013; Hartmann et al., 2017; 2018; Chen et al., 2018; Jiang et al., 2021).