Abstract text: The Arabidopsis thaliana pectate lyase PLL12 is thought to fragment demethylated pectin into Oligogalacturonans. The protein’s enzymatic activity is directly linked to sieve element development in the phloem, whereas ectopic expression in non-native tissues, particularly the mesophyll, mimics pathogen attack and triggers strong lignification. With strong phenotypes for its deletion and overexpression, we aim to use them as tools to further investigate the molecular mechanism underlying the developmental importance of the pectate lyase as well as how the developmental cues differ from the stress response the plant endures during overexpression. Due to the vastness of genes that have already been related to pectin responses, we combine forward and reverse genetic approaches, including a suppressor screen on the mutagenised knock-out pll12-2 and transcriptomic as well as translatomic analyses, to identify candidate genes contributing to these distinct responses.