Deciphering the SUMO code in plants

Post-translational modification (PTM) events generate proteoforms that orchestrate cell signalling in almost every biological process. The SUMOcode project aims to understand a critically important but understudied PTM in plants, SUMO (Small Ubiquitin-like Modifier). The rules governing specificity and function remain rudimentary for most PTMs, but the plant SUMO system provides a unique possibility to unravel the rules governing SUMOylation, as its core machinery comprises only 33 genes in Arabidopsis, compared with many hundreds for other PTMs. Our central hypothesis is that SUMO specificity is conferred through how cells are primed to respond to different stress signals, the tissue and cellular spatial distribution of SUMO machinery and substrates and control of SUMOylation modification via activation, repression and competition for PTM sites. Given the small numbers of genes involved in SUMOylation, we are in an excellent position to test our hypothesis employing state of the art multi-omics technologies to create the first SUMO Cell Atlas of any organism. Our ultimate goal is to 'enable' researchers and breeders to decipher the SUMO code in plants, enabling them to edit and rewrite the code, to develop crops that are future proofed against ongoing climate instability and change. Six-day old Arabidopsis seedlings were treated with 150mM of salt, 300mM of manitol, and 250nM of flagellin22. The samples were collected at 0 and 3 hours after the treatments.