K48- and K63-linked ubiquitination in plant development and stress responses

Ubiquitination is a crucial post-translational modification regulating numerous biological processes in plant development and stress responses. This process involves the covalent attachment of ubiquitin molecules to different target proteins, primarily linked through lysine (K)48 or K63 residues of ubiquitin, which either marks them for degradation by the 26S proteasome or modifies their activity, localization, and stability. By modulating key regulatory proteins and signaling pathways, ubiquitination enables plants to adapt to challenging environments. K48-linked ubiquitination is the most prevalent form in plants, although some recent studies have also demonstrated the importance of K63-linked ubiquitination. This review focuses on the roles of K48- and K63-linked ubiquitination in plant development, including seed dormancy and germination, seed size, hypocotyl elongation, and flowering time, as well as in abiotic and biotic stresses. Furthermore, it highlights their potential functions in improving crop resilience through biotechnological strategies. Finally, we also discuss the future challenges in investigating plant regulatory networks mediated by protein ubiquitination.