E3 ubiquitin ligases are major components of the ubiquitination cascade and contribute to the stomatal responses to pathogen and drought stress in plants. The F-box SKP1-Interacting Partners (AtSKIPs) proteins are members of the SCF E3 ubiquitin ligase complexes
however, whether they have any involvement in stomatal movement remains unclear. Here, based on tissue expression profiling, we found that the AtSKIP5 protein was highly expressed in guard cells. Mutation of AtSKIP5 rendered plants more susceptible to Pseudomonas syringae pv. tomato (Pst) DC3000 and resulted in a significant impairment in stomatal closure after flg22 and Pst DC3000 treatment. Consistently, lines overexpressing AtSKIP5 were more resistant to Pst DC3000 infection and exhibited more rapid stomatal closure than did other lines. However, the AtSKIP5-overexpressing lines and Col-0 line were similarly resistant to Pst