Megann Tran

1 INTRODUCTION Bacterial vector-borne (VB) diseases impact agriculture worldwide. Members of the genus ‘Candidatus Liberibacter’ (hereafter Liberibacter) cause diseases on a range of economically important crops like potatoes, carrots, celery and citrus, with impacts on citrus decimating the Florida citrus industry (Wang et al., 2017).

Abstract Reactive oxygen species (ROS) accumulation is required for effective plant defense. Accumulation of the Arabidopsis NADPH oxidase RBOHD is regulated by phosphorylation of a conserved C-terminal residue (T912) leading to ubiquitination by the RING E3 ligase PIRE. Arabidopsis PIRE knockouts exhibit enhanced ROS production and resistance to the foliar pathogen Pseudomonas syringae. Here, we identified 170 PIRE homologs, which emerged in tracheophytes and expanded in angiosperms.