Regulation of sugar transporter activity for antibacterial defense in Arabidopsis
K. YAMADA (1), Y. Saijo (2), Y. Takano (1) (1) Kyoto University, Japan; (2) NAIST, Japan

Microbial pathogens acquire nutrients from their hosts during infection. While nutrient uptake competition is believed to occur at the host-pathogen interface, compelling molecular evidence is lacking. Recent studies have revealed strategies used by phytopathogens to capture nutrients, but it remains unclear whether plants directly prevent nutrient loss to pathogens. Here we show that enhancement of sugar transporter activity is required for antibacterial defense in the model plant Arabidopsis thaliana. We found that extracellular (apoplastic) sugar levels are regulated by Arabidopsis plasma membrane-localized sugar transporters during pattern-triggered immunity (PTI), which follows recognition of pathogen-associated molecular patterns (PAMPs). A sugar transporter is strongly induced, and physically associates with PAMP receptor complexes. We found that a sugar transporter is phosphorylated, leading to enhancement of its transporter activity. Furthermore, our data suggested the significance of its phosphorylation in antibacterial defense. Taken together, our findings illuminate that active control of apoplastic sugar levels, via regulation of sugar transporter at the transcriptional and post-translational levels, plays a critical role in plant immunity.

Abstract Number: P17-641
Session Type: Poster