EDS5, an Essential Component of Salicylic Acid–Dependent Signaling for Disease Resistance in Arabidopsis, Is a Member of the MATE Transporter Family

TLDR

EDS5, a mutant in Arabidopsis, shows reduced salicylic acid and PR‑1 expression after pathogen challenge and is highly susceptible, and it belongs to the MATE transporter family. EDS5 was isolated by positional cloning and encodes a protein with nine to eleven transmembrane domains and an N‑terminal coil domain. EDS5 expression is low in unstressed plants but is strongly induced by pathogens, UV‑C light, and salicylic acid, remaining elevated for about two days and requiring EDS1, PAD4, and NDR1 for induction.

Abstract

The eds5 mutant of Arabidopsis (earlier named sid1) was shown previously to accumulate very little salicylic acid and PR-1 transcript after pathogen inoculation and to be hypersusceptible to pathogens. We have isolated EDS5 by positional cloning and show that it encodes a protein with a predicted series of nine to 11 membrane-spanning domains and a coil domain at the N terminus. EDS5 is homologous with members of the MATE (multidrug and toxin extrusion) transporter family. EDS5 expression is very low in unstressed plants and strongly induced by pathogens and UV-C light. The transcript starts to accumulate 2 hr after inoculation of Arabidopsis with an avirulent strain of Pseudomonas syringae or UV-C light exposure, and it stays induced for ∼2 days. EDS5 also is expressed after treatments with salicylic acid, indicating a possible positive feedback regulation. EDS5 expression after infection by certain pathogens as well as after UV-C light exposure depends on the pathogen response proteins EDS1, PAD4, and NDR1, indicating that the signal transduction pathways after UV-C light exposure and pathogen inoculation share common elements.