A new member of the Arabidopsis WRKY transcription factor family, AtWRKY6,is associated with both senescence- and defence-related processes

WRKY proteins constitute a large family of plant-specific transcription fac tors whose precise functions have yet to be elucidated. Here we show that e xpression of one representative in Arabidopsis, AtWRKY6, is influenced by s everal external and internal signals often involved in triggering senescenc e processes and plant defence responses. Progressive 5' deletions of the At WRKY6 promoter allowed separation of defined regions responsible for the ex pression in distinct organs or upon pathogen challenge. Nuclear localizatio n of AtWRKY6 was demonstrated; protein truncations and gain-of-function stu dies enabled delineation of a region harbouring a novel type of functional nuclear localization signal (NLS).