The Arabidopsis RRS1-R disease resistance gene--uncovering the plant's nucleus as the new battlefield of plant defense?

The isolation of over 30 plant disease-resistance genes revealed that most genes encode putatively cytoplasmic proteins with a nucleotide-binding site (NBS) and a leucine-rich repeat (LRR). However, the recent isolation of the Arabidopsis RRS1-R gene has uncovered a novel NBS-LRR subtype that harbors a C-terminal extension with a putative nuclear localization signal and a DNA-binding domain that is characteristic of the WRKY transcription factor family. This suggests that RRS1-R, unlike any other known R protein, is targeted to the nucleus to fulfill its function.