Host: The Japanese Society of Plant Physiologists
Pages 0342
Pb1 (Panicle Blast1) is a so-called field resistance gene for a fungal pathogen Magnaporthe grisea. The resistance by Pb1 is durable, of broad spectrum for fungal races, and effective especially during reproductive stages. Recently, Pb1 was isolated and encoded a Coiled Coil-Nucleotide Binding-Leucine Rich Repeat (CC-NB-LRR) protein. MLA, a CC-NB-LRR-type R protein of barley for Bluminia graminis, has been reported to translocate to the nucleus and interacts with a WRKY transcription factor (TF) after pathogen recognition. We tested the interaction of Pb1 with WRKY TFs of rice by using yeast two-hybrid, revealing that Pb1 specifically interacts with WRKY45 that plays a crucial role in plant-activator-induced resistance and salicylic-acid-mediated defense signaling in rice. While MLA-interacting WRKY TF is a transcriptional repressor, WRKY45 is a transcriptional activator; therefore the molecular mechanisms involved in the MLA- and Pb1-mediated signaling pathways are presumably different.
