Submitted to: National American Phytopathology Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 8/14/2000
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Rice blast is a classical gene-for-gene system. Resistance occurs when the rice Pi-ta protein responds to expression of a fungal M. grisea avirulence gene AVR-Pita. We have isolated this matched pair of resistance and avirulence genes by map-based cloning. AVR-Pita is predicted to encode a processed metalloprotease. Pi-ta encodes a putative cytoplasmic protein with a nucleotide binding site and a leucine rich domain. A single nucleotide substitution of A918 with S in a natural allele of Pi-ta has resulted in loss of resistance. We demonstrated that Pi-ta bound AVR-Pita in the yeast two-hybrid system and in vitro binding. We observed that transient expression of AVR-Pita inside rice cells elicited a Pi-ta dependent hypersensitive cell death. Taken together, our data suggest that Pi-ta is an intracellular receptor that binds specifically to a fungal molecule and then activates its defense system, and that A918 is critical for recognition specificity.