RBOHA A RICE HOMOLOG OF THE MAMMALIAN GP91PHOX RESPIRATORY BURST OXIDASE GENE

It has been hypothesized that plants contain respiratory burst oxidase s which, upon activation, oxidize NADPH and generate extracellular sup eroxide, O-2(.-) These proteins are proposed to play a central role in defence against pathogens. However, plant DNA sequences that encode p roteins with similarity to components of respiratory burst oxidases ha ve not previously been reported. This paper describes the complete cDN A and genomic DNA sequence of the rice rbohA (for respiratory burst ox idase homologue) gene. The predicted RbohA product is most similar to the main catalytic subunit, gp91phox, of the respiratory burst oxidase of neutrophils. Reverse transcriptase PCR detects rbohA transcripts i n both roots and shoots of healthy rice plants.