Abstract
Rapid production of nitric oxide (NO) and reactive oxygen species (ROS), called NO burst and oxidative burst, respectively, is characterized during resistance to biotic and abiotic stresses. Our previous study showed that MAPK cascades regulate NO and oxidative bursts induced by INF1, which is produced by the oomycete pathogen Phytophthora infestans (Asai et al. 2008 Plant Cell). We have screened candidates related to cell death, termed CELL DEATH ASSOCIATED (CDA) genes, in randomly genes-silenced plants by VIGS. Silencing CDA1 compromised HR-like cell death induced by INF1 and MEK2DD, a constitutively active mutant of MEK2, in N. benthamiana. CDA1 encodes the gene for riboflavin synthesis. Riboflavin converts to FAD and FMN known as coenzyme of NADPH oxidase, NO synthase and nitrate reductase, indicating that CDA1 might be responsible for NO and oxidative bursts. Here, we will show effects of CDA1 silencing on production of NO and ROS and on disease resistance.
