Abstract
Superoxide and nitric oxide (NO) are free radicals produced by plant cells reponding to the attack of pathogens and induce various disease resistances. However, the involvement of ONOO-, a compound resulting from the reaction of Superoxide with no, in disease resistance is unknown. We previously showed generation of ONOO- in Nicotiana benthamiana treated with inf1 elicitor. ONOO- generation of rbohb , noa1 ,nr and rbohb/noa1 silenced plants was reduced, suggesting their involvement in the production of ONOO-. N. benthamiana inoculated with incompatible pathogens Colletotrichum truncatum and Pseudomonas syringae pv. glycinea induced generation of ONOO-, whereas weak/no induction was observed in the plant inoculated with compatible pathogens C. orbiculare and P. syringae pv. tabaci. rbohb/noa1 silenced plant showed enhanced susceptibility to C. orbiculare, and the treatment with ONOO- donor, cancelled the susceptibility of the silenced plant. these results suggest that ONOO- would be involved in plant resistance against pathogens.