FMO5 and infection: This increase in ROS accumulation in the Sl3-MMP-silenced plants was mainly due to an accelerated ROS generation rather than a reduced ROS scavenging ability because the expression levels of SlRboh1 and SlWfi1, coding for NADPH oxidases that are plasma membrane-localized ROS generating enzymes [41], were significantly higher but the expression levels of SlCAT and SlSOD, coding enzymes capable of scavenging ROS [42] were similar to those in the control plants after infection of B. cinerea (Fig. 8a).