Regulation of reactive oxygen species production by a 14-3-3 protein in elicited tobacco cells*

The regulation of the system responsible for the production of reactive oxygen species (ROS) during plant-micro- organism interaction is still largely unknown. The protein NtrbohD has been recently demonstrated as the plasma membrane oxidase responsible for ROS production in elic- ited tobacco cells. Here, its C-terminus part was used as a bait in a two-hybrid screen in order to identify putative regulators of this system. This led to the isolation of a cDNA coding for a member of the 14-3-3 protein family. The corresponding transcript was induced after infiltration of tobacco leaves with the fungal elicitor cryptogein. Tobacco cells transformed with an antisense construct of this 14-3-3 no longer accumulated ROS, which constitutes a functional validation of the two-hybrid screen. This work provides new insights to the understanding of the regulation of ROS production in a signalling context and gives a new light to the possible role of 14-3-3 proteins in plant-micro- organisms interactions.