Downregulation of Light-Harvesting Complex II Induces ROS-Mediated Defense Against Turnip Mosaic Virus Infection in .

The light-harvesting chlorophyll / complex protein 3 (LHCB3) of photosystem II plays important roles distributing the excitation energy and modulating the rate of state transition and stomatal response to abscisic acid. However, the functions of LHCB3 in plant immunity have not been well investigated. Here, we show that the expression of in () was down-regulated by turnip mosaic virus (TuMV) infection. When was silenced by tobacco rattle virus-induced gene silencing, systemic infection of TuMV was inhibited. HO was over-accumulated in -silenced plants. Chemical treatment to inhibit or eliminate reactive oxygen species (ROS) impaired the resistance of the -silenced plants to TuMV infection. Co-silencing of with genes involved in ROS production compromised the resistance of plants to TuMV but co-silencing of with genes in the ROS scavenging pathway increased resistance to the virus. Transgenic plants overexpressing were more susceptible to TuMV. These results indicate that downregulation of is involved in defense against TuMV by inducing ROS production.