Retardation of the Calvin Cycle Contributes to the Reduced CO Assimilation Ability of Rice Stripe Virus-Infected and Suppresses Viral Infection.

Rice stripe virus (RSV) is naturally transmitted by the small brown planthopper and infects plants of the family . Under laboratory conditions, RSV can infect by mechanical inoculation, providing a useful system to study RSV-plant interactions. Measurements of CO assimilation ability and PSII photochemical efficiency showed that these were both reduced in plants infected by RSV. These plants also had decreased expression of the (), the key gene in the Calvin cycle. When the were silenced using the TRV-Virus Induced Gene Silencing system, the plants had decreased CO assimilation ability, indicating that the downregulated expression of contributes to the reduced CO assimilation ability of RSV-infected plants. Additionally, -silenced plants were more resistant to RSV. Similarly, resistance was enhanced by silencing of either small subunit () or (), two other key genes in the Calvin cycle. Conversely, transgenic plants overexpressing were more susceptible to RSV infection. The results suggest that a normally functional Calvin cycle may be necessary for RSV infection of .