Abstract
The main defense response to Soybean mosaic virus (SMV) infection in soybean [Glycine max (L.) Merr.] is thought to be blockage of intercellular virus transport by callose deposition on plasmodesmata. But the specific regulatory mechanism remains largely unknown. In this study, we found that hydrogen peroxide (H2O2) signal downstream of NO was associated with the regulation of callose accumulation. Abundant H2O2 was produced on the cell membrane and cell wall in the incompatible combination of soybean cultivar Jidou 7 and SMV strain N3, whereas no obvious H2O2 was observed in the compatible combination of Jidou 7 and strain SC-8. When H2O2 production was inhibited, callose accumulation induced by SMV infection decreased to a level insufficient to restrict virus transport in the incompatible combination. The H2O2-associated transcriptome dynamics of soybean during SMV infection was investigated. Transcriptome and functional analysis using virus-induced gene silencing showed that GmSEOB and GmPAP27, two genes regulated by H2O2, functioned in resistance by positively regulating the accumulation of callose in response to SMV infection. These results lay a foundation for further research on the signal transduction and molecular regulation of callose deposition during soybean resistance to SMV infection.
