Virus-induced gene silencing (VIGS) of the NBS-LRR gene SLNLC1 compromises Sm-mediated disease resistance to Stemphylium lycopersici in tomato

In a previous study, when resistant tomato plants (cv. Motelle) carrying the Sm gene were challenged with S. lycopersici, the SLNLC1 gene was significantly upregulated. In this study, to verify the function of the SLNLC1 gene response to disease resistance against S. lycopersici, virus-induced gene silencing (VIGS) was used to downregulate the expression level of the SLNLC1 gene in resistant tomato plants inoculated with S. lycopersici. After inoculation with S. lycopersici, a susceptible phenotype was observed in the silenced SLNLC1-resistant plants. Through microscopy, impaired hypersensitive response (HR) and decreased ROS accumulation were also observed in the silenced SLNLC1 plants. In addition, the production of lignin and callose were decreased in the silenced SLNLC1 plants. Taken together, these results indicated that silencing the SLNLC1 gene attenuated the resistance of tomato plants resistant to S. lycopersici.