Dear Editor,

Sugarcane mosaic virus (SCMV) causes severe viral diseases in maize worldwide (Fuchs and Gruntzig, 1995), resulting in significant losses in grain and forage yield in susceptible cultivars of maize and related crops. The most promising solution is to cultivate resistant varieties, which contribute to sustainable crop production. Two epistatically interacting major SCMV resistance loci (Scmv1 and Scmv2) are required to confer complete resistance against SCMV in the resistant nearisogenic line F7RR/RR (the letters left of the slash refer to the genotype at Scmv2 on chromosome 3 and those on the right refer to the genotype at Scmv1 on chromosome 6, with R indicating a resistance allele and S a susceptibility allele) (Xing et al., 2006). Scmv2 adds a second layer of resistance to the immediate response mediated by Scmv1. Scmv1 has recently been identified to encode ZmTrxh, which acts as a molecular chaperone to suppress viral RNA accumulation in cytoplasm without eliciting a salicylic acid- or jasmonic acidmediated defense response (Liu et al., 2017).