Sugarcane mosaic virus （SCMV） causes substantial losses of grain yield and forage biomass in susceptible maize worldwide. A major quantitative trait locus, Scmvl, has been identified to impart strong resistance to S...Sugarcane mosaic virus （SCMV） causes substantial losses of grain yield and forage biomass in susceptible maize worldwide. A major quantitative trait locus, Scmvl, has been identified to impart strong resistance to SCMV at the early infection stage. Here, we demonstrate that ZmTrxh, encoding an atypical h-type thioredoxin, is the causal gene at Scmvl, and that its transcript abundance correlated strongly with maize resistance to SCMV. ZmTrxh alleles, whether they are resistant or susceptible, share the identical coding/proximal promoter regions, but vary in the upstream regulatory regions. ZmTrxh lacks two canon- ical cysteines in the thioredoxin active-site motif and exists uniquely in the maize genome. Because of this, ZmTrxh is unable to reduce disulfide bridges but possesses a strong molecular chaperone-like activity. ZmTrxh is dispersed in maize cytoplasm to suppress SCMV viral RNA accumulation. Moreover, ZmTrxh- mediated maize resistance to SCMV showed no obvious correlation with the salicylic acid- and jasmonic acid-related defense signaling pathways. Taken together, our results indicate that ZmTrxh exhibits a distinct defense profile in maize resistance to SCMV, differing from previously characterized dominant or recessive potyvirus resistance genes.展开更多
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...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 （Scmvl and Scmv2） are required to confer complete resistance against SCMV in the resistant nearisogenic line F7RPJRR （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 Scmvl on chromosome 6, with R indicating a resistance allele and S a susceptibility allele） （Xing et al., 2006）.展开更多
文摘Sugarcane mosaic virus （SCMV） causes substantial losses of grain yield and forage biomass in susceptible maize worldwide. A major quantitative trait locus, Scmvl, has been identified to impart strong resistance to SCMV at the early infection stage. Here, we demonstrate that ZmTrxh, encoding an atypical h-type thioredoxin, is the causal gene at Scmvl, and that its transcript abundance correlated strongly with maize resistance to SCMV. ZmTrxh alleles, whether they are resistant or susceptible, share the identical coding/proximal promoter regions, but vary in the upstream regulatory regions. ZmTrxh lacks two canon- ical cysteines in the thioredoxin active-site motif and exists uniquely in the maize genome. Because of this, ZmTrxh is unable to reduce disulfide bridges but possesses a strong molecular chaperone-like activity. ZmTrxh is dispersed in maize cytoplasm to suppress SCMV viral RNA accumulation. Moreover, ZmTrxh- mediated maize resistance to SCMV showed no obvious correlation with the salicylic acid- and jasmonic acid-related defense signaling pathways. Taken together, our results indicate that ZmTrxh exhibits a distinct defense profile in maize resistance to SCMV, differing from previously characterized dominant or recessive potyvirus resistance genes.
文摘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 （Scmvl and Scmv2） are required to confer complete resistance against SCMV in the resistant nearisogenic line F7RPJRR （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 Scmvl on chromosome 6, with R indicating a resistance allele and S a susceptibility allele） （Xing et al., 2006）.
