Engineering Resistance to Multiple Prunus Fruit Viruses Through Expression of Chimeric Hairpins

摘要: Prunus L. fruit production is seriously affected by several predominant viruses. The development of new cultivars resistant to these viruses challenging but highly desired breeders and growers. We report a posttranscriptional gene silencing-based approach for engineering multivirus resistance in plants. A single chimeric transgene,PTRAP6,wascreated bythe fusion 400 500-base pair (bp) fragments from six majorPrunusfruit viruses, including american plum line pattern virus, peach mosaic pox virus (PPV), prune dwarf (PDV),prunusnecroticringspotvirus,andtomatoringspotvirus(ToRSV).BothstrandsofPTRAP6werefoundbeing transcribed as an '2.5-kilobp transcript planta without splicing interruption. To induce silencing/virus resistance, weplacedtwocopiesofPTRAP6in aninverted repeatunderthecontrolofthe cauliflowermosaic virus35S promoter separated intron spacer fragment create PTRAP6i. Inoculation the resulting transgenic Nicotiana benthamiana Domin. plants revealed that 12 28 R0 PTRAP6i lines (43%) were ToRSV ranging mild symptoms symptom-free phenotypes. Detailed analysis two three homozygousR3generationlinesdemonstratedthattheywereresistanttoallthreevirusestested,includingPDV,PPV, ToRSV. remaining targeted either unavailable this study or unable systemically infect N. benthamiana. Transgene-wide -specific small interfering RNA species detected along with disappearance transgene lines, indicating silencing underlies mechanism resistance. This work presents evidence able confer multiple