If there is an example of a silver bullet among genetically modified (GM) crops, it would be virus-resistant papaya trees. They saved the papaya industry in Hawaii from devastation by the ringspot virus, a serious pathogen that deforms fruit and eventually kills conventional trees.
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/gm-papaya-takes-ringspot-virus-and-wins
[2] http://admin.indiaenvironmentportal.org.in/category/author/erik-stokstad
[3] http://admin.indiaenvironmentportal.org.in/category/journal/science
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/agricultural-research
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/plant-breeding
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/pest-control
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/gm-crops
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/papaya
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/united-states-america-us
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/developing-countries