RESUMEN
Two new modified Bacillus thuringiensis (Bt) proteins, Cry1Da_7 and Cry1B.868, with activity against fall armyworms (FAW), Spodoptera frugiperda (J.E. Smith), were evaluated for their potential to bind new insect receptors compared to proteins currently deployed as plant-incorporated protectants (PIPs) in row crops. Results from resistant insect bioassays, disabled insecticidal protein (DIP) bioassays, and cell-based assays using insect cells expressing individual receptors demonstrate that receptor utilizations of the newly modified Cry1Da_7 and Cry1B.868 proteins are distinct from each other and from those of commercially available Bt proteins such as Cry1F, Cry1A.105, Cry2Ab, and Vip3A. Accordingly, these two proteins target different insect proteins in FAW midgut cells and when pyramided together should provide durability in the field against this economically important pest.IMPORTANCE There is increased concern with the development of resistance to insecticidal proteins currently expressed in crop plants, especially against high-resistance-risk pests such as fall armyworm (FAW), Spodoptera frugiperda, a maize pest that already has developed resistance to Bacillus thuringiensis (Bt) proteins such as Cry1F. Lepidopteran-specific proteins that bind new insect receptors will be critical in managing current Cry1F-resistant FAW and delaying future resistance development. Results from resistant insect assays, disabled insecticidal protein (DIP) bioassays, and cell-based assays using insect cells expressing individual receptors demonstrate that target receptors of the Cry1Da_7 and Cry1B.868 proteins are different from each other and from those of commercially available Bt proteins such as Cry1F, Cry1A.105, Cry2Ab, and Vip3A. Therefore, pyramiding these two new proteins in maize will provide durable control of this economically important pest in production agriculture.
Asunto(s)
Proteínas Bacterianas/metabolismo , Endotoxinas/metabolismo , Proteínas Hemolisinas/metabolismo , Proteínas de Insectos/metabolismo , Resistencia a los Insecticidas , Spodoptera/efectos de los fármacos , Spodoptera/metabolismo , Animales , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas/genética , Proteínas Bacterianas/farmacología , Endotoxinas/genética , Endotoxinas/farmacología , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/farmacología , Proteínas de Insectos/genética , Insecticidas/metabolismo , Insecticidas/farmacología , Enfermedades de las Plantas/parasitología , Plantas Modificadas Genéticamente/parasitología , Unión Proteica , Spodoptera/genética , Zea mays/parasitologíaRESUMEN
Infection of humans by Abiotrophia defectiva, a nutritionally variant streptococcus, most commonly takes the form of endocarditis, though a variety of other manifestations ranging from central nervous system abscesses to orthopaedic infections have been seen. We report here what we believe is the first case of bullous impetigo associated with this organism.
