Bt resistance in fall armyworm: Diversity in cross-resistance, inheritance, and fitness costs

2016 ◽  
Author(s):  
Fangneng Huang
Keyword(s):  
Fall Armyworm ◽  
Cross Resistance ◽  
Fitness Costs ◽  
Bt Resistance ◽  
Resistance Inheritance

Cross-resistance and lack of fitness costs occurred in the cyantraniliprole-resistant oriental fruit fly

2021 ◽  
Author(s):  
Zhang Ruimin ◽  
He Shiyu ◽  
Zeng Jiwu ◽  
Chen Jiahua ◽  
Dong Junfeng
Keyword(s):  
Fruit Fly ◽  
Cross Resistance ◽  
Oriental Fruit Fly ◽  
Fitness Costs

scholarly journals Characterization of Chimeric Bacillus thuringiensis Vip3 Toxins

2006 ◽  
Vol 73 (3) ◽  
pp. 956-961 ◽  
Author(s):  
Jun Fang ◽  
Xiaoli Xu ◽  
Ping Wang ◽  
Jian-Zhou Zhao ◽  
Anthony M. Shelton ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Trichoplusia Ni ◽  
European Corn Borer ◽  
Insect Pest ◽  
Chimeric Protein ◽  
Fall Armyworm ◽  
Terminal Region ◽  
Cabbage Looper ◽  
Cross Resistance ◽  
Corn Borer

ABSTRACT Bacillus thuringiensis vegetative insecticidal proteins (Vip) are potential alternatives for B. thuringiensis endotoxins that are currently utilized in commercial transgenic insect-resistant crops. Screening a large number of B. thuringiensis isolates resulted in the cloning of vip3Ac1. Vip3Ac1 showed high insecticidal activity against the fall armyworm Spodoptera frugiperda and the cotton bollworm Helicoverpa zea but very low activity against the silkworm Bombyx mori. The host specificity of this Vip3 toxin was altered by sequence swapping with a previously identified toxin, Vip3Aa1. While both Vip3Aa1 and Vip3Ac1 showed no detectable toxicity against the European corn borer Ostrinia nubilalis, the chimeric protein Vip3AcAa, consisting of the N-terminal region of Vip3Ac1 and the C-terminal region of Vip3Aa1, became insecticidal to the European corn borer. In addition, the chimeric Vip3AcAa had increased toxicity to the fall armyworm. Furthermore, both Vip3Ac1 and Vip3AcAa are highly insecticidal to a strain of cabbage looper (Trichoplusia ni) that is highly resistant to the B. thuringiensis endotoxin Cry1Ac, thus experimentally showing for the first time the lack of cross-resistance between B. thuringiensis Cry1A proteins and Vip3A toxins. The results in this study demonstrated that vip3Ac1 and its chimeric vip3 genes can be excellent candidates for engineering a new generation of transgenic plants for insect pest control.

Fitness costs of Cry1F resistance in fall armyworm, Spodoptera frugiperda

2013 ◽  
Vol 138 (5) ◽  
pp. 315-325 ◽  
Author(s):  
A. M. Vélez ◽  
T. A. Spencer ◽  
A. P. Alves ◽  
A. L. B. Crespo ◽  
B. D. Siegfried
Keyword(s):  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
Fitness Costs

scholarly journals Frequency, Spectrum, and Nonzero Fitness Costs of Resistance to Myxopyronin in Staphylococcus aureus

2012 ◽  
Vol 56 (12) ◽  
pp. 6250-6255 ◽  
Author(s):  
Aashish Srivastava ◽  
David Degen ◽  
Yon W. Ebright ◽  
Richard H. Ebright
Keyword(s):  
Staphylococcus Aureus ◽  
Binding Site ◽  
Frequency Spectrum ◽  
Resistance Rate ◽  
Cross Resistance ◽  
Β Subunit ◽  
Fitness Costs ◽  
Switch Region ◽  
Content Type ◽  
Resistant Mutants

ABSTRACTThe antibiotic myxopyronin (Myx) functions by inhibiting bacterial RNA polymerase (RNAP). The binding site on RNAP for Myx—the RNAP “switch region SW1/SW2 subregion”—is different from the binding site on RNAP for the RNAP inhibitor currently used in broad-spectrum antibacterial therapy, rifampin (Rif). Here, we report the frequency, spectrum, and fitness costs of Myx resistance inStaphylococcus aureus. The resistance rate for Myx is 4 × 10−8to 7 × 10−8per generation, which is equal within error to the resistance rate for Rif (3 × 10−8to 10 × 10−8per generation). Substitutions conferring Myx resistance were obtained in the RNAP β subunit [six substitutions: V1080(1275)I, V1080(1275)L, E1084(1279)K, D1101(1296)E, S1127(1322)L, and S1127(1322)P] and the RNAP β′ subunit [five substitutions: K334(345)N, T925(917)K, T925(917)R, G1172(1354)C, and G1172(1354)D] (residues numbered as inStaphylococcus aureusRNAP and, in parentheses, as inEscherichia coliRNAP). Sites of substitutions conferring Myx resistance map to the RNAP switch region SW1/SW2 subregion and do not overlap the binding site on RNAP for Rif, and, correspondingly, Myx-resistant mutants exhibit no cross-resistance to Rif. All substitutions conferring Myx resistance exhibit significant fitness costs (4 to 15% per generation). In contrast, at least three substitutions conferring Rif resistance exhibit no fitness costs (≤0% per generation). The observation that all Myx-resistant mutants have significant fitness costs whereas at least three Rif-resistant mutants have no fitness costs, together with the previously established inverse correlation between fitness cost and clinical prevalence, suggests that Myx resistance is likely to have lower clinical prevalence than Rif resistance.

scholarly journals Geographic Monitoring of Insecticide Resistance Mutations in Native and Invasive Populations of the Fall Armyworm

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 468
Author(s):  
Sudeeptha Yainna ◽  
Nicolas Nègre ◽  
Pierre J. Silvie ◽  
Thierry Brévault ◽  
Wee Tek Tay ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Fall Armyworm ◽  
Sub Saharan Africa ◽  
Pest Species ◽  
Resistance Mutations ◽  
Chinese Populations ◽  
Bt Resistance ◽  
Native Populations ◽  
Sub Saharan ◽  
Lepidopteran Pest

Field evolved resistance to insecticides is one of the main challenges in pest control. The fall armyworm (FAW) is a lepidopteran pest species causing severe crop losses, especially corn. While native to the Americas, the presence of FAW was confirmed in West Africa in 2016. Since then, the FAW has been detected in over 70 countries covering sub-Saharan Africa, the Middle East, North Africa, South Asia, Southeast Asia, and Oceania. In this study, we tested whether this invasion was accompanied by the spread of resistance mutations from native to invasive areas. We observed that mutations causing Bt resistance at ABCC2 genes were observed only in native populations where the mutations were initially reported. Invasive populations were found to have higher gene numbers of cytochrome P450 genes than native populations and a higher proportion of multiple resistance mutations at acetylcholinesterase genes, supporting strong selective pressure for resistance against synthetic insecticides. This result explains the susceptibility to Bt insecticides and resistance to various synthetic insecticides in Chinese populations. These results highlight the necessity of regular and standardized monitoring of insecticide resistance in invasive populations using both genomic approaches and bioassay experiments.

Sign in / Sign up

Export Citation Format

Share Document