Effect Of Transgenic Cotton On Cotton Aphid Aphis Gossypii And Its Predator Propylea Japonica

In the past two decades, vast plantings of insect-resistant genetically modified(IRGM) crops producing insecticidal proteins from the bacterium Bacillus thuringiensis(Bt) have contributed to the management of several major insect pests and reduced the use of insecticide sprays. However, one of the risks associated with the growth of IRGM crops is their potential adverse effect on non-target arthropods(NTAs). Non-target effects assessment is one of the most important components of environmental risk assessment(ERA), which is required to authorize the IRGM crops to be released into the environment. The cotton aphid Aphis gossypii and the predator Propylaea japonica were two valued non-target arthropods. The effects of transgenic cotton and Bt proteins on Aphis gossypii and Propylaea japonica were evaluated from these aspects as follows:1 Transmission of Bt protein in the food chain “transgenic cotton – prey – predator” and its effect on the predator Propylaea japonicaTo assess the ecological effects of Bt-cotton cultivars(ZMSJ and ZMKCKC, expressing Cry1Ac/Cry2 Ab and Cry1Ac/epsps, respectively), laboratory experiments were performed to evaluate the transmission of Cry1 Ac protein in the food chain and the effects of Bt toxin on the ladybeetle predator Propylaea japonica through its herbivorous prey Aphis gossypii. Trace amounts of Cry1 Ac protein(3.0 ng/g fresh mass [FM] in ZMSJ, 3.8 ng/g FM in ZMKCKC) were detected in A. gossypii feeding on Bt cotton cultivars. Cry1 Ac protein was also detected in ladybeetles preying on Bt-fed aphids, and its quantity increased as the adult period extended(5–20 d). However, there were no distinct differences in the total developmental mortality, newly emerged adult weights, or fecundity between predators fed Bt-fed or Bt-free aphids. A delay in development was observed when P. japonica was fed A. gossypii reared on both Bt cottons. The preoviposition period was significantly longer in the ZMSJ ladybeetles than in the control ladybeetles. The poor prey quality may account for the negative effects observed in our experiment. These results suggest that the Cry1 Ac protein expressed in these transgenic cotton plants can be transmitted to predators through their herbivorous prey, but they don’t affect their biology.2 Effects of Bt proteins on the cotton aphid Aphis gossypiiPlant varieties expressing the Bt(Bacillus thuringiensis) insecticidal proteins Cry1 Ah and Cry2 Ab have potential commercialization prospects in China. However, their potential effects on non-target arthropods(NTAs) remain uncharacterized. The cotton aphid Aphis gossypii is a worldwide pest that damages various important crops. In the present study, the effects of Cry1 Ah and Cry2 Ab proteins on A. gossypii were assessed from three aspects. First, neither of the Cry proteins affected the growth or developmental characteristics of A. gossypii. Second, the expression levels of the detoxification-related genes of A. gossypii did not change significantly in either Cry protein treatment. Third, neither of the Cry proteins had a favourable effect on the expression of genes associated with the amino acid metabolism of A. gossypii. In conclusion, the Cry1 Ah and Cry2 Ab proteins do not appear to affect the cotton aphid A. gossypii.3 Bacterial communities of the cotton aphid Aphis gossypii associated with Bt cottonAphids are infected with a wide variety of endosymbionts that can confer ecologically relevant traits. Bt(cry1Ac) cotton has been planted in China for almost 20 years. However, the bacterial communities of the cotton aphid Aphis gossypii associated with Bt cotton are still poorly characterized. This study investigated the bacterial diversity of the cotton aphid Aphis gossypii associated with Bt cotton in northern China by targeting the V4 region of the 16 S r DNA using the Illumina Mi Seq platform. Our sequencing data revealed that bacterial communities of A. gossypii were generally dominated by the primary symbiont Buchnera, together with the facultative symbionts Arsenophonus and Hamiltonella. To our knowledge, this is the first report documenting the facultative symbiont Hamiltonella in A. gossypii. Moreover, the bacterial community structure was similar within aphids from the same province, but distinct among those from different provinces. The taxonomic diversity of the bacterial community is greater in Hebei Province compared with in samples from Henan and Shandong Provinces. The selection pressure exerted by the different geographical locations could explain the differences found among the various provinces.4 Effects of Bt proteins on the ladybeetle Propylea japonicaPlant varieties expressing the Bt(Bacillus thuringiensis) insecticidal proteins Cry1 Ah and Cry2 Ab have potential commercialization prospects in China. However, their potential effects on non-target arthropods(NTAs) remain uncharacterized. The ladybeetle Propylea japonica is a common and abundant natural enemy in many cropping systems in East Asia. In the present study, the effects of Cry1 Ah and Cry2 Ab proteins on P. japonica were assessed from three aspects. First, neither of the Cry proteins affected the growth or developmental characteristics of P. japonica. Second, the expression levels of the detoxification-related genes of P. japonica did not change significantly in either Cry protein treatment. Third, neither of the Cry proteins had a favourable effect on the nutrition utilization of P. japonica. In conclusion, the Cry1 Ah and Cry2 Ab proteins do not appear to affect the ladybeetle P. japonica.