Expression of Bt Protein in Transgenic Bt Cotton Plants and Ecological Fitness of These Plants in Different Habitats

Abstract

Fitness is one of the key parameters to evaluate the effects of transgenic plants on the ecological environment. To evaluate the ecological risk of transgenic Bt cotton plants growing in different habitats, we determined the expression of the exogenous Bt gene and the fitness of transgenic and non-transgenic cotton plants in three habitats (farmland, grassland, and shrub). We observed that the expression of Bt protein in the farmland was significantly higher than that in the natural habitat, and when the growth environment was suitable, the Bt protein expression level showed a downward trend with the advancement of the growth. There were no significant differences in plant height, aboveground biomass, and seed yield between the Bt transgenic and non-transgenic cotton plants at the same growth stage under the same habitat. Nevertheless, in different habitats, the fitness of the same cotton line showed significant differences. In the farmland habitat, the plant height, aboveground biomass, and seed yield of both transgenic cotton and its non-transgenic isoline were significantly higher than that in the other two natural habitats. The results indicate that the expression of Bt protein does not increase the fitness of the parent plants and would not cause the weeding of the recipient cotton plants.

Diverse genetic basis of Vip3Aa resistance in five independent field‐derived strains of Helicoverpa zea in the US

“…frugiperda calculated by Jin et al 46 . was based on a Vip3Aa concentration of 0.4 μg cm −2 , which is lower than the concentration typically produced by Bt corn and cotton plants 47–50 . Previous studies show that the degree of dominance varies based on Bt concentrations, with nonrecessive resistance at low concentration and more recessive resistance at high concentrations 23,51 .…”

“…46 However, this degree of dominance in S. frugiperda calculated by Jin et al 46 was based on a Vip3Aa concentration of 0.4 μg cm −2 , which is lower than the concentration typically produced by Bt corn and cotton plants. [47][48][49][50] Previous studies show that the degree of dominance varies based on Bt concentrations, with nonrecessive resistance at low concentration and more recessive resistance at high concentrations. 23,51 Resistance to Vip3Aa in strains of Helicoverpa punctigera and Helicoverpa armigera from Australia also was monogenic and essentially recessive.…”

A comparative study of transgenic cotton development, impacts, challenges and prospects with respect to China and Africa

“…Bt cotton growing in different habitats (farmland, grassland and shrubs) were assessed for fitness level. It was found that the expression of Bt protein in the farmland was significantly higher than that in the other habitats (Liu et al, 2020).…”

“…Fitness is also one of the key parameters to evaluate the effects of transformed plants on the ecological environment (Liu et al, 2020). Bt cotton growing in different habitats (farmland, grassland and shrubs) were assessed for fitness level.…”

Alterations in Growth Habit to Channel End-of-Season Perennial Reserves towards Increased Yield and Reduced Regrowth after Defoliation in Upland Cotton (Gossypium hirsutum L.)

“…Each accession was grown in two 40 feet rows where individual plants were space planted with a 1-foot plant-to-plant and row-to-row distance. As stated, the experiment was performed at the same field location for three years to avoid, as much as possible, edaphic, management, and ecological variabilities (insect pest and pathogen pressure), as the gene expression traits were shown earlier to be highly influenced by these factors [ 86 ]. Three plants, specifically somewhat from the center of the two rows showing the characteristics of specific genotypes, were tagged and used for taking plant samples to serve as three biological replicates in the experiment.…”