Pyramiding of cry toxins and methanol producing genes to increase insect resistance in cotton

Abstract

The idea of enhanced methanol production from cell wall by pectin methyl esterase enzymes (PME) combined with expression of cry genes from Bacillus thuringiensis as a strategy to improve insect pest control in cotton is presented. We constructed a cassette containing two cry genes (cry1Fa and Cry32Aa) and two pme genes, one from Arabidopsis thaliana (AtPME), and other from Aspergillus. niger (AnPME) in pCAMBIA1301 plant expression vector using CAMV-35S promoter. This construction was transformed in Eagle-2 cotton variety by using shoot apex-cut Agrobacterium-mediated transformation. Expression of cry genes and pme genes was confirmed by qPCR. Methanol production was measured in control and in the cry and pme transformed plants showing methanol production only in transformed plants, in contrast to the non-transgenic cotton plants. Finally, insect bioassays performed with transgenic plants expressing cry and pme genes showed 100% mortality for Helicoverpa armigera (cotton bollworm) larvae, 70% mortality for Pectinophora gossypiella (pink bollworm) larvae and 95% mortality of Earias fabia, (spotted bollworm) larvae, that was higher than the transgenic plants expressing only cry genes that showed 84%, 49% and 79% mortality, respectively. These results demonstrate that Bt. cry-genes coupled with pme genes are an effective strategy to improve the control of different insect pests.

Trichomes on Cotton Leaf Surface Affect the Feeding Behaviors of Cotton Aphids

“…It's not only the leading ber source but also the third-largest eld crop in terms of edible oilseed (Ma et al 2016). Besides abiotic stresses, the cotton industry suffered serious biotic stress as well (Razzaq et al 2021). It was reported that half of the yield losses were caused by pest feeding directly and pathogenic infection indirectly (McCook and Vandermeer 2015).…”

Heterologous expression of cry3Bb1 and cry3 genes for enhanced resistance against insect pests in cotton

“…Cotton ( G. hirsutum ) is a major agro-industrial crop grown worldwide for oil and fiber purposes 1 . The production of cotton is negatively affected by both biotic and abiotic stresses 1 .…”

“…Cotton ( G. hirsutum ) is a major agro-industrial crop grown worldwide for oil and fiber purposes 1 . The production of cotton is negatively affected by both biotic and abiotic stresses 1 . Different studies suggested that insect pests and diseases bring about 15–30% yield losses, and sometimes these losses can reach up to 50% due to direct injury and plant disease transmission 2 .…”

“…The cotton fields are attacked by insect pests such as pink bollworm and army bollworm. The intensive application of chemical pesticides results in pesticide resistance in cotton pests, as well as these are also destructive to the environment and human health 1 . Pesticide applications also have negative impacts on beneficial insects 3 .…”