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

Abstract

Transgenic technology played a crucial role in developing insect-resistant plants resulting in the reduced application of pesticides. This article reports the expression of two cry proteins (Cry3Bb1 and Cry3) in cotton for enhanced resistance against chewing insect pests. The aforementioned genes were synthetically developed and were cloned under appropriate regulatory sequences followed by transformation into Eagle-2 genotype (Gossypium hirsutum) of cotton through shoot apex-cut Agro-infiltration. The transgene integration was validated by polymerase chain reaction using primers flanking the aforementioned cry genes. Transgene expression was assessed by qRT-PCR using GADPH as a reference gene. The relative fold expression analyses revealed the highest expression of the transgene(s) in M1 plants, which is a 4.5-fold expression (Cry3 + Cry3Bb1) followed by M3 (fold expression, 3.0) (Cry3Bb1) and M2 (fold expression, 2.5) (Cry3) transformants of cotton. The confirmed transgenic plants were exposed to insect pests, pink bollworm (Pectinophora gossypiella), and army bollworm (Helicoverpa armigera). Bioassay results revealed that 60% mortality was observed against pink bollworm, and 75% mortality was observed against army bollworm in transgenic plants containing both Cry3Bb1 and Cry3 genes (M1 transgenic plants). In M2 transgenic plants containing only the Cry3Bb1 gene, the mortality was observed to be 40% in the pink bollworm population, whereas 45% mortality was observed in the army bollworm population. In the case of M3 transgenic plants containing single gene-Cry3, the mortality was 20% in the pink bollworm population, whereas 30% mortality was observed in the army bollworm population. Almost no mortality was observed in non-transgenic Eagle-2 control plants. Hence, the developed cotton transformants have improved resistance against chewing insect pests.

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

“…Upland cotton is one of the most important agro-industrial crops all around the world (Zafar et al 2022). It's not only the leading ber source but also the third-largest eld crop in terms of edible oilseed (Ma et al 2016).…”

“…It was reported that half of the yield losses were caused by pest feeding directly and pathogenic infection indirectly (McCook and Vandermeer 2015). Transgenic cotton expressing a toxic protein derived from Bacillus thuringiensis (Bt) effectively suppressed several agricultural pests such as Coleoptera, Lepidoptera, and Diptera without harming human health and the environment (Park et al 2009;Zhao et al 2016;Zafar et al 2022). With the worldwide cultivation of transgenic cotton, Helicoverpa armigera (Hübner), Pectinophora gossypiella, and some lepidopteran insects are controlled effectively, but no obvious inhibition on other insects (Helen 2006;Tabashnik 2010).…”

Comparative Analysis and Function of Multiprotein Bridging Factor1 (MBF1) Genes in Cotton

“…The negative environmental factors including drought, heat and cold stresses greatly affect the overall production of cotton Zafar et al 2021). The negative environmental factors including cold, salt, drought, heat, fungi, viruses, bacteria, nematodes and insects adversely affect plants' growth, development, productivity and quality (Mammadov et al 2018;Zafar et al 2022a;Zafar et al 2020;Zhu et al 2013). Advanced molecular techniques have been successfully implemented to reveal and understand the mechanism of plant responses and their adaptability to environmental challenges (Zhu 2002).…”

Genetic Studies in Different F2 Segregating Population for Yield and Fiber Quality Traits in Cotton (Gossypium hirsutum L.)

“…A decrease of 17.5% in cotton production was observed during last year due to biotic and abiotic factors. Cotton ginning was also declined by 12.74% due to decline in production Zafar et al 2022a;Zafar et al 2022b). Pakistan's cotton yield has been reduced in the last few years due to many reasons.…”