Regional environment variations and management practices likely influence gut gene expression in Bt-resistant pink bollworm (Pectinophora gossypiella) from the northern and southern parts of India

Abstract Currently, of the 29 countries that grow Bt cotton, India has reported field-evolved resistance to the Bacillus thuringiensis dual toxin (Cry1Ac and Cry2Ab) in Pectinophora gossypiella, a major global pest. Understanding the fundamental reasons & mechanisms of this resistance is critically important. To date, there has been only one transcriptome study that reported the gut mRNA profiling of resistant pink bollworms from the southern agri-ecological zone. In this study, we present the midgut transcriptome of pink bollworm populations that are field-resistant, collected from the northern agri-ecological zone. A comparative analysis of the transcriptomes from resistant insect populations in both cotton-growing regions showed distinct patterns of gene expression, particularly for digestive proteases such as trypsin, chymotrypsin, and aminopeptidases, as well as α-arylphorin, aquaporins, cadherins, and the circadian clock-controlled protein, daywake-like (dyw). Additional validation has confirmed the upregulation of the dyw transcript in pink bollworm larvae gathered from cotton stubble. These findings indicate that variations in regional climate, soil composition, cropping systems, and management strategies can affect pest resistance at a molecular level. This research will not only enhance our understanding of how pink bollworms resist dual Bt toxins but also emphasize the necessity for region-specific integrated pest management approaches and resistant gene markers to maintain this technology.