Genome-wide Identification and Functional Analysis of Kunitz-Type Trypsin InhibitorGene Family in Cotton against Pest Resistance

The proteinase inhibitors, such as Kunitz-type inhibitors (KTI), play a vital role in increasing pest resistance in genetically engineered crops.The KTI genes encode proteinase inhibitors known to confer resistance to major pests such as cotton bollworm and whiteflies.This study aims to comprehensively investigate the cotton genome-wide Kunitz Trypsin Inhibitor (KTI) gene family and assess its role in contributing to improving insect pest resistance.A total of 18 KTI genes were identified across three cotton species: Gossypium hirsutum, Gossypium arboreum, and Gossypium raimondii.The genomic structure, evolutionary relationships, and functional implications of these genes were analyzed using advanced bioinformatics tools.The agarose gel electrophoresis confirmed the integrity of the extracted DNA, ensuring the reliability of the analyses.The key genes with differential expression were identified using qRT-PCR.A qRT-PCR analysis was performed on selected genes, including GH_A05G4127.1,GH_D04G0257.1,GH_A05G4126.1 and GH_D04G0256.1 for computational predictions.The results showed that the GH_A05G4127.1 gene exhibited 5-fold relative expression, whereas the other three genes were downregulated compared with the control.This research represents a significant step in characterizing KTI gene function in cotton and demonstrates its potential in conferring insect resistance.The findings contribute to the development of pestresilient cotton cultivars, offering promising applications for sustainable agriculture.