Molecular Mechanisms Underlying Resistance to Bacillus thuringiensis Cry Toxins in Lepidopteran Pests: An Updated Research Perspective

Genetically modified crops that produce insecticidal proteins from Bacillus thuringiensis (Bt) are currently the most efficient and safest method of pest control worldwide. However, the prolonged planting period has led to a reduction in the efficacy of Bt crops due to the evolution of pest resistance in the field. This review paper examines the resistance status of lepidopteran pests to Bt crops under field conditions, elucidates the molecular mechanism underlying their resistance to Bt Cry toxins, and discusses resistance management strategies based on these mechanisms. Extensive research has demonstrated that mutations and alterations in expression patterns of midgut receptor genes are closely associated with Bt resistance. As our understanding of molecular mechanisms progresses, several innovative approaches such as DNA molecular detection techniques, engineering modified Cry toxins, and combining Bt toxin with RNAi technology have been developed for effective pest control measures. Future research will further unravel the intricate molecular mechanisms underlying this phenomenon to develop scientifically sound integrated pest management strategies.