Btderived

Bt-derived refers to substances, products, or organisms derived from Bacillus thuringiensis, a soil bacterium used as a biological control agent against insect pests. The most widely employed Bt-derived toxins are crystal proteins produced during sporulation, known as Cry toxins, along with Cyt toxins. These proteins are insecticidal when ingested by susceptible larvae and are often formulated as microbial sprays or expressed in crops.

Cry toxins are activated in the alkaline gut of target insects, bind to gut epithelial receptors, form pores, and cause cell lysis and larval death. Specificity arises from receptor presence, resulting in a narrow host range for many Cry proteins. The action is typically limited to certain Lepidoptera, Coleoptera, or Diptera groups, depending on the toxin.

Bt-derived products are used as foliar sprays, soil drenches, and dry formulations for pest control. In agriculture, crops are genetically engineered to express Bt Cry proteins, reducing pest damage and enabling reduced chemical insecticide use. Bt crops include varieties engineered for corn and cotton, among others, often employing pyramiding strategies that combine multiple toxins to delay resistance.

Bt-derived products are generally considered safe for humans and many non-target organisms when used as directed. Regulatory agencies evaluate efficacy, specificity, and environmental impact before approval. Resistance management programs emphasize refuges and monitoring for resistant pests.

Pests can evolve resistance to Bt toxins, and non-target effects, while typically low, require ongoing assessment. Integration with other integrated pest management practices enhances sustainability.