Flower-like Mg(OH)2 Cross Nano-sheets for Controlling Cry1Ac Protein Loss: Evaluates Its Insecticidal activity and Biosecurity

Bacillus thuringiensis (Bt) can produces Cry proteins during the sporulation phase, and Cry protein is effective against lepidopteran, coleopteran, dipteran insects and nematodes. However, Cry protein tends to be discharged into soil and non-target plants through rainwater runoff, leading to reduced effective period toward target insects. In the present study, nano-Mg(OH)2 (MHNPs) were synthesized to control the loss of Cry1Ac protein and deliver protein to Helicoverpa armigera (Lepidoptera: Noctuidae). The results showed that Cry1Ac protein could be loaded onto MHNPs through electrostatic adsorption, and both MHNPs and Cry protein were stable during the adsorption process. Meanwhile, the Cry1Ac-loaded MHNPs (designated as Cry1Ac-MHNPs) could retain on the surface of cotton leaves, resulting in enhanced adhesion amount of Cry1Ac protein by 59.50% and increased pest mortality by 75.00%. Additionally, MHNPs could be slowly decomposed by acid medium and MHNPs showed no obvious influence on the cotton, Bt, Escherichia coli and H. armigera, Therefore, MHNPs could serve as an efficient nanocarrier for delivery of Cry1Ac protein and be used as a potential adjuvant for biopesticide in agricultural applications.