ABSTRACT
Excessive utilization of chemical pesticides for pest control can lead to adverse consequences for the health of humans and other organisms and may also cause irreversible ecological changes; therefore, the use of biologically derived insecticides can be a safe alternate strategy. Transcriptomic studies have shown JFTX- 23,a small peptide from the spider Selenocosmia jiafuis highly similar to U1-TRTX-Sp1, a well-characterized oral-effective insecticide toxin from the Australian tarantula Selenotypus plumipes. First, we evaluated the JFTX-23 peptide sequence using bioinformatics tools and modeling studies. Preliminary results showed a high similarity of JFTX-23 to JZTX-58 (91.67%) and U1-TRTX-Sp1 (86.11%). Superimposition of the α-carbons of the modeled JFTX-23 and U1-TRTX-Sp1 demonstrated a very high similarity of the 3-D structure of the two peptides (RMSD of 0.02 Å).The injection assay of JFTX-23 in Helicoverpa armigera indicated an LD50 of 0.077 and 0.423 nmol/insect after 24 and 120 h, respectively. JFTX-23 was toxic to H. armigera via oral administration with an LC50 of 1.16 nmol/g food after 5 days, which was comparable to the toxicity of the oral-effective toxin U1-TRTX-Sp1. Our studies have shown that JFTX-23 is a potent oral-effective toxin that can be considered an attractive candidate for the biological control of insect pests.
