CED4 and CED4-like Peptides as Effective Plant Parasitic Nematicides

Plant parasitic nematodes are a significant agricultural threat, causing substantial economic losses. Methyl bromide, a commonly used nematicide, has been banned due to its harmful environmental and human health effects. As an alternative, the expression of the programmed cell death (PCD) gene CED4 from Caenorhabditis elegans in transgenic plants has been proposed to control nematode populations. In this study, the interaction between CED4 and other proteins was analyzed, and peptide sequences representing interaction domains were identified. Efficacy assays demonstrated that specific peptides—particularly Peptides 2 and 3 (N-terminal α/β domain) and Peptide 12 (C-terminal HD-2 domain)—induced significant mortality in C. elegans, while other peptides were ineffective. The study further investigated whether these peptides, along with modified CED4-like peptides (2a, 3a, and 12a), induce PCD in C. elegans via the activation of the nematode’s endogenous PCD pathway. Testing was conducted on wild-type and mutant strains of C. elegans (ced-4 and ced-3 mutants). Nematode survival was monitored over 34 days, revealing that c3 mutants survived exposure to CED4-like peptides, suggesting that the peptides trigger PCD through the activation of the endogenous cell death pathway. These findings support the potential use of CED4-based peptides as a novel strategy for nematode control.