Microbiology and Biotechnology Research: An Overview Vol. 10

Crop protection is under simultaneous pressure from persistent yield losses to arthropods and pathogens, the attrition of conventional active ingredients through resistance and regulatory withdrawal, and rising expectations that pest management should be selective and environmentally defensible. Two biologically programmable modalities have moved furthest towards meeting those expectations: exogenously applied or plant-expressed double-stranded ribonucleic acid, which silences pest or pathogen genes through the RNA interference pathway, and peptide-based agents, which include insecticidal venom-derived peptides, antimicrobial and defence-eliciting peptides, and engineered peptide carriers. This review critically evaluates the two modalities together rather than separately, on the argument that they now share the same translational bottlenecks and are increasingly deployed as a single formulation. The literature was assembled through structured searching of open bibliographic and scholarly indexes to a defined final search date, with every retained source verified against publisher metadata. The synthesis indicates that the strongest evidence for either modality remains concentrated in a small number of pest systems, principally coleopteran defoliators and root feeders for RNA interference and a small number of venom-derived and antimicrobial peptide systems for the peptide modality, and that extrapolation beyond those systems is not well supported. Efficacy variation across taxa is now attributable to identifiable and partly tractable barriers, including extracellular nucleases, endosomal entrapment and tissue-dependent uptake, rather than to unexplained species idiosyncrasy. Resistance has been selected under laboratory conditions for double-stranded RNA and has emerged in the field for related protein-based actives, which weakens the assumption that sequence-programmable actives are intrinsically durable. Environmental fate data indicate rapid dissipation of applied nucleic acid in soil, while non-target evidence remains dominated by short-term, single-species assays. The principal unresolved questions concern field-scale dose–response relationships, the durability of both modalities under realistic selection, and the cost structures that determine whether either becomes accessible outside high-value cropping. Confidence in current conclusions is constrained by the concentration of evidence in a few laboratories, crops and regions.