Evaluating the Effect of RNA Interference of X-Box Binding Protein 1 (XBP1) on Survival and Fecundity in Acyrthosiphon pisum

Acyrthosiphon pisum (pea aphid) is a major pest of Fabaceae (legume) crops, causing direct feeding damage and transmitting plant viruses. Conventional control relies on broad-spectrum insecticides and natural enemies, both of which can harm non-target organisms and ecosystems. RNA interference (RNAi) offers a promising, species-specific alternative by silencing essential genes via double-stranded RNA (dsRNA). This study targeted X-Box Binding Protein 1 (XBP1), a key transcription factor in the Unfolded Protein Response (UPR) pathway that regulates proper protein folding in the Endoplasmic Reticulum (ER). This chaperone promotes folding of newly synthesized polypeptides and helps manage misfolded proteins. Silencing the XBP1 gene was hypothesized to cause accumulation of misfolded proteins in the ER lumen, triggering ER stress, UPR overload and ultimately apoptosis, leading to aphid mortality. Total RNA was extracted from adult pea aphids, reverse-transcribed to cDNA and used to synthesize gene-specific dsRNA for XBP1. The dsRNA was conjugated to Branched-Amphiphilic Peptide Capsules (BAPCs) and delivered orally at concentrations of 1, 10 and 100 ng/µL via artificial diet feeding in parafilm-layered petri dishes. Fecundity and survival were monitored at regular intervals. Results demonstrated a fifty percent decrease in fecundity and a thirty percent decrease in survival in the 100 ng/µL treatment groups compared to controls (log-rank test), supporting the induction of apoptosis. This approach highlights the potential of UPR-targeted RNAi for eco-friendly, targeted pest control of A. pisum.