Function of the ABA receptor agonist AMF4 in combination with pymetrozine for controlling Nilaparvata lugens in rice

Abstract BACKGROUND Abscisic acid (ABA), a major hormone in plants, plays a crucial role in regulating plant resistance to abiotic and biotic stresses. Unfortunately, the instability of ABA limits its application in agriculture, prompting research into ABA receptor agonists. The ABA mimic‐fluorine derivative 4 (AMF4), a fluorine derivative of ABA mimic 1, is more stable and exhibits enhanced binding affinity for pyrabactin resistance 1‐like (PYR/PYL) receptors compared with ABA. RESULTS At low concentrations, AMF4 had no effect on rice germination but slightly promoted seeding growth. AMF4 was more effective than ABA in reducing adult fecundity and nymph survival rates of brown planthopper (BPH, Nilaparvata lugens ) and in increasing callose deposition in rice stems. The synergistic ratio of AMF4 to pymetrozine against BPH was 1:120. The efficacy of the AMF4/pymetrozine mixture was validated for BPH control, and the underlying mechanisms for inducing resistance against BPH were investigated. The results indicated that using the AMF4/pymetrozine mixture enhanced thousand‐grain weight and total yield. CONCLUSIONS Overall, these findings demonstrate that AMF4 significantly enhances rice resistance to BPH, and offers significant potential for eco‐friendly BPH management in rice fields. These results are relevant to the escalating issue of insecticide resistance in BPH and provide valuable insights into developing environmentally friendly pest management strategies. © 2026 Society of Chemical Industry.