Source  INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES

Published  NOV 2025

DOI: 10.1016/j.ijbiomac.2025.148059

IF  8.5

Abstract  Although Spodoptera frugiperda populations with the ryanodine receptor (RyR) I4734M mutation occurred in their native regions, this mutation has not been detected in the Eastern Hemisphere. In order to clarify the functional role of this mutation, the first HDR-mediated RyRI4734M mutation was introduced into S. frugiperda using CRISPR/Cas9 technology and a homozygous SfRyRI4734M strain was successfully established. Meanwhile, a novel, non-invasive genotyping method based on insect fecal DNA to efficiently identify genome-edited individuals was developed. Compared with the wild type, the genome-edited SfRyRI4734M strain showing high-level resistance to chlorantraniliprole (396.7-fold) and tetraniliprole (149.1-fold), and moderate resistance to cyantraniliprole (32.3-fold) and flubendiamide (29.5-fold). Reciprocal crossing experiments indicated that resistance to chlorantraniliprole was inherited in an autosomally incompletely recessive mode. Furthermore, the SfRyRI4734M substitution adversely reduced the fitness and flight ability of S. frugiperda. The mutant strain exhibited significantly decreased fecundity and severely impaired flight distance and velocity. These findings provided in vivo genetic validation of SfRyRI4734M mutation in diamide resistance, demonstrating this mutation conferred subtle differences on the binding affinities of four diamides. Moreover, our results firstly demonstrated that SfRyRI4734M mutation could affect muscle function, thereby reducing the flight ability of S. frugiperda.