Fig. 5: Elevated phosphorylation of FTZ-F1 in vivo enhances resistance of P. xylostella larvae to Cry1Ac toxin.

a FTZ-F1 transcript level in the larval midgut of a susceptible DBM1Ac-S strain and four resistant P. xylostella strains. The relative expression level was quantitated and normalized to the expression level of the RPL32 gene and the value in the DBM1Ac-S strain was set as 1. b Protein expression and phosphorylation levels of FTZ-F1 in the larval midgut of the same five P. xylostella strains. Phosphorylated and non-phosphorylated FTZ-F1 proteins were separated on a Phos-tag SDS-PAGE gel, detected by anti-FTZ-F1, and quantitated by densitometry using the ImageJ 1.51 software and normalized to the β-actin. c–e Effect of FTZ-F1 silencing on phosphorylation of FTZ-F1 in the midguts (c), the transcript level of midgut genes (d), and larval susceptibility to an LC₅₀ concentration of Cry1Ac (3980 mg/L) (e) in NIL-R strain. f–h Effect of FTZ-F1 silencing on phosphorylation of FTZ-F1 in the midguts (f), the transcript level of midgut genes (g), and larval susceptibility to an LC₉₀ concentration of Cry1Ac (2 mg/L) (h) in DBM1Ac-S strain. Data were presented as mean values (n = 3) (d, g) and mean values ± SEM (n = 3) (a, e, h), ns, not significant, p values are shown. One-way ANOVA with Tukey’s test was used in a, e, h for comparison. Source data are provided as a Source Data file.