Abstract: Microtus fortis prefers to feed on the leaves of Broussonetia papyrifera, which would inhibit its reproduction. We focused on the key gene BpMYB56 in B. papyrifera that responds to rodent feeding, constructed BpMYB56 overexpressing B. papyrifera (OE1-OE3), and compared their nutritional differences with wild-type B. papyrifera (WT). We evaluated the attractiveness of overexpressing B. papyrifera leaves to the M. fortis and their effects on body weight and organs when mixed with typical rodent sterilants, such as α-chlorohydrin, curcumol, and tripto-lide, at a ratio of 50:1. The results showed that the contents of crude protein, crude fat, crude fiber, crude ash, soluble sugar, Ca, Fe, P, and total flavonoids in the leaves of overexpressing B. papyrifera were all higher than those in WT. Among the lines, OE3 exhibited the highest content for each component, being 1.2, 1.1, 1.3, 1.1, 1.6, 1.2, 1.1, 1.4, and 1.2 times those of WT, respectively. Except for crude ash, all differences reached a signifi-cant level. The feeding trial results showed that under free-choice conditions, the attraction time of fresh OE3 leaves to female and male M. fortis were 1.9 and 1.8 times those of WT, and the single-attraction time were 1.4 and 1.7 times those of WT, respectively. However, for dried OE3 leaves, there were no significant differences in attraction time, attraction frequency, or single-attraction time compared with dried WT. Among the combinations of OE3 leaves with sterilants, the curcumol+OE3 group exhibited the best attractant effect, which was 3.1 times that of the WT group. None of the different combinations had a significant effect on body weight of M. fortis. Both the testicular index and testicular volume of male M. fortis only in the triptolide+OE3 combination were significantly lower than those in the WT group. Overexpression of BpMYB56 influenced the accumulation of nutrients and flavonoids in B. papyrifera leaves, thereby altering their attractiveness to M. fortis, particularly for fresh leaves. However, the attractiveness of the overexpression lines when combined with different types of rodent contraceptives varied, showing drug- and sex-specific effects.

Key words: chemosterilant, plant-animal interaction, rodent pest control, rodent attraction