# Mowing Enhances Insect Resistance in Glycyrrhiza uralensis by Reprogramming Volatile Profiles and Inducing Flavonoid Accumulation

## TL;DR

Mowing licorice plants makes them less attractive to whiteflies and boosts their natural defenses through changes in chemical signals and increased flavonoid production.

## Contribution

This study reveals that mowing enhances plant resistance to whiteflies by reprogramming volatile profiles and inducing flavonoid accumulation in licorice.

## Key findings

- Mowed licorice plants repel whiteflies by emitting more terpenoids and fewer attractant alcohols.
- Mowing increases flavonoid accumulation, which slows whitefly development and strengthens plant defenses.
- Transcriptomic and metabolomic analyses show mowing activates defense-related pathways in licorice.

## Abstract

Whiteflies (Bemisia tabaci) are serious pests that damage many crops, including licorice (Glycyrrhiza uralensis). Finding environmentally friendly ways to reduce whitefly infestation is therefore important for sustainable agriculture. In this study, we examined whether mowing, a simple cultural practice, could enhance licorice resistance to whiteflies. We found that whiteflies strongly preferred unmowed plants, while mowed plants were less attractive. Mowing changed the chemical signals released by plants, reducing compounds that attract whiteflies and increasing terpenoids that repel them. In addition, mowed plants accumulated higher levels of defensive flavonoids after whitefly feeding. As a result, whiteflies developed more slowly on mowed plants. These findings show that mowing can naturally strengthen plant defenses against insect pests. Our study highlights mowing as a low-cost and eco-friendly strategy that could help reduce pesticide use in licorice cultivation and other cropping systems.

Mowing is a widely used agricultural management practice, yet its role in shaping plant–insect interactions remains largely unexplored. In this study, we investigated how mowing influences resistance of licorice (Glycyrrhiza uralensis) to the whitefly Bemisia tabaci by integrating behavioral assays with volatile analysis, transcriptomics, and metabolomics. Feeding preference assays showed that adult whiteflies strongly preferred new plants over mowed plants. Developmental assays further revealed that whiteflies exhibited a prolonged egg stage and extended egg-to-adult developmental duration on mowed plants, while adult longevity was not significantly affected. Gas chromatography–mass spectrometry analysis identified 31 volatile compounds in licorice, with alcohols dominating the volatile profile of new plants and terpenoids dominating that of mowed plants. Whitefly infestation significantly increased ester compounds in both plant types. Differential volatile analysis highlighted cis-3-hexen-1-ol and trans-3-hexen-1-ol as dominant compounds in new plants, whereas 3-carene and β-pinene were predominant in mowed plants. Transcriptomic analysis revealed that mowing primarily affected genes associated with primary metabolism and ribosome-related pathways, whereas whitefly infestation induced extensive transcriptional reprogramming, including activation of flavonoid biosynthesis, flavone and flavonol biosynthesis, MAPK signaling, and plant circadian rhythm pathways. Metabolomic profiling identified substantial accumulation of flavonoids, flavonols, and isoflavonoids following whitefly feeding. Integrated multi-omics analysis identified flavonol biosynthesis as a core pathway underlying licorice defense against B. tabaci. Overall, this study demonstrates that mowing primes G. uralensis for enhanced resistance to whitefly infestation by reshaping volatile emissions, activating secondary metabolite biosynthesis, and inducing coordinated defense signaling networks. These findings provide new insights into plant–insect interactions and highlight mowing as a potential component of sustainable pest management strategies.