A recent study by the Tea Plant Genetics and Breeding Innovation Team at Tea Research Institute, Chinese Academy of Agricultural Sciences (TRI CAAS) has deciphered the interaction mechanisms of interspecific insects mediated by tea plants. The findings were published in Plant, Cell & Environment.

Tea plants (Camellia sinensis) face constant threat from various herbivorous insects, which impact the growth and development of tea plants. Previous studies had demonstrated that catechin (C), epicatechin (EC), and epigallocatechin gallate (EGCG) are important insect-resistant compounds in tea plants (Li et al., 2022, Plant Cell & Environment; Lin et al., 2022 Horticulture Reasearch). However, the interaction mechanism between interspecific insects mediated by tea plants remains unclear.

This study revealed that tea plants pre-infested by the tea aphid (Toxoptera aurantia) promoted the growth of the tea geometrid (Ectropis obliqua) through an indirect, plant-mediated pathway facilitated by aphid honeydew.

Through metabolomic analysis and bioassay, the researchers identified trehalose as a key active molecule in the honeydew; while it provided no direct nutritional benefit to E. obliqua, its application (simulating honeydew concentration) suppressed the accumulation of defensive catechins in tea plants and enhanced geometrid performance.

Notably, this suppression was independent of the JA signaling pathway. Instead, trehalose induced physiological changes in tea plants, including reduced photosynthesis, stomatal conductance, and transpiration, which elevated leaf water content, creating a more favorable environment for E. obliqua growth.

The study was supported by the National Natural Science Foundation of China, the Central Public-interest Scientific Institution Basal Research Fund, and the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences.

Linkage: https://doi.org/10.1111/pce.70270

By Yongchen Yu