CsAFS2 Gene from the Tea Plant Intercropped with Chinese Chestnut Plays an Important Role in Insect Resistance and Cold Resistance

Abstract

α-Farnesene, a crucial secondary metabolite in sesquiterpenes, is crucial for plant biotic and abiotic stress resistance. In this study, we screened an AFS gene from transcriptome data of tea plants (Camellia sinensis) intercropped with Chinese chestnut (Castanea mollissima), resulting in the cloning of CsAFS2. CsAFS2 expression increased following treatment with MJ (Methyl jasmonate), SA (Salicylic acid), GA3 (Gibberellin A3), and various plant growth regulators, as well as under high-salt, drought, and low-temperature conditions. The heterologous genetic transformation of tobacco with CsAFS2 led to an enhanced resistance to low-temperature stress and aphid feeding, evident from elevated levels of osmotic regulatory substances, increased protective enzyme activity, and the upregulation of cold and insect resistance-related genes. Trichomes, crucial in cold and insect resistance, exhibited significantly greater length and density in transgenic tobacco as compared to control plants. These results confirm the vital role of CsAFS2 in enhancing cold and insect resistance, providing comprehensive insights into stress regulation mechanisms in tea plants and advancing stress-resistant tea plant breeding.