Herbivore-Induced (Z)‑3-Hexen-1-ol is an Airborne Signal That Promotes Direct and Indirect Defenses in Tea (Camellia sinensis) under Light

• Published in: Journal of agricultural and food chemistry Vol. 69; no. 43; pp. 12608 - 12620
• Main Authors: Liao, Yinyin, Tan, Haibo, Jian, Guotai, Zhou, Xiaochen, Huo, Luqiong, Jia, Yongxia, Zeng, Lanting, Yang, Ziyin
• Format: Journal Article
• Language: English
• Published: American Chemical Society 03.11.2021
• Subjects: Agricultural and Environmental Chemistry; tea; Camellia sinensis; (Z)-3-hexen-1-ol; signaling; defense; glycosylation; volatile
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/acs.jafc.1c04290

Tea (Camellia sinensis) is the most popular nonalcoholic beverage worldwide. During cultivation, tea plants are susceptible to herbivores and pathogens, which can seriously affect tea yield and quality. A previous report showed that (Z)-3-hexenol is a potentially efficient defensive substance. However, the molecular mechanism mediating (Z)-3-hexenol signaling in tea plants and the resulting effects on plant defenses remain uncharacterized. To clarify the signaling mechanisms in which (Z)-3-hexenol and light are involved, the gene transcription and metabolite levels were assessed, respectively. This study demonstrated that tea plants rapidly and continuously release (Z)-3-hexen-1-ol in response to an insect infestation. (Z)-3-Hexen-1-ol absorbed by adjacent healthy plants would be converted into three insect defensive compounds: (Z)-3-hexenyl-glucoside, (Z)-3-hexenyl-primeveroside, and (Z)-3-hexenyl-vicianoside identified with laboratory-synthesized standards. Moreover, (Z)-3-hexen-1-ol also activates the synthesis of jasmonic acid to enhance the insect resistance of tea plants. Additionally, a continuous light treatment induces the accumulation of (Z)-3-hexenyl-glycosides. Hence, (Z)-3-hexenol serves as a light-regulated signaling molecule that activates the systemic defenses of adjacent plants. Our study reveals the molecular mechanisms by which biotic and abiotic factors synergistically regulate the signaling functions of herbivore-induced plant volatiles in plants, providing valuable information for future comprehensive analyses of the systemic defense mechanisms in plants.