Eugenol functions as a signal mediating cold and drought tolerance via UGT71A59‐mediated glucosylation in tea plants. (4th February 2022)

• Record Type: Journal Article
• Authors: Zhao, Mingyue; Jin, Jieyang; Wang, Jingming; Gao, Ting; Luo, Yu; Jing, Tingting; Hu, Yutong; Pan, Yuting; Lu, Mengqian; Schwab, Wilfried; Song, Chuankui
• Is Part Of: Plant journal. Volume 109:Number 6(2022)
• Page Start: 1489
• Page End: 1506
• Publication Date: 2022-02-04
• Subjects: eugenol -- glucosyltransferase -- glucosylation -- tea plants -- Camellia sinensis -- cold stress -- drought stress; Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.15647
• Languages: English
• ISSNs: 0960-7412

Abstract

SUMMARY: Cold and drought stress are the most critical stresses encountered by crops and occur simultaneously under field conditions. However, it is unclear whether volatiles contribute to both cold and drought tolerance, and if so, by what mechanisms they act. Here, we show that airborne eugenol can be taken up by the tea ( Camellia sinensis ) plant and metabolized into glycosides, thus enhancing cold and drought tolerance of tea plants. A uridine diphosphate (UDP)‐glucosyltransferase, UGT71A59, was discovered, whose expression is strongly induced by multiple abiotic stresses. UGT71A59 specifically catalyzes glucosylation of eugenol glucoside in vitro and in vivo . Suppression of UGT71A59 expression in tea reduced the accumulation of eugenol glucoside, lowered reactive oxygen species (ROS) scavenging capacity, and ultimately impaired cold and drought stress tolerance. Exposure to airborne eugenol triggered a marked increase in UGT71A59 expression, eugenol glucoside accumulation, and cold tolerance by modulating ROS accumulation and CBF1 expression. It also promoted drought tolerance by altering abscisic acid homeostasis and stomatal closure. CBF1 and CBF3 play positive roles in eugenol‐induced cold tolerance and CBF2 may be a negative regulator of eugenol‐induced cold tolerance in tea plants. These results provide evidence that eugenol functions as a signal in cold and drought tolerance regulation and shed new light on the biological functions of volatiles in the response to multiple abiotic stresses in plants. Significance Statement: The volatile eugenol functions as a signal and plays a positive role in cold stress through regulating reactive oxygen species accumulation and CBF1 expression and in drought stress through altering abscisic acid homeostasis and stomatal closure via UDP‐glucosyltransferase UGT71A59‐mediated eugenol glucosylation in tea ( Camellia sinensis ) plants.