State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China.
State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China.
Int J Biol Macromol. 2023 Dec 31;253(Pt 2):126702. doi: 10.1016/j.ijbiomac.2023.126702. Epub 2023 Sep 4.
β-Carotene functions in plant growth and development and plays an important role in resisting abiotic stress, such as drought and salt stress. The specific function and mechanism by which β-carotene responds to waterlogging stress, however, remain elusive. In this study, we found that β-carotene content and lycopene cyclase (TgLCYB1) expression, both in leaves and roots of Torreya grandis, were increased under waterlogging treatment. Subcellular localization assays indicated that TgLCYB1 was localized in the chloroplasts. Phenotypic, physiological, and metabolome analysis showed that overexpression of TgLCYB1 enhanced the tolerance of tomato plants to waterlogging stress. Furthermore, application of a LCYB enzyme inhibitor, 2-(4-chlorophenylthio)-triethylamine hydrochloride, markedly enhanced the sensitivity of T. grandis to waterlogging stress. In addition, yeast one-hybrid assay, the dual luciferase assay system, and real-time quantitative PCR indicated that waterlogging stress induced TgWRKY22 to increase TgLCYB1 expression by binding to the TgLCYB1 promoter. Collectively, our results indicated that TgWRKY22 positively regulated TgLCYB1 expression to improve the activities of antioxidant enzyme and increase the levels of some key metabolites, thereby relieving waterlogging-induced oxidative damage, and consequently modulating the waterlogging stress response. This study contributes to a more comprehensive understanding of carotenoid functions and the role LCYB genes play in plant stress response.
β-胡萝卜素在植物的生长发育中起作用，并在抵御非生物胁迫方面发挥着重要作用，如干旱和盐胁迫。然而，β-胡萝卜素响应水淹胁迫的具体功能和机制仍不清楚。在这项研究中，我们发现β-胡萝卜素含量和番茄红素环化酶（TgLCYB1）的表达，在香榧的叶片和根部均在水淹处理下增加。亚细胞定位实验表明 TgLCYB1 定位于叶绿体。表型、生理和代谢组学分析表明，过表达 TgLCYB1 增强了番茄植株对水淹胁迫的耐受性。此外，LCYB 酶抑制剂 2-（4-氯苯基硫代）-三乙胺盐酸盐的应用显著增强了香榧对水淹胁迫的敏感性。此外，酵母单杂交试验、双荧光素酶报告基因检测系统和实时定量 PCR 表明，水淹胁迫通过与 TgLCYB1 启动子结合诱导 TgWRKY22 增加 TgLCYB1 的表达。综上所述，我们的结果表明，TgWRKY22 正向调控 TgLCYB1 的表达，以提高抗氧化酶的活性和增加一些关键代谢物的水平，从而缓解水淹诱导的氧化损伤，进而调节水淹胁迫反应。本研究有助于更全面地了解类胡萝卜素的功能以及 LCYB 基因在植物应激反应中的作用。
