State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, 311300, China; Zhejiang Provincial Key Laboratory of Forest Aromatic Plants-based Healthcare Functions, Zhejiang A&F University, Hangzhou, 311300, China.
State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, 311300, China; Zhejiang Provincial Key Laboratory of Forest Aromatic Plants-based Healthcare Functions, Zhejiang A&F University, Hangzhou, 311300, China.
Plant Physiol Biochem. 2023 May;198:107672. doi: 10.1016/j.plaphy.2023.107672. Epub 2023 Mar 30.
Isoprenoids serve important functions in protecting plant membranes against high temperature. Cinnamomum camphora is an excellent economic tree species, and releases plenty of monoterpenes. To uncover the protective mechanism of monoterpenes on the membrane system for promoting their development and utilization as anti-high temperature agents, the membrane permeability, cell ultrastructure, membrane lipid variations and related gene expression were investigated in C. camphora fumigated with camphor, one of the main monoterpenes in the plant, after fosmidomycin (Fos) blocking the monoterpene biosynthesis under high temperature (Fos+38 °C + C). High temperature at 38 °C caused the rupture of plasma as well as chloroplast and mitochondrion membranes, deformation of chloroplasts and mitochondria, and electrolyte leakage in C. camphora. High temperature with Fos treatment (Fos+38 °C) aggravated the damage, while camphor fumigation (Fos+38 °C + C) showed alleviating effects. High temperature at 38 °C disturbed the membrane lipid equilibrium by reducing the levels of 14 phosphatidylcholine, 8 phosphatidylglycerol and 6 phosphatidylethanolamine molecules, and increasing the levels of 8 phosphatidic acid, 4 diacylglycerol, 5 phosphatidylinositol, 16 sphingomyelin and 5 ceramide phosphoethanolamine molecules. Fos+38 °C treatment primarily exhibited intensifying effects on the disturbance, while these membrane lipid levels in Fos+38 °C + C5 (5 μM camphor) treatment exhibited variation tendencies to the control at 28 °C. This should result from the expression alterations of the genes related with phospholipid biosynthesis, fatty acid metabolism, and sphingolipid metabolism. It can be speculated that camphor can maintain membrane lipid stabilization in C. camphora under high temperature by acting as a signaling molecule.
类异戊二烯在保护植物膜免受高温方面起着重要作用。樟科植物是一种优良的经济树种，会释放大量的单萜。为了揭示单萜对膜系统的保护机制，以促进其作为抗高温剂的开发和利用，在福米霉素（Fos）阻断高温下单萜生物合成后，用植物中单萜之一的樟脑熏蒸樟树，研究了膜通透性、细胞超微结构、膜脂变化及相关基因表达。在 38°C 的高温下，细胞膜、叶绿体膜和线粒体膜破裂，叶绿体和线粒体变形，樟树电解质渗漏。Fos+38°C 的高温处理加剧了损伤，而樟脑熏蒸（Fos+38°C+C）则表现出缓解作用。38°C 的高温通过降低 14 种磷脂酰胆碱、8 种磷脂酰甘油和 6 种磷脂乙醇胺分子的水平，增加 8 种磷脂酸、4 种二酰基甘油、5 种磷脂酰肌醇、16 种神经鞘磷脂和 5 种神经酰胺磷酸乙醇胺分子的水平，扰乱了膜脂平衡。Fos+38°C 处理主要表现出强化干扰作用，而 Fos+38°C+C5（5μM 樟脑）处理中的这些膜脂水平表现出向 28°C 对照的变化趋势。这可能是由于与磷脂生物合成、脂肪酸代谢和神经鞘脂代谢相关的基因表达发生改变所致。可以推测，樟脑作为一种信号分子，可以在高温下维持樟树的膜脂稳定性。
