Spicher Livia, Glauser Gaetan, Kessler Felix
Laboratory of Plant Physiology, Institute of Biology, University of Neuchâtel Neuchâtel, Switzerland.
Neuchâtel Platform of Analytical Chemistry, University of Neuchâtel Neuchâtel, Switzerland.
Front Plant Sci. 2016 Feb 17;7:167. doi: 10.3389/fpls.2016.00167. eCollection 2016.
Increased temperatures are a major scenario in climate change and present a threat to plant growth and agriculture. Plant growth depends on photosynthesis. To function optimally, the photosynthetic machinery at the thylakoid membrane in chloroplasts continuously adapts to changing conditions. Here, we set out to discover the most important changes arising at the lipid level under high temperature (38°C) in comparison to mild (20°C) and moderately cold temperature (10°C) using a non-targeted lipidomics approach. To our knowledge, no comparable experiment at the level of the whole membrane system has been documented. Here, 791 molecular species were detected by mass spectrometry and ranged from membrane lipids, prenylquinones (tocopherols, phylloquinone, plastoquinone, plastochromanol), carotenoids (β-carotene, xanthophylls) to numerous unidentified compounds. At high temperatures, the most striking changes were observed for the prenylquinones (α-tocopherol and plastoquinone/-ol) and the degree of saturation of fatty acids in galactolipids and phosphatidyl ethanolamine. Photosynthetic efficiency at high temperature was not affected but at moderately cold temperature mild photoinhibition occurred. The results indicate, that the thylakoid membrane is remodeled with regard to fatty acid saturation in galactolipids and lipid antioxidant concentrations under high temperature stress. The data strongly suggest, that massively increased concentrations of α-tocopherol and plastoquinone are important for protection against high temperature stress and proper function of the photosynthetic apparatus.
气温升高是气候变化的一个主要情形，对植物生长和农业构成威胁。植物生长依赖光合作用。为了实现最佳功能，叶绿体类囊体膜上的光合机制会不断适应变化的条件。在此，我们采用非靶向脂质组学方法，旨在发现与温和温度（20°C）和中度低温（10°C）相比，高温（38°C）下脂质水平出现的最重要变化。据我们所知，尚未有关于整个膜系统层面的可比实验记录。通过质谱法检测到791种分子种类，范围从膜脂、异戊二烯醌（生育酚、叶绿醌、质体醌、质体色素醇）、类胡萝卜素（β-胡萝卜素、叶黄素）到众多未鉴定的化合物。在高温下，异戊二烯醌（α-生育酚和质体醌/质体酚）以及半乳糖脂和磷脂酰乙醇胺中脂肪酸的饱和度变化最为显著。高温下光合效率未受影响，但在中度低温下出现了轻度光抑制。结果表明，在高温胁迫下，类囊体膜在半乳糖脂的脂肪酸饱和度和脂质抗氧化剂浓度方面发生了重塑。数据有力地表明，α-生育酚和质体醌浓度大幅增加对于抵御高温胁迫和光合装置的正常功能很重要。
