Shiva Sunitha, Samarakoon Thilani, Lowe Kaleb A, Roach Charles, Vu Hieu Sy, Colter Madeline, Porras Hollie, Hwang Caroline, Roth Mary R, Tamura Pamela, Li Maoyin, Schrick Kathrin, Shah Jyoti, Wang Xuemin, Wang Haiyan, Welti Ruth
Division of Biology, Kansas State University, Ackert Hall, Manhattan, KS 66506-4901, USA.
Department of Biological Sciences, University of North Texas, Denton, TX 76203-5017, USA.
Plants (Basel). 2020 Jul 4;9(7):845. doi: 10.3390/plants9070845.
In response to elevated temperatures, plants alter the activities of enzymes that affect lipid composition. While it has long been known that plant leaf membrane lipids become less unsaturated in response to heat, other changes, including polygalactosylation of galactolipids, head group acylation of galactolipids, increases in phosphatidic acid and triacylglycerols, and formation of sterol glucosides and acyl sterol glucosides, have been observed more recently. In this work, by measuring lipid levels with mass spectrometry, we confirm the previously observed changes in leaf lipids under three heat stress regimens. Additionally, in response to heat, increased oxidation of the fatty acyl chains of leaf galactolipids, sulfoquinovosyldiacylglycerols, and phosphatidylglycerols, and incorporation of oxidized acyl chains into acylated monogalactosyldiacylglycerols are shown. We also observed increased levels of digalactosylmonoacylglycerols and monogalactosylmonoacylglycerols. The hypothesis that a defect in sterol glycosylation would adversely affect regrowth of plants after a severe heat stress regimen was tested, but differences between wild-type and sterol glycosylation-defective plants were not detected.
作为对温度升高的响应，植物会改变影响脂质组成的酶的活性。虽然早就知道植物叶片膜脂会因受热而变得不饱和程度降低，但最近还观察到了其他变化，包括半乳糖脂的多聚半乳糖基化、半乳糖脂的头部基团酰化、磷脂酸和三酰甘油的增加以及甾醇糖苷和酰基甾醇糖苷的形成。在这项工作中，我们通过质谱法测量脂质水平，证实了之前在三种热应激方案下观察到的叶片脂质变化。此外，研究表明，受热时，叶片半乳糖脂、磺基喹喔啉二酰基甘油和磷脂酰甘油的脂肪酰链氧化增加，且氧化的酰基链会掺入酰化单半乳糖基二酰基甘油中。我们还观察到二半乳糖基单酰基甘油和单半乳糖基单酰基甘油的水平有所增加。我们测试了甾醇糖基化缺陷会对经历严重热应激方案后的植物再生产生不利影响这一假设，但未检测到野生型植物和甾醇糖基化缺陷型植物之间存在差异。
