The Franciszek Górski Institute of Plant Physiology of the Polish Academy of Sciences, ul. Niezapominajek 21, 30-239 Kraków, Poland.
Faculty of Biochemistry, Biophysics and Biotechnology of the Jagiellonian University, ul. Gronostajowa 7, 30-387 Kraków, Poland.
Int J Mol Sci. 2021 Oct 21;22(21):11370. doi: 10.3390/ijms222111370.
To determine the role of α- and γ-tocopherol (TC), this study compared the response to salt stress (200 mM NaCl) in wild type (WT) (L.) Heynh. And its two mutants: (1) totally TC-deficient ; (2) accumulating γ-TC instead of α-TC; and (3) transgenic line overaccumulating α-TC. Raman spectra revealed that salt-exposed α-TC accumulating plants were more flexible in regulating chlorophyll, carotenoid and polysaccharide levels than TC deficient mutants, while the plants overaccumulating γ-TC had the lowest levels of these biocompounds. Tocopherol composition and NaCl concentration affected xanthophyll cycle by changing the rate of violaxanthin de-epoxidation and zeaxanthin formation. NaCl treated plants with altered TC composition accumulated less oligosaccharides than WT plants. α-TC deficient plants increased their oligosaccharide levels and reduced maltose amount, while excessive accumulation of α-TC corresponded with enhanced amounts of maltose. Salt-stressed TC-deficient mutants and transgenic line exhibited greater proline levels than WT plants, lower chlorogenic acid levels, and lower activity of catalase and peroxidases. α-TC accumulating plants produced more methylated proline- and glycine- betaines, and showed greater activity of superoxide dismutase than γ-TC deficient plants. Under salt stress, α-TC demonstrated a stronger regulatory effect on carbon- and nitrogen-related metabolites reorganization and modulation of antioxidant patterns than γ-TC. This suggested different links of α- and γ-TCs with various metabolic pathways via various functions and metabolic loops.
为了确定 α-和 γ-生育酚（TC）的作用，本研究比较了野生型（WT）（L.）Heynh 及其两个突变体：（1）完全缺乏 TC；（2）积累 γ-TC 而不是 α-TC；和（3）过度积累 α-TC 的转基因系对盐胁迫（200 mM NaCl）的反应。拉曼光谱表明，暴露于盐的积累 α-TC 的植物在调节叶绿素、类胡萝卜素和多糖水平方面比缺乏 TC 的突变体更具灵活性，而过度积累 γ-TC 的植物则具有最低水平的这些生物化合物。生育酚组成和 NaCl 浓度通过改变紫黄质脱环氧化和玉米黄质形成的速率来影响叶黄素循环。改变 TC 组成的 NaCl 处理植物比 WT 植物积累的低聚糖更少。缺乏 α-TC 的植物增加了它们的低聚糖水平并减少了麦芽糖的含量，而过量积累 α-TC 则对应着麦芽糖含量的增加。缺乏 TC 的盐胁迫突变体和转基因系表现出比 WT 植物更高的脯氨酸水平、更低的绿原酸水平、更低的过氧化氢酶和过氧化物酶活性。积累 α-TC 的植物产生了更多的甲基化脯氨酸和甘氨酸甜菜碱，并且超氧化物歧化酶的活性高于缺乏 γ-TC 的植物。在盐胁迫下，α-TC 对碳和氮相关代谢物重组的调节作用比 γ-TC 更强，并且调节抗氧化模式。这表明 α-和 γ-TC 通过各种功能和代谢循环与各种代谢途径具有不同的联系。
