Anxi College of Tea Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Department of Cosmetic Science, Chia Nan University of Pharmacy and Science, No. 60, Section 1, Erren Rd. Rende Dist., Tainan City 71710, Taiwan.
Int J Mol Sci. 2019 Jun 24;20(12):3082. doi: 10.3390/ijms20123082.
We have analyzed protein expression in the bleached small vegetative cells of synchronous to investigate how unicellular algae lived through stress. These cells were subjected to heat treatment (46.5 °C for 1h in dark condition) and then cultured under continuous illumination for 24 h. Flow cytometry analysis of the chlorophyll autofluorescence intensity of cells indicated that heat-treated cells were completely bleached within 24 h of light cultivation. Transmission electron microscopy (TEM) images showed that bleached cells maintained thylakoid membrane structure, but with lower contrast. The bleached cells regained green color after 72 h, along with a recovery in contrast, which indicated a return of photosynthetic ability. Two-dimensional gel electrophoresis (2DE) showed that the protein expression patterns were very difference between control and bleached cells. ATP synthase subunits and glutamine synthetase were down-regulated among the many differences, while some of phototransduction, stress response proteins were up-regulated in bleached cells, elucidating bleached cells can undergo changes in their biochemical activity, and activate some stress response proteins to survive the heat stress and then revive. In addition, small heat shock proteins (HSPs), but not HSP40 and HSP70 family proteins, protected the bleaching cells.
我们分析了同步培养的白化小营养细胞中的蛋白质表达，以研究单细胞藻类如何在应激下生存。这些细胞先经受热处理（黑暗条件下 46.5°C 处理 1 小时），然后在持续光照下培养 24 小时。细胞叶绿素自发荧光强度的流式细胞术分析表明，热处理细胞在光照培养的 24 小时内完全白化。透射电子显微镜（TEM）图像显示，白化细胞保持类囊体膜结构，但对比度较低。白化细胞在 72 小时后恢复绿色，对比度恢复，表明光合作用能力恢复。二维凝胶电泳（2DE）显示，对照和白化细胞之间的蛋白质表达模式差异非常大。ATP 合酶亚基和谷氨酰胺合成酶下调，而一些光转导、应激响应蛋白在白化细胞中上调，阐明白化细胞可以在其生化活性上发生变化，并激活一些应激响应蛋白以在热应激后存活并恢复。此外，小热休克蛋白（HSPs），而不是 HSP40 和 HSP70 家族蛋白，保护白化细胞。
