College of Life Sciences, Nankai University, Tianjin 300071, China.
Plant Physiol Biochem. 2012 Feb;51:175-84. doi: 10.1016/j.plaphy.2011.11.003. Epub 2011 Nov 11.
Acetic acid widely spreads in atmosphere, aquatic ecosystems containing residues and anoxic soil. It can inhibit aquatic plant germination and growth, and even cause programmed cell death (PCD) of yeast. In the present study, biochemical and physiological responses of the model unicellular green algae Chlamydomonas reinhardtii were examined after acetic acid stress. H(2)O(2) burst was found in C. reinhardtii after acetic acid stress at pH 5.0 for 10 min. The photosynthetic pigments were degraded, gross photosynthesis and respiration were disappeared gradually, and DNA fragmentation was also detected. Those results indicated that C. reinhardtii cells underwent a PCD but not a necrotic, accidental cell death event. It was noticed that C. reinhardtii cells in PCD released abundant volatile organic compounds (VOCs) upon acetic acid stress. Therefore, we analyzed the VOCs and tested their effects on other normal cells. The treatment of C. reinhardtii cultures with VOCs reduced the cell density and increased antioxidant enzyme activity. Therefore, a function of VOCs as infochemicals involved in cell-to-cell communication at the conditions of applied stress is suggested.
乙酸广泛存在于大气、含有残留物的水生生态系统和缺氧土壤中。它可以抑制水生植物的发芽和生长，甚至导致酵母的程序性细胞死亡（PCD）。在本研究中，研究了模式单细胞绿藻莱茵衣藻在乙酸胁迫后的生化和生理反应。在 pH 值为 5.0 的乙酸胁迫 10 分钟后，发现莱茵衣藻中出现了 H₂O₂爆发。光合色素降解，总光合作用和呼吸作用逐渐消失，并且还检测到 DNA 片段化。这些结果表明莱茵衣藻细胞经历了 PCD，但不是坏死或意外的细胞死亡事件。值得注意的是，在 PCD 过程中，莱茵衣藻细胞在受到乙酸胁迫时会释放出大量的挥发性有机化合物（VOCs）。因此，我们分析了这些 VOCs 并测试了它们对其他正常细胞的影响。用 VOCs 处理莱茵衣藻培养物会降低细胞密度并增加抗氧化酶活性。因此，建议 VOCs 作为信息素在施加应激条件下参与细胞间通讯的功能。
