Properties of cellular ubiquinone and stress-resistance in suspension-cultured cells of Chorispora bungeana during early chilling

Redox regulation of cellular components under stress is active and, in the present study, we found that in suspension-cultured cells of Chorispora bungeana Fisch. & C.A. Mey., a rare alpine subnival plant surviving in cold regions, the rebalance of redox state of cellular ubiquinone is very active in early chilling stress. We examined the mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) production by using flow cytometry and the level of reductive ubiquinone through HPLC in suspension-cultured cells of C. bungeana, so as to investigate the cellular activity under different low temperature. It was found that compared with 25 °C, the level of reductive ubiquinone kept decreasing under different chilling temperature. Meanwhile, chilling induction cannot impair cell activity since MMP kept stabilizing under early chilling and the accumulation of ROS production did not fluctuate at the same time. These findings suggested that the special mechanism of chilling-resistance in the alpine subnival plant is tightly linked with redox balance of its cellular redox molecule and, in early chilling, the redox transition of ubiquinone cannot only ensure the fluency of electron transfer in mitochondria but also facilitate the regulation of the whole-cell redox states leading to adaptation of cellular regulations.