Table3.XLSX

Citral exhibits strong antifungal activity against Penicillium digitatum. In this study, 41 over-expressed and 84 repressed proteins in P. digitatum after 1.0 μL/mL of citral exposure for 30 min were identified by the iTRAQ technique. The proteins were closely related with oxidative phosphorylation, the TCA cycle and RNA transport. The mitochondrial complex I, complex II, complex III, complex IV and complex V, which are involved in oxidative phosphorylation were drastically affected. Among of them, the activities of mitochondrial complex I and complex IV were apparently suppressed, whereas those of mitochondrial complex II, complex III and complex V were significantly induced. Meanwhile, citral apparently triggered a reduction in the intracellular ATP, the mitochondrial membrane potential (MMP) and glutathione content, in contrast to an increase in the glutathione S-transferase activity and the accumulation of reactive oxygen species (ROS). Addition of exogenous cysteine decreased the antifungal activity. In addition, cysteine maintained the basal ROS level, deferred the decrease of MMP and the membrane damage. These results indicate that citral inhibited the growth of P. digitatum by damaging oxidative phosphorylation and cell membranes through the massive accumulation of ROS.

柠檬醛（Citral）对指状青霉（Penicillium digitatum）具有强效抗真菌活性。本研究采用iTRAQ（同位素标记相对和绝对定量）技术，鉴定出经1.0 μL/mL柠檬醛处理30分钟后，指状青霉体内41种上调表达蛋白与84种下调表达蛋白。上述差异蛋白与氧化磷酸化、三羧酸循环（TCA cycle）及RNA转运密切相关。参与氧化磷酸化过程的线粒体复合物I、复合物II、复合物III、复合物IV及复合物V均受到显著影响。其中，线粒体复合物I与复合物IV的活性受到明显抑制，而复合物II、III及V的活性则显著上调。与此同时，柠檬醛可显著降低细胞内ATP水平、线粒体膜电位（MMP）及谷胱甘肽含量，同时提升谷胱甘肽S-转移酶（glutathione S-transferase）活性并促使活性氧（ROS）大量积累。外源添加半胱氨酸可削弱柠檬醛的抗真菌活性；此外，半胱氨酸能够维持细胞基础活性氧水平，延缓线粒体膜电位下降与细胞膜损伤进程。上述结果表明，柠檬醛通过诱导活性氧大量积累，破坏氧化磷酸化过程与细胞膜结构，进而抑制指状青霉的生长。