Abstract：
To understand the role of reactive oxygen species (ROS) in regulation of the plasma membrane (PM) H+-ATPase in acid-stressed Masson pine roots, different acidity (pH 6.6 as the control, pH 5.6 and pH 4.6) of simulated acid rain (SAR) added with and without external chemicals (H2O2, enzyme inhibitors and ROS scavenger) was prepared. After 30 days of SAR exposure, the plant morphological phenotype attributes, levels of cellular ROS and lipid peroxidation, enzymatic activities of antioxidants, PM nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and PM H+-ATPase activity in pine seedlings were measured. Compared with the control, the growth of pine seedlings exposed to SAR in the presence or absence of H2O2 was well-maintained, but the application of Na3VO4, 1,3-dimethyl-2-thiourea, N, N-dimethylthiourea (DMTU) and diphenyleneiodonium chloride (DPI) caused a substantial growth inhibition. In addition, SAR exposure, SAR with H2O2 treatment, and SAR with Na3VO4 treatment increased the cellular H2O2 content, O2- content and malondialdehyde (MDA) content, while the use of DMTU and DPI lead to relatively low levels. Similarly, the enzymatic activities of antioxidants, PM NADPH oxidase and PM H+-ATPase in acid stressed pine seedlings elevated with the increasing acidity. A significant stimulation of these enzymatic activities obtained from SAR with H2O2 treatment was observed, whereas which decreased obviously with the addition of Na3VO4, DMTU and DPI (P < 0.05). Moreover, a positive correlation was found between plant morphological attributes and the PM H+-ATPase activity (P < 0.05). Besides, the PM H+-ATPase activity positively correlated with the cellular ROS contents and the enzymatic activities of antioxidants and PM NADPH oxidase (P < 0.05). Therefore, the PM H+-ATPase is instrumental in the growth of pine seedlings resisting to acid stress by enhancing its activity. The process involves the signaling transduction of cellular ROS and coordination with PM NADPH oxidase.
摘要：
为了了解活性氧（ROS）在酸胁迫的马尾松根中对质膜（PM）H-ATPase的调节中的作用，不同的酸度(pH6.6作为对照，pH5.6，和pH4.6）的模拟酸雨（SAR）添加和不添加外部化学物质[H2O2，酶抑制剂，并准备了ROS清除剂]。SAR暴露30天后，植物形态表型属性，细胞ROS和脂质过氧化的水平，抗氧化剂的酶活性，烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶活性,并测定了松树幼苗中的PMH-ATPase活性。与对照相比，在存在或不存在H2O2的情况下，暴露于SAR的松树幼苗的生长得到了良好的维持，但Na3VO4,1,3-二甲基-2-硫脲的应用,N,N-二甲基硫脲(DMTU),和氯化二苯基碘鎓（DPI）引起了实质性的生长抑制。此外,SAR暴露,SAR与H2O2处理，和SAR与Na3VO4处理增加细胞H2O2含量，O2·-含量，丙二醛(MDA)含量,而使用DMTU和DPI导致相对较低的水平。同样，抗氧化剂的酶活性，PMNADPH氧化酶，酸胁迫松树幼苗中的PMH-ATPase随着酸度的增加而升高。观察到用H2O2处理从SAR获得的这些酶活性的显著刺激，而随着Na3VO4、DMTU的加入，DPI(P<0.05)。此外，植物形态属性与PMH+-ATPase活性呈正相关(P<0.05)。此外,PMH-ATPase活性与细胞ROS含量，抗氧化剂和PMNADPH氧化酶的酶活性呈正相关（P<0.05）。因此,PMH-ATPase通过增强其活性来促进抗酸胁迫的松树幼苗的生长。该过程涉及细胞ROS的信号转导和与PMNADPH氧化酶的协调。
