State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, Shandong, PR China.
Plant Physiol Biochem. 2012 Sep;58:174-81. doi: 10.1016/j.plaphy.2012.06.020. Epub 2012 Jul 5.
Mitogen-activated protein kinase (MAPK) cascades play important roles in mediating biotic and abiotic stress responses. In this study, we found that ZmMPK4 protein was predominantly localized in the nucleus. Semi-quantitative RT-PCR analysis revealed that the ZmMPK4 transcription in maize leaves was up-regulated by low temperature, high temperature and exogenous signaling molecules such as hydrogen peroxide, methyl jasmonate and ethephon. Hydrogen peroxide acted as second messenger to mediate 4°C-induced up-regulation of ZmMPK4 mRNA. Transgenic tobacco of overexpressing ZmMPK4 accumulated less reactive oxygen species (ROS), more peroxidase and catalase activities, more proline and soluble sugar contents, and more stress-responsive genes expression, leading to enhancing low temperature stress tolerance compared to the control plants. Taken together, these results strongly suggest that ZmMPK4 positively regulates low temperature stress tolerance in plants.
丝裂原活化蛋白激酶（MAPK）级联在介导生物和非生物胁迫反应中发挥重要作用。在这项研究中，我们发现 ZmMPK4 蛋白主要定位于细胞核。半定量 RT-PCR 分析表明，玉米叶片中的 ZmMPK4 转录受低温、高温和外源信号分子如过氧化氢、茉莉酸甲酯和乙烯利的上调。过氧化氢作为第二信使介导 4°C 诱导的 ZmMPK4 mRNA 的上调。过表达 ZmMPK4 的转基因烟草积累较少的活性氧（ROS），过氧化物酶和过氧化氢酶活性更高，脯氨酸和可溶性糖含量更高，应激响应基因表达更多，与对照植物相比，增强了低温胁迫耐受性。总之，这些结果强烈表明 ZmMPK4 正向调节植物的低温胁迫耐受性。
