State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong 271018, PR China.
J Plant Physiol. 2010 Oct 15;167(15):1307-15. doi: 10.1016/j.jplph.2010.04.014. Epub 2010 Jun 26.
Low temperature is one of the most common environmental stresses affecting plant growth and agricultural production. Serine/threonine protein phosphatases 2C (PP2Cs) have been suggested to play an important role in stress signaling. To identify potential new member of the PP2C proteins in maize and investigate its functions for stress responses, the ZmPP2C2 gene, encoding a new PP2C protein from maize roots, was cloned by RT-PCR and RACE-PCR. Its constitutive expression in roots, stems and leaves of maize seedlings was detected by RNA gel blot, and its regulation in response to cold stress was also examined. To further evaluate its function in the cold stress response, we over-expressed the ZmPP2C2 gene in tobacco under the control of the Cauliflower Mosaic Virus (CaMV) 35S promoter, and assessed a series of physiological changes in wild type and transgenic plants under low temperatures. Compared with wild type tobacco under cold stress, plants that over-expressed ZmPP2C2 displayed higher germination speed and rate, higher antioxidant enzyme (SOD, POD, CAT) activities, with lower cold-induced electrolyte leakage and malondialdehyde (MDA) contents. These results show that over-expression of ZmPP2C2 in tobacco enhanced tolerance to cold stress, suggesting that this new gene, ZmPP2C2, may act as a positive regulator of cold resistance in plants.
低温是影响植物生长和农业生产的最常见环境胁迫之一。丝氨酸/苏氨酸蛋白磷酸酶 2C（PP2Cs）被认为在胁迫信号转导中发挥重要作用。为了鉴定玉米中潜在的新的 PP2C 蛋白成员，并研究其在胁迫响应中的功能，通过 RT-PCR 和 RACE-PCR 克隆了编码玉米根中新的 PP2C 蛋白的 ZmPP2C2 基因。通过 RNA 凝胶印迹检测其在玉米幼苗根、茎和叶中的组成型表达，并研究其对冷胁迫的调节。为了进一步评估其在冷胁迫响应中的功能，我们在烟草中过表达了 ZmPP2C2 基因，受花椰菜花叶病毒（CaMV）35S 启动子的控制，并在低温下评估了野生型和转基因植物的一系列生理变化。与冷胁迫下的野生型烟草相比，过表达 ZmPP2C2 的植物表现出更高的发芽速度和发芽率，更高的抗氧化酶（SOD、POD、CAT）活性，更低的冷诱导电解质泄漏和丙二醛（MDA）含量。这些结果表明，烟草中过表达 ZmPP2C2 增强了对冷胁迫的耐受性，表明该新基因 ZmPP2C2 可能作为植物抗寒性的正调控因子。
