Lin C, Chen S
a Department of Biology , University of Florida , Gainesville , FL , USA.
b University of Florida Genetics Institute (UFGI) , Gainesville , FL , USA.
Plant Signal Behav. 2018;13(5):e1477908. doi: 10.1080/15592324.2018.1477908. Epub 2018 Jun 26.
Mitogen-activated protein kinase (MPK) cascades play important roles in plant development, immune signaling and stress responses. MPK4 was initially identified as a negative regulator in systemic acquired resistance (SAR) because the levels of salicylic acid (SA) and reactive oxygen species (ROS) were higher in the Arabidopsis mpk4 mutant. MPK4 is highly expressed in guard cells, specialized epidermal cells forming stomatal pores on leaf surface that function at the frontline of bacterial pathogen invasion. In addition to biotic stresses, stomatal guard cells also mediate cellular responses to abiotic stimuli such as drought and CO changes. MPK4 appears to play different roles in different plant systems. In this review, we briefly discuss the protein kinase MPK4 functions and focus on its signaling roles in different plant systems, especially in stomatal guard cells.
丝裂原活化蛋白激酶（MPK）级联反应在植物发育、免疫信号传导和应激反应中发挥着重要作用。MPK4最初被鉴定为系统获得性抗性（SAR）的负调控因子，因为拟南芥mpk4突变体中水杨酸（SA）和活性氧（ROS）的水平较高。MPK4在保卫细胞中高度表达，保卫细胞是在叶表面形成气孔孔的特化表皮细胞，在细菌病原体入侵的前沿发挥作用。除了生物胁迫外，气孔保卫细胞还介导细胞对干旱和CO变化等非生物刺激的反应。MPK4似乎在不同的植物系统中发挥不同的作用。在这篇综述中，我们简要讨论了蛋白激酶MPK4的功能，并重点关注其在不同植物系统中的信号传导作用，特别是在气孔保卫细胞中的作用。
