In plants, cell-shape is defined by the cell wall, a complex network of polymers located outside the plasma membrane. During cell growth, cell wall properties have to be adjusted, assuring cell expansion without compromising cell integrity. Plasma membrane-located receptors sense cell wall properties, transducing extracellular signals into intracellular cascades through the cell wall integrity (CWI) pathway that, in turn, leads to adjustments in the regulation and composition of the cell wall. Using pollen tube growth as a single celled model system, we describe the importance of RAPID ALKALINIZATION FACTOR (RALF) peptides as sensors of cell wall integrity. RALF peptides can mediate the communication between cell wall components and plasma membrane-localized receptor-like kinases (RLKs) of the CrRLK1L family. The subsequent activation of intracellular pathways regulates H+, Ca2+, and ROS levels in the cell and apoplast, thereby modulating cell wall integrity. Interestingly, the RALF-CrRLK1L module and some of the components working up- and downstream of the RLK is conserved in many other developmental and physiological signaling processes.

中文翻译：

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要保存还是要破坏，这是一个问题：细胞壁完整性途径在花粉管生长中的作用。

在植物中，细胞的形状由细胞壁决定，细胞壁是位于质膜外部的复杂的聚合物网络。在细胞生长过程中，必须调整细胞壁特性，以确保细胞扩增而不损害细胞完整性。质膜定位的受体感知细胞壁特性，通过细胞壁完整性（CWI）途径将细胞外信号转导至细胞内级联反应，进而导致细胞壁调节和组成的调节。使用花粉管生长作为单细胞模型系统，我们描述了快速碱化因子（RALF）肽作为细胞壁完整性传感器的重要性。RALF肽可以介导细胞壁成分与CrRLK1L家族的质膜定位受体样激酶（RLK）之间的通讯。细胞内通路的后续激活调节细胞和质外体中的H +，Ca2 +和ROS水平，从而调节细胞壁完整性。有趣的是，在许多其他发育和生理信号转导过程中，RALF-CrRLK1L模块和在RLK上下游起作用的某些组件得到了保护。