College of Environmental Science & Engineering, Guilin University of Technology, Guilin 541006, China; The Guangxi Key Laboratory of Theory and Technology for Environmental Pollution Control, Guilin University of Technology, Guilin 541006, China; Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin 541006, China.
College of Environmental Science & Engineering, Guilin University of Technology, Guilin 541006, China.
Ecotoxicol Environ Saf. 2024 Sep 1;282:116725. doi: 10.1016/j.ecoenv.2024.116725. Epub 2024 Jul 12.
The cell wall serves as the primary barrier against the entry of heavy metal ions into cells. However, excessive accumulation of heavy metals within plants can lead to alterations in the spatial structure and physical properties of the cell wall, thereby affecting the capacity of plants to capture heavy metals. Proline (Pro) is involved in the synthesis of the cell wall, modulating the stability and integrity of its structure. Extensins, core proteins that maintain the cell wall structure, are proline/hydroxyproline-rich glycoproteins that contain the characteristic sequence Ser-[Pro]. They act as intermediates in the regulation of biological processes such as cell wall synthesis, assembly, and signal transduction, typically forming a network structure of cell wall proteins through cross-linking with pectin. This network is essential for the self-assembly expansion of the plant cell wall and plays an indispensable role in cell wall stress signal transduction through its interaction with intracellular signalling molecules. However, the mechanisms by which Pro affects the synthesis of cell wall structural proteins, cell wall assembly, and the sensing of cell wall stress under heavy metal stress remain unclear. This review, from the perspectives of biochemistry and molecular biology, comprehensively elaborates on the impact of Pro and Pro-rich proteins on the structure and function of the cell wall. These findings emphasize the mechanism by which Pro enhances the ability of the cell wall to capture heavy metals, providing new research ideas for the use of genetic engineering to manipulate cell wall synthesis and repair, thereby reducing the phytotoxicity of heavy metals.
细胞壁作为主要的屏障，防止重金属离子进入细胞。然而，植物内重金属的过度积累会导致细胞壁空间结构和物理性质的改变，从而影响植物捕获重金属的能力。脯氨酸（Pro）参与细胞壁的合成，调节其结构的稳定性和完整性。伸展蛋白是维持细胞壁结构的核心蛋白，是脯氨酸/羟脯氨酸丰富的糖蛋白，含有特征序列 Ser-[Pro]。它们作为细胞壁合成、组装和信号转导等生物过程调节的中介物，通常通过与果胶的交联形成细胞壁蛋白的网络结构。这个网络对于植物细胞壁的自组装扩张至关重要，并且通过与细胞内信号分子的相互作用，在细胞壁应激信号转导中发挥不可或缺的作用。然而，Pro 影响细胞壁结构蛋白合成、细胞壁组装以及重金属胁迫下细胞壁应激感知的机制仍不清楚。本综述从生物化学和分子生物学的角度，全面阐述了 Pro 和 Pro 丰富蛋白对细胞壁结构和功能的影响。这些发现强调了 Pro 增强细胞壁捕获重金属能力的机制，为利用基因工程操纵细胞壁合成和修复提供了新的研究思路，从而降低重金属的植物毒性。
