Chen Jingsheng, Xu Xiaofeng, Liu Wei, Feng Ziyang, Chen Quan, Zhou You, Sun Miao, Gan Liping, Zhou Tiange, Xuan Yuanhu
College of Biology and Food Engineering, Chongqing Three Gorges University, Chongqing 404100, China.
College of Plant Protection, Northeast Agricultural University, Harbin 150030, China.
Plants (Basel). 2024 Aug 13;13(16):2242. doi: 10.3390/plants13162242.
Callose, found in the cell walls of higher plants such as β-1,3-glucan with β-1,6 branches, is pivotal for both plant development and responses to biotic and abiotic stressors. Plasmodesmata (PD), membranous channels linking the cytoplasm, plasma membrane, and endoplasmic reticulum of adjacent cells, facilitate molecular transport, crucial for developmental and physiological processes. The regulation of both the structural and transport functions of PD is intricate. The accumulation of callose in the PD neck is particularly significant for the regulation of PD permeability. This callose deposition, occurring at a specific site of pathogenic incursion, decelerates the invasion and proliferation of pathogens by reducing the PD pore size. Scholarly investigations over the past two decades have illuminated pathogen-induced callose deposition and the ensuing PD regulation. This gradual understanding reveals the complex regulatory interactions governing defense-related callose accumulation and protein-mediated PD regulation, underscoring its role in plant defense. This review systematically outlines callose accumulation mechanisms and enzymatic regulation in plant defense and discusses PD's varied participation against viral, fungal, and bacterial infestations. It scrutinizes callose-induced structural changes in PD, highlighting their implications for plant immunity. This review emphasizes dynamic callose calibration in PD constrictions and elucidates the implications and potential challenges of this intricate defense mechanism, integral to the plant's immune system.
胼胝质存在于高等植物的细胞壁中，是一种具有β-1,6分支的β-1,3-葡聚糖，对植物发育以及对生物和非生物胁迫的反应都至关重要。胞间连丝（PD）是连接相邻细胞的细胞质、质膜和内质网的膜性通道，有助于分子运输，这对发育和生理过程至关重要。PD的结构和运输功能的调节很复杂。胼胝质在PD颈部的积累对于PD通透性的调节尤为重要。这种胼胝质沉积发生在病原体入侵的特定部位，通过减小PD孔径来减缓病原体的入侵和增殖。过去二十年的学术研究阐明了病原体诱导的胼胝质沉积以及随之而来的PD调节。这种逐渐深入的理解揭示了控制与防御相关的胼胝质积累和蛋白质介导的PD调节的复杂调控相互作用，突显了其在植物防御中的作用。本综述系统地概述了植物防御中胼胝质的积累机制和酶促调节，并讨论了PD在对抗病毒、真菌和细菌侵染中的不同参与情况。它仔细研究了胼胝质诱导的PD结构变化，强调了它们对植物免疫的影响。本综述强调了PD收缩中动态胼胝质校准，并阐明了这种复杂防御机制的影响和潜在挑战，这是植物免疫系统不可或缺的一部分。
