College of Life Sciences, China Jiliang University, 258 Xueyuan Street, Hangzhou, Zhejiang 310018, China.
Purdue Center for Plant Biology, Department of Botany and Plant Pathology, Purdue University, 915 W. State Street, West Lafayette, IN 47907-2054, USA.
Int J Mol Sci. 2021 Feb 27;22(5):2393. doi: 10.3390/ijms22052393.
Plants are constantly exposed to a wide range of potential pathogens and to protect themselves, have developed a variety of chemical and physical defense mechanisms. Callose is a β-(1,3)-D-glucan that is widely distributed in higher plants. In addition to its role in normal growth and development, callose plays an important role in plant defense. Callose is deposited between the plasma membrane and the cell wall at the site of pathogen attack, at the plasmodesmata, and on other plant tissues to slow pathogen invasion and spread. Since it was first reported more than a century ago, defense-related callose deposition has been extensively studied in a wide-spectrum of plant-pathogen systems. Over the past 20 years or so, a large number of studies have been published that address the dynamic nature of pathogen-induced callose deposition, the complex regulation of synthesis and transport of defense-related callose and associated callose synthases, and its important roles in plant defense responses. In this review, we summarize our current understanding of the regulation and function of defense-related callose deposition in plants and discuss both the progresses and future challenges in addressing this complex defense mechanism as a critical component of a plant immune system.
植物经常暴露于各种潜在的病原体中，为了保护自己，它们已经发展出了多种化学和物理防御机制。几丁质是一种广泛存在于高等植物中的β-(1,3)-D-葡聚糖。除了在正常生长和发育中的作用外，几丁质在植物防御中也起着重要作用。在病原体攻击的部位、在胞间连丝以及在其他植物组织中，几丁质沉积在质膜和细胞壁之间，以减缓病原体的入侵和传播。自从一个多世纪前首次报道以来，在广泛的植物-病原体系统中，与防御相关的几丁质沉积已经被广泛研究。在过去的 20 年左右的时间里，已经发表了大量的研究，这些研究涉及到病原体诱导的几丁质沉积的动态性质、与防御相关的几丁质的合成和运输的复杂调节以及与其相关的几丁质合成酶，以及它在植物防御反应中的重要作用。在这篇综述中，我们总结了我们目前对植物中与防御相关的几丁质沉积的调节和功能的理解，并讨论了作为植物免疫系统关键组成部分的这一复杂防御机制的进展和未来挑战。
