Xu Ziyue, Liu Dun, Zhu Jiadong, Zhao Jiayi, Shen Shenghai, Wang Yueduo, Yu Pei
SDU-ANU Joint Science College, Shandong University, Weihai, 264209, China.
Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR, China.
Planta. 2024 Dec 17;261(1):16. doi: 10.1007/s00425-024-04594-w.
This review highlights the sulfur transporters, key enzymes and their encoding genes involved in plant sulfur anabolism, focusing on their occurrence, chemistry, location, function, and regulation within sulfur assimilation pathways. Sulfur, a vital element for plant life, plays diverse roles in metabolism and stress response. This review provides a comprehensive overview of the sulfur assimilation pathway in plants, highlighting the intricate network of enzymes and their regulatory mechanisms. The primary focus is on the key enzymes involved: ATP sulfurylase (ATPS), APS reductase (APR), sulfite reductase (SiR), serine acetyltransferase (SAT), and O-acetylserine(thiol)lyase (OAS-TL). ATPS initiates the process by activating sulfate to form APS, which is then reduced to sulfite by APR. SiR further reduces sulfite to sulfide, a crucial step that requires significant energy. The cysteine synthase complex (CSC), formed by SAT and OAS-TL, facilitates the synthesis of cysteine, thereby integrating serine metabolism with sulfur assimilation. The alternative sulfation pathway, catalyzed by APS kinase and sulfotransferases, is explored for its role in synthesizing essential secondary metabolites. This review also delves into the regulatory mechanism of these enzymes such as environmental stresses, sulfate availability, phytohormones, as well as translational and post-translational regulations. Understanding the key transporters and enzymes in sulfur assimilation pathways and their corresponding regulation mechanisms can help researchers grasp the importance of sulfur anabolism for the life cycle of plants, clarify how these enzymes and their regulatory processes are integrated to balance plant life systems in response to changes in both external conditions and intrinsic signals.
本综述重点介绍了参与植物硫同化作用的硫转运蛋白、关键酶及其编码基因，着重阐述了它们在硫同化途径中的存在形式、化学性质、位置、功能及调控。硫是植物生命必需的元素，在新陈代谢和应激反应中发挥着多种作用。本综述全面概述了植物硫同化途径，突出了酶的复杂网络及其调控机制。主要关注的关键酶有：ATP硫酸化酶（ATPS）、APS还原酶（APR）、亚硫酸盐还原酶（SiR）、丝氨酸乙酰转移酶（SAT）和O-乙酰丝氨酸（硫醇）裂解酶（OAS-TL）。ATPS通过激活硫酸盐形成APS启动这一过程，随后APS被APR还原为亚硫酸盐。SiR进一步将亚硫酸盐还原为硫化物，这是一个需要大量能量的关键步骤。由SAT和OAS-TL组成的半胱氨酸合成酶复合体（CSC）促进半胱氨酸的合成，从而将丝氨酸代谢与硫同化整合起来。还探讨了由APS激酶和磺基转移酶催化的替代硫酸化途径在合成必需次生代谢产物中的作用。本综述还深入研究了这些酶的调控机制，如环境胁迫、硫酸盐可用性、植物激素，以及翻译和翻译后调控。了解硫同化途径中的关键转运蛋白和酶及其相应的调控机制，有助于研究人员认识硫同化作用对植物生命周期的重要性，阐明这些酶及其调控过程如何整合以响应外部条件和内在信号的变化来平衡植物生命系统。
