Huanglongbing (HLB), formerly known as citrus greening disease, is one of the most devastating bacterial diseases in citrus worldwide. HLB is caused by ‘Candidatus Liberibacter asiaticus’ bacterium and transmitted by Diaphorina citri. Both ‘Ca. L. asiaticus’ and its vector manipulate the host metabolism to fulfill their nutritional needs and/or to neutralize the host defense responses. Herein, we discuss the history of HLB and the complexity of its pathosystem as well as the geographical distribution of its pathogens and vectors. Recently, our recognition of physiological events associated with ‘Ca. L. asiaticus’ infection and/or D. citri-infestation has greatly improved. However, the roles of citrus metabolites in the development of HLB symptoms are still unclear. We believe that symptom development of HLB disease is a complicated process and relies on a multilayered metabolic network which is mainly regulated by phytohormones. Citrus metabolites play vital roles in the development of HLB symptoms through the modulation of carbohydrate metabolism, phytohormone homeostasis, antioxidant pathways, or via the interaction with other metabolic pathways, particularly involving amino acids, leaf pigments, and polyamines. Understanding how ‘Ca. L. asiaticus’ and its vector, D. citri, affect the metabolic pathways of their host is critical for developing novel, sustainable strategies for HLB management.

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重新审视黄龙病的复杂病理系统：破译柑橘代谢物在症状发展中的作用

黄龙病（HLB），以前称为柑橘绿化病，是世界范围内柑橘最具破坏性的细菌性疾病之一。HLB 是由“ Candidatus Liberibacter asiaticus”细菌引起并由柑橘木虱传播。两者都' Ca。亚洲乳杆菌及其载体操纵宿主新陈代谢以满足其营养需求和/或中和宿主防御反应。在此，我们讨论 HLB 的历史及其病理系统的复杂性以及病原体和媒介的地理分布。最近，我们认识到与Ca相关的生理事件。L. asiaticus 感染和/或D. citri感染已大大改善。然而，柑橘代谢物在 HLB 症状发展中的作用仍不清楚。我们认为HLB疾病的症状发展是一个复杂的过程，依赖于主要受植物激素调节的多层代谢网络。柑橘代谢物通过调节碳水化合物代谢、植物激素稳态、抗氧化途径或通过与其他代谢途径（特别是涉及氨基酸、叶色素和多胺）的相互作用，在 HLB 症状的发展中发挥重要作用。了解如何' Ca。L. asiaticus 及其载体D. citri影响宿主的代谢途径，这对于制定新的、可持续的 HLB 管理策略至关重要。