Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA.
Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, FL 32611, USA.
Int J Mol Sci. 2022 Jul 29;23(15):8375. doi: 10.3390/ijms23158375.
Viruses are trailblazers in hijacking host systems for their own needs. Plant viruses have been shown to exploit alternative avenues of translocation within a host, including a challenging route through the xylem, to expand their niche and establish systemic spread, despite apparent host-imposed obstacles. Recent findings indicate that plant viruses from many families could successfully hack xylem cells in a broad range of plant hosts, including herbaceous and perennial woody plants. Similar to virus-related structures present in the phloem, virus particles and membrane-containing viral replication complexes are often observed in the xylem. Except for a few single-stranded DNA viruses in the family and a negative-sense single-stranded RNA rhabdovirus, , the majority of the viruses that were detected in the xylem belong to the group of positive-sense RNA viruses. The diversity of the genome organization and virion morphology of those viruses indicates that xylem exploitation appears to be a widely adapted strategy for plant viruses. This review outlines the examples of the xylem-associated viruses and discusses factors that regulate virus inhabitation of the xylem as well as possible strategies of virus introduction into the xylem. In some cases, plant disease symptoms have been shown to be closely related to virus colonization of the xylem. Inhibiting viral xylem invasion could raise potential attractive approaches to manage virus diseases. Therefore, the identification of the host genes mediating virus interaction with the plant xylem tissue and understanding the underlying mechanisms call for more attention.
病毒是为了自身需求而劫持宿主系统的先驱。已证实植物病毒会利用宿主内的替代易位途径，包括通过木质部的挑战性途径，来扩大其生态位并建立系统传播，尽管存在明显的宿主施加的障碍。最近的发现表明，许多科的植物病毒可以成功地在广泛的植物宿主中劫持木质部细胞，包括草本和多年生木本植物。与韧皮部中存在的与病毒相关的结构类似，病毒粒子和含膜的病毒复制复合物经常在木质部中观察到。除了家族中的少数单链 DNA 病毒和负义单链 RNA 弹状病毒外，大多数在木质部中检测到的病毒属于正链 RNA 病毒组。这些病毒的基因组组织和病毒粒子形态的多样性表明，木质部的利用似乎是植物病毒广泛适应的策略。本综述概述了与木质部相关的病毒的例子，并讨论了调节病毒在木质部中栖息的因素以及病毒进入木质部的可能策略。在某些情况下，植物疾病症状与病毒在木质部的定殖密切相关。抑制病毒木质部入侵可能会提高管理病毒病的潜在有吸引力的方法。因此，鉴定介导病毒与植物木质部组织相互作用的宿主基因并理解潜在的机制需要更多的关注。
