Beris Despoina, Ioanna Malandraki, Vassilakos Nikon, Theologidis Ioannis, Rampou Aggeliki, Kektsidou Oxana, Massart Sebastien, Varveri Christina
Laboratory of Virology, Scientific Directorate of Phytopathology, Benaki Phytopathological Institute, Athens 14561, Greece.
Laboratory of Plant Pathology, TERRA, Gembloux Agro-Bio Tech, University of Liège, Gembloux 5030, Belgium.
Phytopathology. 2021 Oct;111(10):1782-1789. doi: 10.1094/PHYTO-01-21-0027-R. Epub 2021 Nov 3.
Citrus impietratura disease (CID) is a graft transmissible, virus-like disease observed in old-line citrus trees; its characteristic symptom is the appearance of gum in the albedo of the affected fruits. To identify the causal agent of the disease, high-throughput sequencing (HTS) was performed on symptomatic orange fruits. The analysis of the obtained data revealed in all samples mixed infections of viroids commonly found in citrus trees together with the recently described citrus virus A (CiVA). Examination of additional symptomatic fruits with conventional reverse transcription PCR led to the identification of a single CiVA infection in one tree, which was verified by HTS. Indexing of the single CiVA-infected tree on indicator plants resulted in the appearance of characteristic symptoms in the leaves that were correlated with virus accumulation. Moreover, a comparative analysis among symptomatic and asymptomatic fruits derived from the same trees was performed and included the single CiVA-infected orange tree. The analysis revealed a positive correlation between the appearance of symptoms and the accumulation of CiVA RNAs. To facilitate CiVA detection during certification programs of propagation material, a quantitative RT-PCR targeting the movement protein of the virus was developed and evaluated for reliable and sensitive detection of the virus. To the best of our knowledge this is the first study that associates CiVA with the appearance of CID symptoms.
柑橘黑斑病（CID）是一种在老品种柑橘树上观察到的可嫁接传播的类病毒病；其特征症状是受影响果实的白皮层出现树胶。为了确定该病的病原体，对有症状的橙子果实进行了高通量测序（HTS）。对所得数据的分析表明，在所有样本中，柑橘树上常见的类病毒与最近描述的柑橘病毒A（CiVA）混合感染。用传统逆转录PCR对其他有症状的果实进行检测，在一棵树中鉴定出单一的CiVA感染，这通过HTS得到了验证。在指示植物上对单一CiVA感染的树进行索引，导致叶片出现与病毒积累相关的特征症状。此外，对来自同一棵树的有症状和无症状果实进行了比较分析，包括单一CiVA感染的橙子树。分析表明症状的出现与CiVA RNA的积累之间存在正相关。为了便于在繁殖材料认证程序中检测CiVA，开发了一种靶向该病毒运动蛋白的定量RT-PCR，并对其进行评估以实现对该病毒的可靠和灵敏检测。据我们所知，这是第一项将CiVA与CID症状出现相关联的研究。
