Candidatus Liberibacter asiaticus (CLas) is one the causative agents of greening disease in citrus, an unccurable, devastating disease of citrus worldwide. CLas is vectored by Diaphorina citri, and the understanding of the molecular interplay between vector and pathogen will provide additional basis for the development and implementation of successful management strategies. We focused in the molecular interplay occurring in the gut of the vector, a major barrier for CLas invasion and colonization. We investigated the differential expression of vector and CLas genes by analyzing a de novo reference metatranscriptome of the gut of adult psyllids fed of CLas-infected and healthy citrus plants for 1-2, 3-4 and 5-6 days. CLas regulates the immune response of the vector affecting the production of reactive species of oxygen and nitrogen, and the production of antimicrobial peptides. Moreover, CLas overexpressed peroxiredoxin, probably in a protective manner. The major transcript involved in immune expression was related to melanization, a CLIP-domain serine protease we believe participates in the wounding of epithelial cells damaged during infection, which is supported by the down-regulation of pangolin. We also detected that CLas modulates the gut peristalsis of psyllids through the down-regulation of titin, reducing the elimination of CLas with faeces. The up-regulation of the neuromodulator arylalkylamine N-acetyltransferase implies CLas also interferes with the double brain-gut communication circuitry of the vector. CLas colonizes the gut by expressing two Type IVb pilin flp genes and several chaperones that can also function as adhesins. We hypothesized biofilm formation occurs by the expression of the cold shock protein of CLas. The thorough detailed analysis of the transcritome of Ca. L. asiaticus and of D. citri at different time points of their interaction in the gut tissues of the host led to the identification of several host genes targeted for regulation by L. asiaticus, but also bacterial genes coding for potential effector proteins. The identified targets and effector proteins are potential targets for the development of new management strategies directed to interfere with the successful utilization of the psyllid vector by this pathogen.

中文翻译：

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感染建立的分子相互作用——柑橘皮甲虫和亚洲自由杆菌的基因表达

Candidatus Liberibacter asiaticus (CLas) 是柑橘绿化病的病原体之一，这是一种全世界范围内无法治愈的毁灭性柑橘病害。CLas 是由柑橘木虱传播的，对载体和病原体之间分子相互作用的了解将为制定和实施成功的管理策略提供额外的基础。我们重点研究载体肠道中发生的分子相互作用，这是 CLas 入侵和定植的主要障碍。我们通过分析用 CLas 感染和健康柑橘植物喂养 1-2、3-4 和 5-6 天的成年木虱肠道的从头参考元转录组，研究了载体和 CLas 基因的差异表达。CLas 调节载体的免疫反应，影响氧和氮活性物质的产生以及抗菌肽的产生。此外，CLas 过度表达过氧化还原蛋白，这可能是一种保护性方式。参与免疫表达的主要转录物与黑化有关，黑化是一种 CLIP 结构域丝氨酸蛋白酶，我们认为参与感染期间受损上皮细胞的损伤，穿山甲的下调支持了这一点。我们还检测到，CLAs 通过下调肌联蛋白来调节木虱的肠道蠕动，从而减少粪便中 CLAs 的消除。神经调节剂芳烷基胺 N-乙酰转移酶的上调意味着 CLas 也会干扰载体的双脑肠通讯回路。CLas 通过表达两个 IVb 型菌毛蛋白 flp 基因和几个也可充当粘附素的分子伴侣在肠道中定殖。我们假设生物膜的形成是通过 CLas 冷休克蛋白的表达而发生的。Ca 转录组的彻底详细分析。L. asiaticus 和 D. citri 在宿主肠道组织中相互作用的不同时间点，导致鉴定出一些由 L. asiaticus 调节的宿主基因，以及编码潜在效应蛋白的细菌基因。已确定的靶标和效应蛋白是开发新管理策略的潜在靶标，这些策略旨在干扰该病原体对木虱载体的成功利用。