Citrus leprosis is the most important viral disease affecting citrus. The disease is caused predominantly by CiLV-C and is transmitted by Brevipalpus yothersi Baker mites. This study brings some insight into the colonization of B. yothersi in citrus [(Citrus × sinensis (L.) Osbeck (Rutaceae)] previously infested by viruliferous or non-viruliferous B. yothersi. It also assesses the putative role of shelters on the behavior of B. yothersi. Expression of PR1 and PR4 genes, markers of plant defense mechanisms, were evaluated by RT-qPCR to correlate the role of the plant hormonal changes during the tri-trophic virus-mite-plant interplay. A previous infestation with either non-viruliferous and viruliferous mites positively influenced oviposition and the number of adult individuals in the resulting populations. Mite populations were higher on branches that had received a previous mite infestation than branches that did not. There was an increase in the expression of PR4, a marker gene in the jasmonic acid (JA) pathway, in the treatment with non-viruliferous mites, indicating a response from the plant to their feeding. Conversely, an induced expression of PR1, a marker gene in the salicylic acid (SA) pathway, was observed mainly in the treatment with viruliferous mites, which suggests the activation of a plant response against the pathogen. The earlier mite infestation, as well as the presence of leprosis lesions and a gypsum mixture as artificial shelters, all fostered the growth of the B. yothersi populations after the second infestation, regardless of the presence or absence of CiLV-C. Furthermore, it is suggested that B. yothersi feeding actually induces the JA pathway in plants. At the same time, the CiLV-C represses the JA pathway and induces the SA pathway, which benefits the mite vector.

柑橘麻风病是影响柑橘的最重要的病毒性疾病。该疾病主要由 CiLV-C 引起，并由Brevipalpus yothersi Baker 螨传播。这项研究对B. yothersi在柑橘 [( Citrus × sinensis (L.) Osbeck (Rutaceae)] 中的定殖提供了一些见解，这些柑橘先前被带病毒或非带病毒的B. yothersi侵染。它还评估了庇护所对B. yothersi的行为。通过 RT-qPCR 评估植物防御机制标记PR1和PR4基因的表达，以关联三营养病毒-螨-植物相互作用期间植物激素变化的作用。无论是无毒螨还是有毒螨，都会对产卵和由此产生的群体中成虫的数量产生积极影响。之前受过螨虫侵染的树枝上的螨虫数量比没有受过螨虫侵扰的树枝上的要高。PR4 的表达有所增加，茉莉酸 (JA) 途径中的标记基因，在用无毒螨处理时，表明植物对其取食的反应。相反，水杨酸 (SA) 途径中的标记基因PR1的诱导表达，主要是在用有毒螨进行处理时观察到的，这表明植物对病原体的反应被激活。无论是否存在 CiLV-C，早期的螨虫感染以及麻风病灶和作为人工庇护所的石膏混合物的存在，都促进了第二次感染后B. yothersi种群的生长。此外，表明B. yothersi摄食实际上诱导了植物中的 JA 途径。同时，CiLV-C 抑制 JA 途径并诱导 SA 途径，这有利于螨媒介。