Julius Kühn Institute (JKI) - Federal Research Centre for Cultivated Plants, Institute for Biological Control, Heinrichstr. 243, 64287 Darmstadt, Germany.
J Gen Virol. 2021 Mar;102(3). doi: 10.1099/jgv.0.001566. Epub 2021 Feb 24.
The baculovirus Cydia pomonella granulovirus (CpGV) is a biocontrol agent used worldwide against the codling moth (CM), L., a severe pest in organic and integrated pome fruit production. Its successful application is increasingly challenged by the occurrence of CM populations resistant to commercial CpGV products. Whereas three types (I-III) of CpGV resistance have been identified, type I resistance compromising the efficacy of CpGV-M, the so-called Mexican isolate of CpGV, is assumed to be the most widely distributed resistance type in Central Europe. Despite the wide use of CpGV products as biocontrol agents, little information is available on gene-expression levels in CM larvae. In this study, the transcriptome of CpGV-M infecting susceptible (CpS) and resistant (CpRR1) CM larvae was analysed at 24, 48, 72, 96 and 120 hours post infection in the midgut and fat body tissue by using a newly developed microarray covering all ORFs of the CpGV genome. According to their transcript abundance, the CpGV genes were grouped into four temporal clusters to which groups of known and unknown function could be assigned. In addition, sets of genes differentially expressed in the midgut and fat body were found in infected susceptible CpS larvae. For the resistant CpRR1 larvae treated with CpGV-M, viral entry in midgut cells could be confirmed from onset but a significantly reduced gene expression, indicating that type I resistance is associated with a block of viral gene transcription and replication.
小菜蛾颗粒体病毒（CpGV）是一种在世界范围内用于防治苹果蠹蛾（CM）的生物防治剂，CM 是有机和综合苹果生产中的严重害虫。其成功应用越来越受到 CM 种群对商业 CpGV 产品产生抗性的挑战。尽管已经确定了三种类型（I-III）的 CpGV 抗性，但 I 型抗性使 CpGV-M 的功效受损，而 CpGV-M 通常被称为 CpGV 的墨西哥分离株，被认为是中欧分布最广泛的抗性类型。尽管 CpGV 产品作为生物防治剂被广泛使用，但有关 CM 幼虫中基因表达水平的信息却很少。在这项研究中，通过使用一种新开发的覆盖 CpGV 基因组所有 ORF 的微阵列，在感染后 24、48、72、96 和 120 小时，分析了感染敏感（CpS）和抗性（CpRR1）CM 幼虫的 CpGV-M 中肠和脂肪体组织中的转录组。根据它们的转录丰度，CpGV 基因被分为四个时间聚类，其中可以分配到具有已知和未知功能的组。此外，还发现了在感染的敏感 CpS 幼虫中中肠和脂肪体中差异表达的基因集。对于用 CpGV-M 处理的抗性 CpRR1 幼虫，从一开始就可以确认病毒进入中肠细胞，但基因表达显著降低，表明 I 型抗性与病毒基因转录和复制的阻断有关。
