Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, Queensland, Australia.
Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, United States of America.
PLoS One. 2018 Dec 7;13(12):e0208538. doi: 10.1371/journal.pone.0208538. eCollection 2018.
Thrips palmi is a widely distributed major agricultural pest in the tropics and subtropics, causing significant losses in cucurbit and solanaceous crops through feeding damage and transmission of tospoviruses. Thrips palmi is a vector of capsicum chlorosis virus (CaCV) in Australia. The present understanding of transmission biology and potential effects of CaCV on T. palmi is limited. To gain insights into molecular responses to CaCV infection, we performed RNA-Seq to identify thrips transcripts that are differentially-abundant during virus infection of adults. De-novo assembly of the transcriptome generated from whole bodies of T. palmi adults generated 166,445 contigs, of which ~24% contained a predicted open reading frame. We identified 1,389 differentially-expressed (DE) transcripts, with comparable numbers up- (708) and down-regulated (681) in virus-exposed thrips compared to non-exposed thrips. Approximately 59% of these DE transcripts had significant matches to NCBI non-redundant proteins (Blastx) and Blast2GO identified provisional functional categories among the up-regulated transcripts in virus-exposed thrips including innate immune response-related genes, salivary gland and/or gut-associated genes and vitellogenin genes. The majority of the immune-related proteins are known to serve functions in lysosome activity and melanisation in insects. Most of the up-regulated oral and extra-oral digestion-associated genes appear to be involved in digestion of proteins, lipids and plant cell wall components which may indirectly enhance the likelihood or frequency of virus transmission or may be involved in the regulation of host defence responses. Most of the down-regulated transcripts fell into the gene ontology functional category of 'structural constituent of cuticle'. Comparison to DE genes responsive to tomato spotted wilt virus in Frankliniella occidentalis indicates conservation of some thrips molecular responses to infection by different tospoviruses. This study assembled the first transcriptome in the genus Thrips and provides important data to broaden our understanding of networks of molecular interactions between thrips and tospoviruses.
棕榈蓟马是热带和亚热带地区广泛分布的主要农业害虫，通过取食危害和传播番茄斑萎病毒（Tospoviruses），给葫芦科和茄科作物造成重大损失。棕榈蓟马是澳大利亚辣椒褪绿病毒（CaCV）的传播媒介。目前对其传播生物学和 CaCV 对棕榈蓟马潜在影响的了解有限。为了深入了解 CaCV 感染的分子反应，我们进行了 RNA-Seq，以鉴定成虫感染病毒期间差异丰度的蓟马转录本。从棕榈蓟马成虫全虫体转录组的 de-novo 组装生成了 166445 个 contigs，其中约 24%包含预测的开放阅读框。我们鉴定了 1389 个差异表达（DE）转录本，与未暴露于病毒的蓟马相比，暴露于病毒的蓟马中有相当数量的转录本上调（708 个）和下调（681 个）。这些 DE 转录本中约 59%与 NCBI 非冗余蛋白（Blastx）有显著匹配，Blast2GO 鉴定出暴露于病毒的蓟马中上调转录本的临时功能类别，包括先天免疫反应相关基因、唾液腺和/或肠道相关基因和卵黄原基因。大多数与免疫相关的蛋白质被认为在昆虫的溶酶体活性和黑化中发挥作用。大多数上调的与口腔和口腔外消化相关的基因似乎参与蛋白质、脂质和植物细胞壁成分的消化，这可能间接增加病毒传播的可能性或频率，或者可能参与宿主防御反应的调节。大多数下调的转录本属于基因本体功能类别“表皮结构成分”。与弗兰克氏西罗利线虫中对番茄斑萎病毒有反应的 DE 基因进行比较表明，一些蓟马对不同的 Tospoviruses 感染的分子反应具有保守性。本研究组装了蓟马属的第一个转录组，并提供了重要数据，以扩大我们对蓟马和 Tospoviruses 之间分子相互作用网络的理解。
