Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Plant Virus Department, Braunschweig, Germany.
J Virol. 2012 Dec;86(24):13241-52. doi: 10.1128/JVI.00880-12. Epub 2012 Sep 26.
The whitefly Bemisia tabaci (Gennadius) is a major cosmopolitan pest capable of feeding on hundreds of plant species and transmits several major plant viruses. The most important and widespread viruses vectored by B. tabaci are in the genus Begomovirus, an unusual group of plant viruses owing to their small, single-stranded DNA genome and geminate particle morphology. B. tabaci transmits begomoviruses in a persistent circulative nonpropagative manner. Evidence suggests that the whitefly vector encounters deleterious effects following Tomato yellow leaf curl virus (TYLCV) ingestion and retention. However, little is known about the molecular and cellular basis underlying these coevolved begomovirus-whitefly interactions. To elucidate these interactions, we undertook a study using B. tabaci microarrays to specifically describe the responses of the transcriptomes of whole insects and dissected midguts following TYLCV acquisition and retention. Microarray, real-time PCR, and Western blot analyses indicated that B. tabaci heat shock protein 70 (HSP70) specifically responded to the presence of the monopartite TYLCV and the bipartite Squash leaf curl virus. Immunocapture PCR, protein coimmunoprecipitation, and virus overlay protein binding assays showed in vitro interaction between TYLCV and HSP70. Fluorescence in situ hybridization and immunolocalization showed colocalization of TYLCV and the bipartite Watermelon chlorotic stunt virus virions and HSP70 within midgut epithelial cells. Finally, membrane feeding of whiteflies with anti-HSP70 antibodies and TYLCV virions showed an increase in TYLCV transmission, suggesting an inhibitory role for HSP70 in virus transmission, a role that might be related to protection against begomoviruses while translocating in the whitefly.
烟粉虱（Bemisia tabaci）是一种重要的世界性害虫，能够取食数百种植物，并传播几种主要的植物病毒。烟粉虱传播的最重要和最广泛的病毒属于双生病毒科，这是一组由于其小的、单链 DNA 基因组和孪生颗粒形态而异常的植物病毒。烟粉虱以持续循环非增殖的方式传播双生病毒。有证据表明，烟粉虱在摄入和保留番茄黄曲叶病毒（TYLCV）后会遭受有害影响。然而，对于这些共同进化的双生病毒-烟粉虱相互作用的分子和细胞基础知之甚少。为了阐明这些相互作用，我们使用烟粉虱微阵列进行了一项研究，专门描述了 TYLCV 获得和保留后整只昆虫和解剖中肠转录组的反应。微阵列、实时 PCR 和 Western blot 分析表明，烟粉虱热休克蛋白 70（HSP70）特异性响应单分体 TYLCV 和双分体南瓜卷曲病毒的存在。免疫捕获 PCR、蛋白共免疫沉淀和病毒覆盖蛋白结合测定显示 TYLCV 和 HSP70 之间在体外相互作用。荧光原位杂交和免疫定位显示 TYLCV 和双分体西瓜曲叶病毒病毒粒子与 HSP70 在中肠上皮细胞内共定位。最后，用抗 HSP70 抗体和 TYLCV 病毒粒子进行膜饲养烟粉虱表明 TYLCV 的传播增加，这表明 HSP70 在病毒传播中起抑制作用，这种作用可能与在烟粉虱体内转运时保护双生病毒有关。
