Location: Vegetable ResearchTitle: Genome-wide profiles of miRNAs and piRNAs in whitefly Bemisia tabaci in response to feeding on tomato plants infected with tomato yellow leaf curl virus
|CHEN, WENBO - Bryce Thompson Institute|
|FEI, ZHANGJUN - Bryce Thompson Institute|
Submitted to: International Whitefly Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 7/16/2018
Publication Date: 9/15/2018
Citation: Hasegawa, D.K., Shamimuzzaman, M., Chen, W., Simmons, A.M., Fei, Z., Ling, K. 2018. Genome-wide profiles of miRNAs and piRNAs in whitefly Bemisia tabaci in response to feeding on tomato plants infected with tomato yellow leaf curl virus [abstract]. 3rd International Whitefly Symposium, Perth, Australia, September 16-19, 2018. p.18.
Technical Abstract: The whitefly Bemisia tabaci is a notorious vector transmitting hundreds of viruses that infect food and fiber crops worldwide. Recently, we sequenced the B. tabaci MEAM1 genome and profiled gene expression in whiteflies during feeding on tomato infected with Tomato yellow leaf curl virus (TYLCV). To investigate the regulatory mechanisms in whiteflies during TYLCV acquisition and transmission, we performed small RNA (sRNA) sequencing and conducted microRNA (miRNA) and Piwi-interacting RNA (piRNA) profiling of B. tabaci after feeding on TYLCV-infected or virus-free tomato for 24 h, 48 h and 72 h. A total of 160 miRNAs were identified, including 68 conserved and 92 novel miRNAs. Interestingly, only two miRNAs were differentially expressed in whiteflies that fed on TYLCV-infected or non-infected tomato, which had predicted targets to Bta05482 encoding a Nuclear receptor and Bta10702 encoding a very-long-chain (3R)-3-hydroxyacyl-CoA dehydratase, respectively. To shed light on the relationship between B. tabaci regulatory miRNAs and gene expression, we correlated the miRNA expression with gene expression derived from a transcriptome data that was generated from the same pool of RNAs. Interestingly, approximately half of miRNAs were correlated inversely with their predicted target transcript expression. In a separate analysis, piRNAs were clustered along the whitefly genome, which aggregated in 57 to 96 clusters in sRNA libraries prepared in three time points. Comparative analysis across the three time points identified 53 commonly expressed piRNA clusters. We also identified five TYLCV-induced and 24 TYLCV-suppressed piRNA clusters. About 62% of all identified piRNAs were derived from sequences in intergenic regions, introns and UTRs, while the remaining 38% from coding sequences (CDS) and repeat elements. Six protein-coding genes were targeted by the TYLCV-induced piRNAs, but their functions in anti-viral defence or virus transmission are not known. Transposable elements targeted by piRNA clusters include both class I retrotransposons (e.g., Gypsy, Copia, and LINEs) and class II DNA transposons (e.g., MITE, hAT, and TcMar). Together, we have tied miRNAs and piRNAs with genomic and transcriptomic information to provide an in-depth understanding on the underlying mechanisms of B. tabaci during virus acquisition and transmission, which might facilitate the identification of novel targets for RNAi control of whiteflies.