The draft genome of whitefly Bemisia tabaci MEAM1, a global crop pest, provides novel insights into virus transmission, host adaptation, and insecticide resistance

Abstract

BackgroundThe whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is among the 100 worst invasive species in the world. As one of the most important crop pests and virus vectors, B. tabaci causes substantial crop losses and poses a serious threat to global food security.ResultsWe report the 615-Mb high-quality genome sequence of B. tabaci Middle East-Asia Minor 1 (MEAM1), the first genome sequence in the Aleyrodidae family, which contains 15,664 protein-coding genes. The B. tabaci genome is highly divergent from other sequenced hemipteran genomes, sharing no detectable synteny. A number of known detoxification gene families, including cytochrome P450s and UDP-glucuronosyltransferases, are significantly expanded in B. tabaci. Other expanded gene families, including cathepsins, large clusters of tandemly duplicated B. tabaci-specific genes, and phosphatidylethanolamine-binding proteins (PEBPs), were found to be associated with virus acquisition and transmission and/or insecticide resistance, likely contributing to the global invasiveness and efficient virus transmission capacity of B. tabaci. The presence of 142 horizontally transferred genes from bacteria or fungi in the B. tabaci genome, including genes encoding hopanoid/sterol synthesis and xenobiotic detoxification enzymes that are not present in other insects, offers novel insights into the unique biological adaptations of this insect such as polyphagy and insecticide resistance. Interestingly, two adjacent bacterial pantothenate biosynthesis genes, panB and panC, have been co-transferred into B. tabaci and fused into a single gene that has acquired introns during its evolution.ConclusionsThe B. tabaci genome contains numerous genetic novelties, including expansions in gene families associated with insecticide resistance, detoxification and virus transmission, as well as numerous horizontally transferred genes from bacteria and fungi. We believe these novelties likely have shaped B. tabaci as a highly invasive polyphagous crop pest and efficient vector of plant viruses. The genome serves as a reference for resolving the B. tabaci cryptic species complex, understanding fundamental biological novelties, and providing valuable genetic information to assist the development of novel strategies for controlling whiteflies and the viruses they transmit.Electronic supplementary materialThe online version of this article (doi:10.1186/s12915-016-0321-y) contains supplementary material, which is available to authorized users.

Genome‐wide identification and characterization of HSP gene superfamily in whitefly (Bemisia tabaci) and expression profiling analysis under temperature stress

“…The release of the recently completely sequenced genome of B. tabaci MEAM1 makes it possible to identify stress‐responsive related gene families through comparative genomics approaches (Chen et al ., ). In this study, we found 26 Hsp genes encoding four types of insect Hsp s in the B. tabaci genome by comprehensive bioinformatic methods.…”

Identification of glutathione S‐transferases in Bemisia tabaci (Hemiptera: Aleyrodidae) and evidence that GSTd7 helps explain the difference in insecticide susceptibility between B. tabaci Middle East‐Minor Asia 1 and Mediterranean

“…The Illumina reads of these libraries were submitted to the European Nucleotide Archive under the primary accession number PRJEB11628 and secondary accession numbers ERP013025 and SAMEA3643263‐SAMEA3643274; they were also deposited in the Sequence Read Archive database under accession number SRP064690. The genomic information of GST was from the published B.tabaci genomes (Chen et al ., ; Xie et al ., ). The candidate BtGST transcripts were confirmed by searching the BLASTX algorithm against the nonredundant NCBI nucleotide database using a cut‐off E‐value of 10 −5 .…”

Genome‐wide analysis of odorant‐binding proteins and chemosensory proteins in the sweet potato whitefly, Bemisia tabaci

“…A comprehensive understanding of OBPs and CSPs in B. tabaci requires a more complete genome‐wide analysis. In this research, we used previously published data on B. tabaci genomes (Chen et al ., ; Xie et al ., ) and new antenna transcriptome data (obtained in the current study) to complete a genome‐wide analysis of OBP and CSP gene families in B. tabaci MEAM1. We systematically classified, characterized, and phylogenetically analyzed the OBP and CSP genes.…”