Multiple horizontal acquisitions of plant genes in the whitefly Bemisia tabaci

Abstract

The extent to which horizontal gene transfer (HGT) has shaped eukaryote evolution remains an open question. Two recent studies reported four plant-like genes acquired through two HGT events by the whitefly Bemisia tabaci, a major agricultural pest (Lapadula et al. 2020; Xia et al. 2021). Here, we uncovered a total of 49 plant-like genes deriving from at least 24 independent HGT events in the genome of the MEAM1 whitefly. Orthologs of these genes are present in three cryptic B. tabaci species, they are phylogenetically nested within plant sequences, and expressed and under purifying selection. The predicted functions of these genes suggest that most of them are involved in plant-insect interactions. Thus, substantial plant-to-insect HGT may have facilitated the evolution of B. tabaci towards adaptation to a large host spectrum. Our study shows that eukaryote-to-eukaryote HGT may be relatively common in some lineages and it provides new candidate genes that may be targeted to improve current control strategies against whiteflies.