Nutritional Relationship betweenBemisia tabaciand Its Primary Endosymbiont,Portiera aleyrodidarum, during Host Plant Acclimation

Simple Summary Plant sap-sucking insects commonly have established mutualistic relationships with bacteria that live within their bodies and often provide nutrients that are lacking in the insect's diet. The sweet potato whitefly (Bemisia tabaci) harbors one primary and up to seven secondary endosymbiotic bacteria. The primary endosymbiont ofB. tabaciis already known to play a critical role in providing necessary nutrients forB. tabaci. Our objective was to study the relationship amongB. tabaci, its primary endosymbiont, and the host plant through the effects of host plant shifting and acclimation, that is, physiological adjustments as an insect becomes accustomed to a new host plant over several generations. The results showed that host shifting from Chinese kale to cotton plants led to a decrease in the fecundity ofB. tabaciin the first generation, which was restored after 10 generations of acclimation, and that its developmental time was also decreased by the tenth generation. Furthermore, essential amino acid biosynthesis genes of its primary endosymbiont were differentially regulated afterB. tabacihad become acclimated to cotton plants. We speculate that the primary endosymbiont has a close nutritional relationship withB. tabaciduring host plant acclimation. Plant sap-sucking insects commonly have established mutualistic relationships with endosymbiotic bacteria that can provide nutrients lacking in their diet.Bemisia tabaciharbors one primary endosymbiont,Portiera aleyrodidarum, and up to seven secondary endosymbionts, includingHamiltonella defensaandRickettsiasp.Portiera aleyrodidarumis already known to play a critical role in providing necessary nutrients forB. tabaci. In the present study, the relationship amongB. tabaci, its primary endosymbiont, and the host plant were examined through the effects of host plant shifting and acclimation.Bemisia tabaciwas transferred from Chinese kale to four different host plants, and the effects on both its performance and the expression levels of nutrient-related genes ofP. aleyrodidarumwere analyzed. The results showed that host shifting from Chinese kale to cotton plants led to a decrease in the performance ofB. tabaciin the first generation, which was restored after 10 generations of acclimation. Furthermore, the expression levels of essential amino acid biosynthesis genes ofP. aleyrodidarumwere found to be differentially regulated afterB. tabacihad acclimated to the cotton plants. Host plant shifting and acclimation to cucumber, poinsettia, and tomato plants did not affect the fecundity ofB. tabaciand the expression levels of most examined genes. We speculate thatP. aleyrodidarummay helpB. tabaciimprove its performance and acclimate to new hosts and thatP. aleyrodidarumhas a close nutritional relationship with its host during host plant acclimation.