title: The endosymbiont Hamiltonella increases the growth rate of its host Bemisia tabaci during periods of nutritional stress.
abstract: The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) harbors several bacterial symbionts. Among the secondary (facultative) symbionts, Hamiltonella has high prevalence and high infection frequencies, suggesting that it may be important for the biology and ecology of its hosts. Previous reports indicated that Hamiltonella increases whitefly fitness and, based on the complete sequencing of its genome, may have the ability to synthesize cofactors and amino acids that are required by its host but that are not sufficiently synthesized by the host or by the primary endosymbiont, Portiera. Here, we assessed the effects of Hamiltonella infection on the growth of B. tabaci reared on low-, standard-, or high-nitrogen diets. When B. tabaci was reared on a standard-nitrogen diet, no cost or benefit was associated with Hamiltonella infection. But, if we reared whiteflies on low-nitrogen diets, Hamiltonella-infected whiteflies often grew better than uninfected whiteflies. Furthermore, nitrogen levels in field-collected whiteflies indicated that the nutritional conditions in the field were comparable to the low-nitrogen diet in our laboratory experiment. These data suggest that Hamiltonella may play a previously unrecognized role as a nutritional mutualist in B. tabaci.
authors.affiliation: College of Plant Protection, Hunan Agricultural University, Changsha, Hunan, People's Republic of China ; Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Su
authors.affiliation: Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
authors.forename: Wen
authors.initials: W
authors.lastname: Xie
authors.affiliation: Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
authors.forename: Shaoli
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
authors.forename: Qingjun
authors.initials: Q
authors.lastname: Wu
authors.affiliation: Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
authors.forename: Baiming
authors.initials: B
authors.lastname: Liu
authors.affiliation: Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Fang
authors.affiliation: Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
authors.forename: Baoyun
authors.initials: B
authors.lastname: Xu
authors.affiliation: Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
authors.forename: Youjun
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000704:Analysis of Variance; D000824:Animal Nutritional Physiological Phenomena / Q000502:physiology*; D000818:Animals; D002681:China; D004755:Enterobacteriaceae / Q000378:metabolism / Q000502:physiology*; D006430:Hemiptera / Q000254:growth & development* / Q000382:microbiology*; D009584:Nitrogen / Q000378:metabolism; D013312:Stress, Physiological / Q000502:physiology*; D013559:Symbiosis
chemical_list: D000596:Amino Acids; D009584:Nitrogen