Selective and stable elimination of endosymbionts from multiple-infected whitefly Bemisia tabaci by feeding on a cotton plant cultured in antibiotic solutions

The maternally heritable endosymbiont provides many ecosystem functions.Antibiotic elimination of a specific symbiont and establishment of experimental host lines lacking certain symbionts enable the roles of a given symbiont to be explored.The whitefly Bemisia tabaci(Gennadius)in China harbors obligate symbiont Portiera infecting each in-dividual,as well as facultative symbionts,such as Hamiltonella,Rickettsia and Cardinium,with co-infections occurring relatively frequently.So far no studies have evaluated the selectivity and efficacy of a specific symbiont elimination using antibiotics in whiteflies co-infected with different symbionts.Furthermore,no success has been achieved in estab-lishing certain symbiont-free B.tabaci lines.In this study,we treated Hamiltonella infected B.tabaci line,Hamiltonella-Rickettsia-co infected line and Hamiltonella-Cardinium co-infected line by feeding B.tabaci adults with cotton plants cultured in water containing ri-fampicin,ampicillin or a mixture of them,aiming to selectively curing symbiont infections and establishing stable symbiont-free lines.We found ampicillin selectively eliminated Cardinium without afecting Portiera,Hamiltonella and Rickettsia,although they coex-isted in the same host body.Meanwhile,all of the symbionts considered in our study can be removed by rifampicin.The reduction of facultative symbionts occurred at a much quicker pace than obligate symbiont Portiera during rifampicin treatment.Also,we measured the stability of symbiont elimination in whitefly successive generations and established Rickettsia-infected and Cardinium-infected lines which are absent in natural populations.Our results provide new protocols for selective elimination of symbionts co-existing in a host and establishment of different symbiont-infected host lines.