Does transgenic Cry1Ac + CpTI cotton pollen affect hypopharyngeal gland development and midgut proteolytic enzyme activity in the honey bee Apis mellifera L. (Hymenoptera, Apidae)?
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The transgenic Cry1Ac (Bt toxin) + CpTI (Cowpea Trypsin Inhibitor) cotton cultivar CCRI41 is increasingly used in China and potential side effects on the honey bee Apis mellifera L. have been documented recently. Two studies have assessed potential lethal and sublethal effects in young bees fed with CCRI41 cotton pollen but no effect was observed on learning capacities, although lower feeding activity in exposed honey bees was noted (antifeedant effect). The present study aimed at providing further insights into potential side effects of CCRI41 cotton on honey bees. Emerging honey bees were exposed to different pollen diets using no-choice feeding protocols (chronic exposure) in controlled laboratory conditions and we aimed at documenting potential mechanisms underneath the CCRI41 antifeedant effect previously reported. Activity of midgut proteolytic enzyme of young adult honey bees fed on CCRI41 cotton pollen were not significantly affected, i.e. previously observed antifeedant effect was not linked to disturbed activity of the proteolytic enzymes in bees’ midgut. Hypopharyngeal gland development was assessed by quantifying total extractable proteins from the glands. Results suggested that CCRI41 cotton pollen carries no risk to hypopharyngeal gland development of young adult honey bees. In the two bioassays, honey bees exposed to 1 % soybean trypsin inhibitor were used as positive controls for both midgut proteolytic enzymes and hypopharyngeal gland proteins quantification, and bees exposed to 48 ppb (part per billion) (i.e. 48 ng g−1) imidacloprid were used as controls for exposure to a sublethal concentration of toxic product. The results show that the previously reported antifeedant effect of CCRI41 cotton pollen on honey bees is not linked to effects on their midgut proteolytic enzymes or on the development of their hypopharyngeal glands. The results of the study are discussed in the framework of risk assessment of transgenic crops on honey bees.
KeywordsHypopharyngeal gland Midgut enzymes Risk assessment Sublethal effects Imidacloprid Transgenic cotton pollen
We are grateful to Xiaoxia Dong, Shifeng Yu and Haixia Yang for technical help for the dissection works on honey bees during the study, and to JB Yang for technical assistance for honey bee rearing. This work was supported by the National Natural Science Foundation of China (Grant No. 31071690). The authors declare that they have no conflict of interest.
- Abbott WS (1925) A method for computing the effectiveness of an insecticide. J Econ Entomol 18:265–267Google Scholar
- Bakhsh A, Rao AQ, Shahid AA, Husnain T, Riazuddin S (2010) Camv 35S is a developmental promoter being temporal and spatial in expression pattern of insecticidal genes (Cry1ac & Cry2a) in cotton. Aust J Basic Appl Sci 4:37–44Google Scholar
- Brittain C, Bommarco R, Vighi M, Barmaz S, Settele J, Potts SG (2010) The impact of an insecticide on insect flower visitation and pollination in an agricultural landscape. Agr For Entomol 12:259–266Google Scholar
- Clive J (2009) Global status of commercialized biotech/GM crops: 2009, The first fourteen years, 1996 to 2009. ISAAA brief no 41. ISAAA, Ithaca, NYGoogle Scholar
- Cui JJ (2003) Effects and mechanisms of the transgenic Cry1Ac plus CpTI (cowpea trypsin inhibitor) cotton on insect communities. Dissertation, Chinese Academy of Agricultural SciencesGoogle Scholar
- Decourtye A, Pham-Delègue MH (2002) The proboscis extension response: assessing the sublethal effects of pesticides on the honey bee. In: Devillers J, Pham-Delègue MH (eds) Honey Bees: Estimating the Environmental Impact of Chemicals. Taylor & Francis, London/New York, pp 67–81Google Scholar
- Hyams DG (1993) CurveExpert Software Version 1.38: A curve fitting system for windows, MississippiGoogle Scholar
- Lu YH, Wu KM, Jiang YY, Guo YY, Desneux N (2012) Widespread adoption of Bt cotton and insecticide decrease promotes biocontrol services. Nature 487:362–365Google Scholar
- Michener CD (1974) The social behavior of the bees: a comparative study. Harvard University Press, CambridgeGoogle Scholar
- Rui YK, Wang BM, Li ZH, Duan LS, Tian XL, Zhai ZX, He ZP (2004) Development of an enzyme immunoassay for the determination of the cowpea trypsin inhibitor (CpTI) in transgenic crop. Sci Agric Sin 37:1575–1579Google Scholar
- SAS Institute (1999) SAS/Stat user’s guide, release 8 edn. SAS Institute, Cary, NCGoogle Scholar
- Wratten SD, Gillespie M, Decourtye A, Mader E, Desneux N (2012) Pollinator habitat enhancement: benefits to other ecosystem services. Agr Ecosyst Environ doi: 10.1016/j.agee.2012.06.020