Submitted to: European Whitefly Symposium Proceedings
Publication Type: Abstract only
Publication Acceptance Date: 9/25/2008
Publication Date: 10/10/2008
Citation: Rosell, R.C., Shah, A., Khan, M., Aghakasiri, N., Shatters, R.G., Mckenzie, C.L. 2008. Temperature stress effects in Bemisia tabaci (Hemiptera: Aleyrodidae) type B whiteflies [abstract]. 3rd European Whitefly Symposium. Abstracts, p. 91. Interpretive Summary:
Technical Abstract: Oxidative stress occurs in response to changes in the redox equilibiurm, which may be caused by increases in reactive oxygen species (ROS), a decrease in antioxidant protection or failure of cells to repair oxidative damage. ROS are either free radicals, reactive molecules containing oxygen atoms or molecules that contain oxygen atoms that can produce free radicals. Superoxide molecules, a major type of ROS, initiate oxidative damage to phospholipids, proteins and nucleic acids. Under normal conditions, antioxidants such as superoxide dismutase (SOD), catalase, ascorbate peroxidase and glutathione peroxidase (GSH) remove ROS from cells. In insects, natural abiotic stresses cause the need for more energy to maintain homeostasis, which in turn increases oxidative stress. Particularly, changes in thermal conditions have been shown to affect insect life processes. The purpose of our study is to determine the relationship between temperature stress, begomovirus and oxidative stress in Bemisia tabaci whiteflies. Previously, we have shown the presence of SOD in Bemisia tabaci whole body extracts. Additionally, using two begomoviruses, tomato mottle virus (ToMoV) and tomato yellow leaf curl virus (TYLCV), we have determined effects of temperature stress on whiteflies fed 48 hrs on either begomovirus-infected tomato or healthy tomato plants. Our data showed that SOD activity was directly proportional to an increase in temperature in non-viruliferous whiteflies. However, SOD activity in whiteflies reared on virus-infected plants was varied. Further studies will focus on induction of other antioxidants, such as GSH, and activities of these enzymes in whiteflies with reduced numbers of endosymbionts.