Enzyme-Activities Associated With Salivary-Glands of the Froghopper Eoscarta-Carnifex (F) (Homoptera, Cercopoidae) - Possible Role of Salivary Catalase in Phytotoxicity

Abstract

'Froghopper blight', systemic damage caused by an unidentified toxin in the saliva of various homopterans (superfamily Cercopoidea), is responsible for massive yield losses in many sugarcane-growing areas of the New World. The nature of the toxin remains unclear. In addition to lipases and several glycosidases, extracts of salivary glands of the Australian froghopper Eoscarta carnifex (F.) were found to contain high levels of catalase. The insect catalase was shown to inhibit plant peroxidase in vitro; peroxidases are induced by wounding and are central to many of the major injury responses of the plant. We hypothesise that the role of the salivary catalase in E. carnifex may be in scavenging peroxide, thus suppressing the plant injury response.