Entomologia Experimentalis et Applicata (1998) 86, 197-203

W. Tjallingii, Freddy Anna Urbanska, Anthony F.G. Dixon and Bogumil Leszczynski (1998)
Phenol oxidising enzymes in the grain aphid's saliva
Entomologia Experimentalis et Applicata 86 (2), 197-203
Abstract: Sucrose-agarose gels and sucrose liquid diets were used to study the phenol oxidising enzymes in the salivary secretions of the grain aphid, Sitobion avenae (Fabricius). Activity indicating the presence of two oxidoreductases, polyphenol oxidase (PPO) and peroxidase (Px), was found. Both enzymes were present in the aphid's stylet sheath (gelling saliva) but only polyphenol oxidase activity was found in the halos around sheaths and thus in watery saliva. Electrical penetration graphs (EPG) revealed that the secretion of these enzymes into the gels, by an individual aphid, was associated with its probing activity observed during penetration of the epidermal and mesophyll tissues. The grain aphid's PPO, secreted in its saliva reacted with a range of phenolic compounds. As most of these phenolics occur naturally in cereals, the grain aphid could modify its host-plant's phenolic composition. The importance of the grain aphid's polyphenol oxidase and peroxidase in detoxifying cereal phenolics is discussed.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Anthony F.G. Dixon

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Sitobion avenae