Investigation of carbohydrate binding property of a fungal lectin from Xerocomus chrysenteron and potential use on Myzus persicae aphid.

In recent years encoding insecticidal Lectins have been suggested as one of the promising methods against insect pests and have been engineered successfully into a variety of crops including wheat, rice, tobacco and potatoes. Xerocomus chrysenteron Lectin (XCL) has a high hemagglutinating activity and results obtained from sugar specificity assay showed to have specific affinity to Galactose and N-Acetylgalactosamine (GalNAc). In previous studies, XCL was shown to have negative effects on some insect pests, including aphids. In the present study, the effects of different carbohydrates including D-glucose, D-mannose, D-galactose and GalNAc, associated with 0.1% XCL (w/v) in artificial diet was investigated to assess the evolution of the lectin toxicity toward Myzus persicae aphid during 7 days. M. persicae, a polyphagous aphid, showed no significant differences of mortality when fed with the XCL lectin associated with Glucose and Mannose or fed on XCL diet only. At the opposite, the mortality rates related to artificial diet supplemented with Galactose or GalNAc and XCL were significantly reduced. There was then a significant mortality difference between M. persicae fed on an artificial diet incorporated specific carbohydrate binding Lectin with those fed with lectin only. The potential use of this particular fungal Lectin (XCL) with more specific carbohydrate binding will be discussed in relation to the development of bio-insecticide and integrated pest management.