Binding of insecticidal lectin Colocasia esculenta tuber agglutinin (CEA) to midgut receptors of Bemisia tabaci and Lipaphis erysimi provides clues to its insecticidal potential

Abstract

The insecticidal potential of Galanthus nivalis agglutinin-related lectins against hemipterans has been experimentally proven. However, the basis behind the toxicity of these lectins against hemipterans remains elusive. The present study elucidates the molecular basis behind insecticidal efficacy of Colocasia esculenta tuber agglutinin (CEA) against Bemisia tabaci and Lipaphis erysimi. Confocal microscopic analyses highlighted the binding of 25 kDa stable homodimeric lectin to insect midgut. Ligand blots followed by LC MS/MS analyses identified binding partners of CEA as vacuolar ATP synthase and sarcoplasmic endoplasmic reticulum type Ca(2+) ATPase from B. tabaci, and ATP synthase, heat shock protein 70 and clathrin heavy chain assembly protein from L. erysimi. Internalization of CEA into hemolymph was confirmed by Western blotting. Glycoprotein nature of the receptors was identified through glycospecific staining. Deglycosylation assay indicated the interaction of CEA with its receptors to be probably glycan mediated. Surface plasmon resonance analysis revealed the interaction kinetics between ATP synthase of B. tabaci with CEA. Pathway prediction study based on Drosophila homologs suggested the interaction of CEA with insect receptors that probably led to disruption of cellular processes causing growth retardation and loss of fecundity of target insects. Thus, the present findings strengthen our current understanding of the entomotoxic potentiality of CEA, which will facilitate its future biotechnological applications.

Legume Lectins: Proteins with Diverse Applications

“…In the case of insects lacking a PM, the insecticidal effect of lectins may be exerted by their direct interaction with glycoconjugates present on the cell epithelium [122]. In fact, the insecticidal activity of lectins relies on their binding properties to sugars present on the surface of the insect gut epithelial cells.…”

“…Such co-localization was proposed to occur via a carrier-receptor, ferritin. The internalization of the Colocasia esculenta tuber agglutinin into insect hemolymph also was demonstrated, suggesting it could interact with various N -glycosylated intracellular targets, which may, in part, explain the lectin toxicity [122]. Although the complete mechanism by which some lectins are able to cross midgut epithelial cells is not yet fully understood, available evidence has highlighted the implication of clathrin-mediated endocytosis as part of this process [123,124].…”

Itches—stimulating compounds from Colocasia esculenta (taro): bioactive-guided screening and LC–MS/MS identification

“…These activities together contribute to the insect-resistant function of lectins. 21,22 Proteins with lectin activity have been reported to exist in tuberous plant species and in taros there are mainly three: storage proteins, lectins and tarin. 1,23,24 Tarin is a glycoprotein with 2-3% carbohydrate content and shows a complex carbohydrate specificity, binding with high affinity to high-mannose and complex N-glycans which confers remarkable anti-tumor, anti-viral and insecticidal properties on tarin.…”

Anti-insect potential of a lectin from the tuber, Dioscorea mangenotiana towards Eldana saccharina (Lepidoptera: Pyralidae)

“…Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License anti-insect and anti-microbial, has been proposed on the basis of indirect and direct evidence (Sharma et al, 2004;Wong et al, 2010;Roy et al, 2014;Al Atalah et al, 2014). Thus, there is intensified research on the use of lectins in protecting crop plants from the attack of insects and fungal pathogens.…”