Isolation and Antifungal Activity of Plant Lectins against some Plant Pathogenic Fungi

Soad F. E. Mohsen , Moustafa A. Abbassy, Entsar I. Rabea, Hamdy K Abou-Taleb

Two lectins from seeds of white kidney bean (Phaseoulus vulgaries) and Soybean (Glycine max) were isolated and purified from saline crude extracts of seeds using ammonium sulfate precipitation. The two pure lectins were tested in vitro against two plant pathogenic fungi, Fusarium oxysporum and Rhizoctonia solani. Mycelial growth inhibition technique was performed in accordance with standard protocols to evaluate antifungal activity. Mycelial of both tested fungi were inhibited by the lectins extracts. Results revealed that, the lectin from Phaseoulus vulgaries (LP lectin) had a higher antifungal activity against F. oxysporum (EC50 = 5058, 4872 and 3617 mg/L, after 48, 72 and 120 h, respectively). Inaddition, the antifungal activity of LP lectin against R. solani was higher than lectin from Glycine max (LG lectin) with EC50 values 6786, 6646 and 5465 mg/L after 48, 72 and 120 h, respectively.

Keywords: Lectin, Phaseolus vulgaris, Glycine max, Antifungal activity, Fusarium oxysporum, Rhizoctonia solani.