AgricultureBiochemistryMicrobiologyParasitologyPlant NematologyPlant-microbe InteractionsHost-nematode InteractionsNematode BiologyNematode PhysiologyNematode-plant InteractionsPlant-parasitic NematodesDefense Response MechanismsMolecular Recognition Of NematodesNematode-soil InteractionsParasitic NematodesPlant-nematode InteractionsPlant-parasitic Nematode DiagnosisSurface Coat Structure
Chemical composition, origin, and biological role of the surface coat (SC) of plant-parasitic nematodes are described and compared with those of animal-parasitic and free-living nematodes. The SC of the plant-parasitic nematodes is 5-30 nm thick and is characterized by a net negative charge. It consists, at least in part, of glycoproteins and proteins with various molecular weights, depending upon the nematode species. The lability of its components and the binding of human red blood cells to the surface of many tylenchid plant-parasitic nematodes, as well as the binding of several neoglycoproteins to the root-knot nematode Meloidogyne, suggest the presence of carbohydrate-recognition-domains for host plants and parasitic or predatory soil microorganisms (Pasteuria penetrans and Dactylaria spp., for example). These features may also assist in nematode adaptations to soil environments and to plant hosts with defense mechanisms that depend on reactions to nematode surfaces. Surface coat proteins can be species and race specific, a characteristic with promising diagnostic potential.