Mining the secretome of the root-knot nematode Meloidogyne chitwoodi for candidate parasitism genes.

Parasite proteins secreted at the interface of nematode and host are believed to play an essential role in parasitism. Here, we present an efficient pipeline of bio-informatic algorithms and laboratory experiments to identify candidate parasitism genes within nematode secretomes, i.e.

Structural and functional characterization of a novel, host penetration-related pectate lyase from the potato cyst nematode Globodera rostochiensis.

SUMMARY The cell wall, a strong extraprotoplasmic layer surrounding plant cells that mainly consists of a variety of polysaccharides, constitutes a major barrier for potential parasites. Plant-parasitic nematodes are well equipped to overcome this barrier as they produce and secrete cell-wall-degrading enzymes. Expression profiling of various life stages of the potato cyst nematode Globodera rostochiensis revealed a novel pectate lyase gene (Gr-pel2, 759 bp).

A symbiont-independent endo-1,4-beta-xylanase from the plant-parasitic nematode Meloidogyne incognita.

Substituted xylan polymers constitute a major part of the hemicellulose fraction of plant cell walls, especially in monocotyledons. Endo-1,4-beta-xylanases (EC 3.2.

Origin, distribution and 3D-modeling of Gr-EXPB1, an expansin from the potato cyst nematode Globodera rostochiensis.

Southern analysis showed that Gr-EXPB1, a functional expansin from the potato cyst nematode Globodera rostochiensis, is member of a multigene family, and EST data suggest expansins to be present in other plant parasitic nematodes as well. Homology modeling predicted that Gr-EXPB1 domain 1 (D1) has a flat beta-barrel structure with surface-exposed aromatic rings, whereas the 3D structure of Gr-EXPB1-D2 was remarkably similar to plant expansins. Gr-EXPB1 shows highest sequence similarity to two extracellular proteins from saprophytic soil-inhabiting Actinobacteria, and includes a bacterial type II carbohydrate-binding module.

Plant degradation: a nematode expansin acting on plants.

Expansin proteins, which have so far been identified only in plants, rapidly induce extension of plant cell walls by weakening the non-covalent interactions that help to maintain their integrity. Here we show that an animal, the plant-parasitic roundworm Globodera rostochiensis, can also produce a functional expansin, which it uses to loosen cell walls when invading its host plant. As this nematode is known to be able to disrupt covalent bonds in plant cell walls, its accompanying ability to loosen non-covalent bonds challenges the prevailing view that animals are genetically poorly equipped to degrade plant cell walls.