PCR-based cloning of four B-1,4-endoglucanases from the root-lesion nematode Pratylenchus vulnus

Endo-1,4-?-glucanases have been found in numerous plant-parasitic nematodes (PPN) and play key roles in nematode--plant interactions. Four ?-1,4-endoglucanase encoding transcripts were cloned and characterised in the root-lesion nematode Pratylenchus vulnus. The P. vulnus endoglucanases show high similarity to other endoglucanases found in other nematodes belonging to glycosyl hydrolase family 5 (GHF5). All deduced proteins from the cloned sequences contained the predicted signal peptide for secretion and three of the four endoglucanases did not contain a carbohydrate-binding module (CBM). Real-time PCR experiments suggested that two of endoglucanase transcripts are expressed through the second-stage juveniles (J2), J3--J4 juveniles, males, and the adult females at different amounts confirming that all life stages are able to penetrate the host plant. In-situ hybridisation showed that both transcripts of endo-1,4-?-glucanases accumulated specifically in the pharyngeal subventral gland cells of all P. vulnus stages, thus suggesting the parasitic behaviour of each life stage. Recent data on these characterised genes will be presented and discussed.