Assessment of sequence variability in putative parasitism factor, expansin (expB2) from diverse populations of potato cyst nematode Globodera rostochiensis

Expansins are a group of plant cell wall loosening proteins found among the parasitism factors or effectors of plant-parasitic nematodes. Molecular variability of the expansin B2 (expB2) gene and its predicted protein was evaluated in populations of the potato cyst nematode Globodera rostochiensis in order to find a link to the pathotypes of potato cyst nematodes. Although considerable variability was determined, no correlation could be established between these polymorphisms and pathotype classification. Our results suggest that some of the observed variability could be explained by the existence of a Gr-expB2 family with very similar intron lengths and positions.

► Considerable variability of expB2 gene determined in Globodera rostochiensis.
► expB2 is not accountable for differences between the G. rostochiensis pathotypes.
► Variability of expB2 within a single juvenile indicates existence of a gene family.