University of Hertfordshire

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Original languageEnglish
JournalPLoS Pathogens
Publication statusSubmitted - 4 Oct 2021

Abstract

Plant-parasitic nematodes are a globally important constraint on crop production which have been controlled using nematicides; these are highly toxic and legislation in Europe and elsewhere is prohibiting their use and alternatives are being sought. Pasteuria penetrans and P. nishizawae are hyperparasitic bacteria that form endospores and have the potential to control both cyst (Heterodera and Globodera spp.) and root-knot nematodes (Meloidogyne spp.), but their attachment to the cuticle of nematodes is highly host-specific. Understanding the nature of this interaction has relied upon studying loss of function in natural populations using immunological and biochemical approaches. Phylogenetic analysis of genes identified in a survey sequence has shown P. penetrans to be closely related to Bacillus and to have a diverse range of collagen-like fibres which we hypothesise to be involved in the endospore attachment process. However, due to the obligately hyperparasitic nature of Pasteuria species, identifying and characterising the collagenous-like proteins through gain of function has proved difficult and a new approach is required. Here, using antibodies raised to synthetic collagen-like peptides based on Pasteuria collagen-like genes, we undertake a comparative study of endospores between Pasteuria penetrans and the more easily cultured Lepidopteran pathogen Bacillus thuringiensis with the aim of seeing if it could be used as a gain of function model substitute. We identify several similar proteins between P. penetrans and B. thuringiensis of which two proteins, one >250 kDa and another ~72 kDa, are glycosylated with N-acetylglucosamine and both of which are digested if treated with collagenase; these treatments also affect endospore attachment orientation. We suggest these collagen-like surface proteins are involved in adhesion of the endospores to the cuticle of the host nematode as the first stage of infection process. Further, we hypothesise that as B. thuringiensis is relatively easy to culture, it could be developed as a model for studying the role of the collagen-like adhesins from Pasteuria in endospore attachment.

ID: 26135907