Genomic characterisation of the effector complement of the potato cyst nematode Globodera pallida
Abstract
Background: The potato cyst nematode Globodera pallida has biotrophic interactions with its host. The nematode induces a feeding structure - the syncytium - which it keeps alive for the duration of the life cycle and on which it depends for all nutrients required to develop to the adult stage. Interactions of G. pallida with the host are mediated by effectors, which are produced in two sets of gland cells. These effectors suppress host defences, facilitate migration and induce the formation of the syncytium. Results: The recent completion of the G. pallida genome sequence has allowed us to identify the effector complement from this species. We identify 128 orthologues of effectors from other nematodes as well as 117 novel effector candidates. We have used in situ hybridisation to confirm gland cell expression of a subset of these effectors, demonstrating the validity of our effector identification approach. We have examined the expression profiles of all effector candidates using RNAseq; this analysis shows that the majority of effectors fall into one of three clusters of sequences showing conserved expression characteristics (invasive stage nematode only, parasitic stage only or invasive stage and adult male only). We demonstrate that further diversity in the effector pool is generated by alternative splicing. In addition, we show that effectors target a diverse range of structures in plant cells, including the peroxisome. This is the first identification of effectors from any plant pathogen that target this structure. Conclusion: This is the first genome scale search for effectors, combined to a life-cycle expression analysis, for any plant-parasitic nematode. We show that, like other phylogenetically unrelated plant pathogens, plant parasitic nematodes deploy hundreds of effectors in order to parasitise plants, with different effectors required for different phases of the infection process.
Citation
Thorpe , P , Mantelin , S , Cock , P JA , Blok , V C , Coke , M C , Eves-van den Akker , S , Guzeeva , E , Lilley , C J , Smant , G , Reid , A J , Wright , K M , Urwin , P E & Jones , J T 2014 , ' Genomic characterisation of the effector complement of the potato cyst nematode Globodera pallida ' , BMC Genomics , vol. 15 , 923 . https://doi.org/10.1186/1471-2164-15-923
Publication
BMC Genomics
Status
Peer reviewed
ISSN
1471-2164Type
Journal article
Description
This project was funded through BBSRC grants BB/F00334X/1 and BB/H000801/1, Scottish Government Contract Research Fund project CRF0926 and through a BBSRC CASE award for which the industrial partner was Mylnefield Research Services. The James Hutton Institute receives funding from the Scottish Government. EG was funded through ERASMUS MUNDUS programme 2008–102 (EUMAINE).Collections
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