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Abstract

The plant cell cycle plays a key role in nematode feeding sites development but how precisely nematodes manipulate this machinery in their favour remains to be better comprehended. A systematic comparison of the temporal and spatial expression pattern of core cell cycle genes between galls and uninfected control roots of Arabidopsis thaliana resulted in the identification of a collection of genes up- or downregulated in nematode feeding sites. Their functional analyses resulted in the identification of a subset of genes strongly impairing gall development. We will present that two expressed cell cycle genes (ICKs/KRPs), named KRP2 and KRP6 exert distinct inhibitory functions disrupting gall development and consequently nematode reproduction. Ectopic KRP2 expression blocks mitosis in giant- and neighboring cells resulting in severely reduced gall size. In contrast, KRP6 overexpression induces mitosis resulting in larger galls containing undersized giant cells (GCs).  The latter is validated in tobacco BY2 cells strongly suggesting that KRP6 is involved in giant cell multinucleation. Finally, it is envisaged to use cell cycle inhibitor genes to engineer resistance in nematode plant hosts.