"Application of array tomography to elucidate nuclear clustering architecture in giant-feeding cells induced by root-knot nematodes"

Abstract :

"Plant-parasitic nematodes like root-knot nematodes (RKN; Meloidogyne spp.) cause great losses in agriculture by inducing root swellings, named galls, in host roots disturbing plant growth and development. Previous 2D studies using different microscopy techniques revealed the presence of numerous nuclear clusters in nematodes-induced giant cells within galls.

We will show in 3D that nuclear clustering occurring in giant cells revealed to be much more complex, illustrating subclusters built of multiple nuclear lobes. These nuclear subclusters were unveiled to be interconnected and likely communicate via nucleotubes highlighting the potential relevance of this nuclear transfer for disease. As well, microtubules and microtubules organizing centers are profusely present between the densely packed nuclear lobes suggesting that the cytoskeleton might be involved in anchoring nuclear clusters in giant cells.

We show in this study that it is possible to apply volume EM approaches such as array tomography on roots infected by nematodes using basic equipment found in most electron microscopy facilities. The application of array tomography was valuable to observe the cellular ultrastructure revealing a remarkable nuclear architecture in 3D of giant cells in the model host Arabidospsis thaliana.

We believe that the discovery of nucleotubes, as a unique component of nuclear clusters present in giant cells, can be potentially exploited as a novel strategy to develop alternative approaches for root-knot nematode control in crop species."