Membrane systems at the host-arbuscular mycorrhizal fungus interface (Nature Plants) ($)

In the arbuscular mycorrhizal fungal interaction with plants, the fungal partner promotes nutrient acquisition in exchange for some sugar and fatty acids from host plants. This exchange occurs at the symbiotic interface in the plant cortical cells where fungal hyphae form special branched structure called arbuscules, which are enveloped by host-derived peri-arbuscular membranes (PAM). Two ultrastructural studies by Ivanov et al. (2019) and Roth et al. (2019) analysed arbuscular structures in plant cortical cells using high resolution transmission electron microscopy tomography and three dimensional structural reconstruction. Both studies revealed vesicular and tubular compartments within the matrix of the peri-arbuscular space, irrespective of the plant-fungal system studied, as well as novel tubular structure originating from the fungal cells and present exclusively in the arbuscules. The functional relevance of these structures is yet to be confirmed. (Summary by Mugdha Sabale). Nature Plants 10.1038/s41477-019-0365-4 and 10.1038/s41477-019-0364-5