Subcellular localization of LjNIP1 in mycorrhizal roots. Confocal microscopy images showing pLjNIP-eGFP-LjNIP1 expression in L. japonicus roots colonized with Gi. margarita. pUBI10-DsRed was expressed ubiquitously in the transformed roots and highlighted the cell nuclei (n). A-C: pLjNIP1-eGFP-LjNIP1 is present inside the whole cell lumen, being associated to the surface of the fungal arbuscule branches (ab) in a non-continuous pattern. It also accumulated outside the cell nucleus, resulting associated to the inner cell membrane system and to the endoplasmic reticulum (er). D-E: non colonized cortical cells from mycorrhizal plants; the nucleus (n) is in the typical peripheral position; the absence of LjNIP1 expression, is revealed by the absence of any GFP signal, as shown also by the longitudinal section of a non colonized root where no GFP signal was detected (F) and DsRed was ubiquitously expressed (G). Bars = 25 μm.