Top left, cytosolic-free calcium ion distribution in the elongation zone of a barley root loaded with Oregon Green indicator and visualised with Fluorescence Lifetime Imaging by confocal microscopy (image supplied by Feifei Wang and the Western Sydney University Confocal Bio-Imaging Facility). Top right, false-coloured confocal image of in vitro germinated pollen from an Arabidopsis thaliana strain that lacks a functional version of the mechanosensitive ion channel MSL8. Expelled cytoplasm from bursting pollen appears blue, while callose (stained with aniline blue) appears white (see also Hamilton and Haswell 2017, pp. 1222-1237of this issue). Bottom left, confocal fluorescence image showing polar localization of diacylglycerol (DAG) in young bulging root hairs of 5-day old Arabidopsis seedlings expressing the DAG biosensor, 35S::YFP-C1aPKC (see Vermeer et al. 2017, pp. 1196-1207 of this issue). Bottom right, 3-D reconstruction of an Arabidopsis seedling root expressing the cytosolic localized calcium probe Cameleon YC3.6 imaged by means of light sheet microscopy. The image was obtained by combining 250 Z-stacks spaced every 1.48 µm and is shown in false colours (Green Fire Blue-lut)(see Candeo et al. 2017, pp. 1161-1172 of this issue).