Fig. 3

Meristem structure and size of monocot rpk1-7 seedlings. a Median section of a seedling with SAM and insets showing a magnified series of sections through the SAM (that of the median section is framed). Stomata are separated by other epidermal cells (arrowheads). Note the seemingly terminal position of the cotyledon, while the vascular elements demonstrate a lateral origin. b An eSM seedling (left). Insets show magnifications with details (right): irregularly spaced stomata (top, arrowheads); a regularly shaped meristem with leaf primordia (middle); a further section few microns apart from the former (bottom). Arrows point towards the root. Scale bars: 100 μm (left parts of a and b) and 20 μm (insets). c Means and SDs of rpk1-7 seedlings with one, two irregularly sized and two normal cotyledons and of wild-type and the clv3 mutant respectively (brackets: numbers of seedlings analysed). d Representatives of the different seedlings (except irregular seedlings)