
This month the inset cover image shows a detail of the stigma of a flower of apple, Malus × domestica. The acquisition of stigmatic receptivity is concomitant with secretion of arabinogalactan proteins (AGPs, strained green) into the intercellular spaces between cell walls (blue). The presence of AGPs in the pistil has been shown in divergent species, from monocots and eudicots to early-divergent angiosperms, and hence this finding opens a way for an understanding of glycoprotein evolution modulating pollen–pistil interactions in angiosperms. See Losada and Herrero.
