Lin et al. examine expression of Brassica campestris male fertility 8 (BcMF8) in pistils of Chinese cabbage (B. campestris ssp. chinensis), and find that it encodes a putative AGP that is located in the cell wall and is expressed in pollen grains and pollen tubes.
How, in molecular terms, does the vital interaction between pollen pollen and pistil work?
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).