Cell separation is an important biological process in plants that is precisely regulated both spatially and temporally. Key separation events include abscission of organs such as leaves and fruit and dehiscence events such as pod shatter in canola and other Brassicas. Polygalacturonases (PGs) are enzymes essential for the degradation of pectin, an important component of the adhesive material between cells. Although there are around 70 PG genes with overlapping expression domains, recent analysis has revealed the function of several PGs in specific aspects of Arabidopsis reproductive development. Upstream regulators that control the expression domain of some of these PGs during reproductive development have also been identified. This information provides new strategies to control unwanted cell separation events in various crops.