Polygalacturonase required for cell type-specific pectin degradation to separate microspores. Involved in anther dehiscence and floral organ abscission. (1,4-alpha-D-galacturonosyl)n+m + H2O = (1,4-alpha-D-galacturonosyl)n + (1,4-alpha-D-galacturonosyl)m. Expressed predominantly in roots with lower expression levels in rosette leaves, flower buds and siliques. Bearly detected in seeds. Found in flowers undergoing floral organ abscission. Also expressed early in anther development, at the time of microspore separation. The mature pollen grains are arranged in a tetrad. No visible phenotype regarding floral organ abscission. Belongs to the glycosyl hydrolase 28 family.