Pectinesterase required for cell type-specific pectin degradation to separate microspores. [(1->4)-alpha-D-galacturonosyl methyl ester](n) + n H2O = [(1->4)-alpha-D-galacturonosyl](n) + n H(+) + n methanol Glycan metabolism; pectin degradation; 2-dehydro-3-deoxy-D-gluconate from pectin: step 1/5. Expressed in flower buds, siliques, developing guard cells, floral nectares, at the stigmatic surface, in the hypocotyl-root transition zone and the area of lateral root emergence. Not expressed in mature leaves. Expressed in anther tissues shortly after meiosis is completed and during the late developmental phases of siliques. The mature pollen grains are arranged in a tetrad. Belongs to the pectinesterase family.