Practice question

Callose envelope of β-1,3-glucan surrounding pollen mother cells and tetrads must be rapidly degraded to liberate free microspores for pollen wall development. Enzyme responsible callase β-1,3-glucanase is actively synthesized and precisely secreted by tapetum layer of anther wall under transcriptional regulation of AMS, MS1, TDF1, and MYB80 factors. Secreted callase hydrolyzes callose allowing microspore expansion, primexine formation, and sporopollenin deposition forming characteristic exine pattern. Disruption of tapetal secretion causes tetrad persistence and complete male sterility, highlighting exquisite tissue coordination required for pollen release and fertility assurance.