MYB80 and TEK: Dynamic duo regulating callose wall degradation and pollen exine development

Abstract

Plant reproduction is a complex process that leads to the formation of male and female gametes in pollen and ovules, respectively. Pollen development starts with meiosis in the pollen mother cells, producing haploid pollen cell tetrads. Each tetrad is surrounded by an inner protective barrier, called the callose wall, and an outer layer made of cellulose and pectin. The callose wall, made of ß-1,3 glucan, is important for forming an outer pollen layer known as exine (Radja et al. 2019), which has two parts: the sexine (outer region) and the nexine (beneath it). The callose wall will break down later, releasing the microspores from the tetrads, which then mature further in locules. Thus, the formation and breakdown of the tetrad callose wall are critical for pollen development.