CALS1 (CALLOSE SYNTHASE 1); 1,3-beta-glucan synthase/ transferase, transferring glycosyl groups; Encodes a callose synthase 1 catalytic subunit . Member of Glycosyltransferase Family- 48. ; Involved in callose synthesis at the forming cell plate during cytokinesis. Not required for callose formation after wounding or pathogen attack. During plant growth and development, callose is found as a transitory component of the cell plate in dividing cells, is a major component of pollen mother cell walls and pollen tubes, and is found as a structural component of plasmodesmatal canals (1950 aa)