BSA Plant Images Online - Left, plugs of callose, penetrated by plasmodesmata, fill the pores. Right, pores open, lined with thin layer of callose, and most are occluded with P-protein, some with starch grains. (Echium wildpreti petioles)
Left, plugs of callose, penetrated by plasmodesmata, fill the pores. Right, pores open, lined with thin layer of callose, and most are occluded with P-protein, some with starch grains. (Echium wildpreti petioles)