Helianthus annuus Embryogenesis: Embryo Sac Wall Projections Before and After Fertilization

Massive wall ingiowths occur in the micropylar end of the embryo sac of sunflower Helianthus annuus L These projections arise after the deposition of the common wall separating the two synergids, apparently as a result of Golgi activity After fertilization, endosperm cell wall is laid down over the embryo sac wall projections suggesting an altered pathway for solutes into the embryo sac The possible nutritional significance of these projections is discussed