Relationship between the morphological structure of floral nectaries and the formation, transport, and secretion of nectar in lychee

Abstract

Key message The sugar in nectar secreted from the floral nectaries of lychee (Litchi chinensisSonn.) was composed of both the phloem sap and the starch synthesized by the nectariferous tissue itself. Sugar hydrolyzed from the starch and from the phloem might be transported to the endoplasmic reticulum (ER) and the Golgi cisternae, further transported via ER and Golgi vesicles, and eventually released to the spaces between the plasmalemma and cell wall by exocytosis. There was a specific sugar transport and secretory mechanism in the lychee floral nectary.