Ultrastructure of the Resin Ducts of Mangifera indica L. (Anacardiaceae). 2. Resin Secretion in the Primary Stem Ducts

The resin of the mango stem consists mainly of terpenes. The terpenes seem to be produced primarily by plastids, termed here secretoplasts. At the beginning of the process of secretion, osmiophilic droplets are seen at the envelope of the secretoplasts and at elemints of periplastidal ER. In addition, such droplets occur also at Golgi bodies and occasionally in association with mitochondria. Later osmiophilic material fills the well-developbd ER, which at this stage is mainly tubular. It appears that the ER is involved in the transport of the sareted material towards the plasmalemma.