GLANDULAR CUTICLE FORMATION IN CANNABIS (CANNABACEAE)

Abstract

Formation of the cuticle from components of the secretory cavity and subcuticular wall was studied by transmission electron microscopy of glandular trichomes of Cannabis prepared by high pressure cryofixation-cryosubstitution. Secretory vesicles in the secretory cavity resembled those localized in the subcuticular wall as well as the vesicle-related material associated with the irregular inner surface of the cuticle and appeared to provide precursors for thickening of the cuticle. Some contiguous vesicles in the secretory cavity and subcuticular wall lacked a surface feature at their point of contact, supporting an interpretation of vesicle fusion. Fibrillar matrix from the secretory cavity contributed fibrillar matrix to the subcuticular wall, and persisted as residual fibrillar matrix associated with secretory materials coalesced to the thickened inner surface of the cuticle. Elongated fibrils arranged in uniformly spaced parallel pairs contributed to the organization of fibrillar matrix in the subcuticular wall. Striae were evident in the outer portion of the cuticle, and appeared to represent sites of degraded residual fibrillar matrix associated with secretory materials coalesced to the inner cuticular surface. This study supports an interpretation that contents of secretory vesicles from the secretory cavity contribute to formation of glandular cuticle.

Secretory Structures of Pogostemon auricularius: Morphology, Development, and Histochemistry

“…It was suggested that new cutin was added to the expanding cuticle of glandular trichomes in Peppermint [27] and Origanum [28]. In young peltate glandular trichomes of P. auricularius, the vesicle-like structures outside the cell wall indicated the possible role of these structures in the formation of cuticle, as proposed by Kim and Mahlberg [42]. The thickness of the cuticle was uniform in the early secretory stage.…”

Evolution and Classification of Cannabis sativa (Marijuana, Hemp) in Relation to Human Utilization

“…Mahlberg and Kim (2004) observed that the cannabinoid content of the long-stalked glands that they examined possessed about 20 times the cannabinoid content of sessile glands (which are usually much smaller than the former). The glands of Cannabis have been extensively examined by Mahlberg and associates (Hammond & Mahlberg, 1977, 1978Kim & Mahlberg, 1995, 1997Mahlberg & Kim, 1991, 1992Mahlberg et al, 1984;Turner et al, 1980Turner et al, , 1981a. It has been established that cannabinoids are synthesized within the secretory glands, not elsewhere and transported to the glands (Sirikantaramas et al, 2005;Stout et al, 2012).…”