1998 , Sirikantaramas et al. 2004 , Fig.3.5). ForCannabisterpenoid biosynthesis,
the plastidial methylerythritol phosphate (MEP) pathway, is mainly responsible
(Sirikantaramas et al. 2007 ). Thefirst step in the cannabinoids biosynthetic pathway
is the formation of Olivetolic acid. Olivetolic acid (OLA) and geranyl diphosphate
(GPP) are derived from the polyketide and the deoxyxylulose phosphate (DOXP)/
MEP pathways, respectively. By the action of prenylase, geranyl diphosphate:
olivetolate geranyltransferase (GOT), cannabigerolic acid (CBGA) is obtained,
which further is oxido-cyclized by Flavin Adenine Dinucleotide (FAD)-dependent
oxidases, namely, cannabichromenic acid (CBCA) synthase, cannabidiolic acid
(CBDA) synthase andD^9 -tetrahydrocannabinolic acid (D^9 -THCA) synthase, pro-
ducing CBCA, CBDA andD^9 -THCA, respectively (Flores-Sanchez and Verpoorte
2008 ). Detailed biosynthesis of plant cannabinoids are described in Chap. 8.
3.3 CannabisHorticulture
Cannabis sativaL. is an annual plant that can be grown‘indoor’and‘outdoor’
efficiently. However, each cultivation option has its advantages and disadvantages.
Under the outdoor conditions, life cycle of the plant completes infive to seven
months depending on the time of plantation and the variety whereas, growing
indoor,flowering can be triggered by regulating the photoperiod. Outdoor culti-
vation is affected by factors as wind and rain that can destroyCannabisplants.
Δ9
-THCCBDOOHC 5 H 11OHC 5 H 11
OH(a)(b)Fig. 3.4 Chemical structures
of two major
phytocannabinoids present in
Cannabis sativa,aD^9 -
Tetrahydrocannabinol (D^9 -
THC) andbCannabidiol
(CBD)
3 Cannabis sativaL.: Botany and Horticulture 85