Figure 3. Cuticular wax biosynthetic pathway related genes inPse. libanotica under drought stress Cuticular wax are synthesized and secreted in the endoplasmic reticulum (ER). First, long-chain fatty acids (C16–C18) are synthesized in the plastids. Second, the saturated C16 and C18 fatty acyl-CoA precursors are elongated to very long chain fatty acyl-coenzyme As (VLCFA-CoAs) in ER. Once the VLC-acyl-CoAs are synthesized, they can be further released as free VLCFAs that can either be directly exported as cuticular waxes, or undergo further modifications in the via either the alkane-forming pathway or the alcohol-forming pathway.