Proposed scheme of β-carotene biosynthesis in D. bardawil. Two pathways for β-carotene biosynthesis in D. bardawil are a constitutive pathway in the chloroplast (green) and an inducible pathway in the βC-plastoglobuli (orange). DMPP, Dimethylallyl diphosphate; GA3P, glyceraldehyde 3-phosphate; GGPP, geranylgeranyl diphosphate; GPP, geranyl pyrophosphate; IPP, isopentenyl diphosphate; ZDH, ζ-carotene dehydrogenase.