The DOXP/MEP pathway, also known as the non-mevalonate pathway, plays an essential role in creating the chemicals needed for many plants to function. This pathway, combined with the MEP/DOXP pathway give many plants their scents, such as cinnamon and ginger, and are responsible for the red colour in tomatoes. Terpenoids, also called isoprenoids, are a substantial yet varied class of organic chemicals that occur naturally. Plant terpenoids have aromatic qualities and are used for this and their role in traditional herbal remedies. The pathway begins with D-glyceraldehyde 3-phosphate, which is produced through glycolysis. Together with pyruvic acid and the enzyme 1-deoxy-D-xylulose 5-phosphate synthase 1, these are catalyzed into 1-deoxy-xylulose 5-phosphate. From there, 1-deoxy-xylulose 5-phosphate teams up with 1-deoxy-D-xylulose 5-phosphate reductoisomerase to create 2-c-methyl-D-erythritol 4-phosphate. Moving along in the chloroplast, after being produced through 2-c-methyl-D-erythritol 4-phosphate and the enzyme 2-c-methyl-D-erythritol 4-phosphate cytidyltransferase,4-cytidine 5'-diphospho)-2-C-methyl-D-erythritol is catalyzed by 4-diphosphocytidyl-2-c-methyl-D-erythritol kinase to create 2-phospho-4-(cytidine 5'-diphospho)-2-c-methyl-D-erythritol. After that, 2-c-methyl-D-erythritol 2,4-cyclodiphosphate synthase uses the newly produced 2-phospho-4-(cytidine 5'-diphospho)-2-c-methyl-D-erythritol to create 2-c-methyl-D-erythritol-2,4-cyclodiphosphate. This compound is then joined with 4-hydroxy-3-methylbut-2-en-1-yl diphosphate synthase to become 1-hydroxy-2-methyl-2-butenyl 4-diphosphate. This compound gets busy soon after its inception, branching off into two separate reactions: first reacting with 4-hydroxy-3-methylbut-2-enyl diphosphate reductase to create isopentenyl pyrophosphate, then reacting with the same enzyme to create dimethylallylpyrophosphate. Dimethylallylpyrophosphate is then looped into another reaction with isopentenyl-diphosphate delta-isomerase II, recreating isopentenyl pyrophosphate. It also reacts with geranylgeranyl pyrophosphate synthase 6, bringing the pathway into the mitochondrion to create geranyl pyrophosphate. This is later followed by a monoterpenoid biosynthesis pathway.

MEP/DOXP Pathway References