Ascorbic acid biosynthesis pathway

The **ascorbic acid biosynthesis pathway** refers to the series of enzymatic reactions responsible for the cellular production of **L-ascorbic acid** (vitamin C) in plants and some other organisms. In higher plants, the predominant route is called the **L-galactose pathway** or **Smirnoff–Wheeler pathway**, involving at least eight characterized enzymes that catalyze the transformation of glucose-derived intermediates into ascorbate. The pathway is vital for maintaining cellular redox balance, serving as both a primary antioxidant and a cofactor in several physiologic processes; it also plays a prominent role in stress response, growth, photosynthesis, and electron transport. In humans and some animals, the pathway is incomplete due to a loss-of-function mutation in the terminal enzyme, rendering them reliant on dietary intake of vitamin C[1][3][4]. While enzymes of this pathway (such as GDP-mannose pyrophosphorylase, L-galactono-1,4-lactone dehydrogenase, etc.) can be considered molecular targets for genetic and agronomic intervention to boost vitamin C content in crops, the **pathway itself is not a discrete molecular target** but rather a metabolic route comprised of several individual, targetable enzymes[1][4][5][6]. **Note**: This entry is considered *incorrect* in the context of a target database because it does not designate a single molecular entity (receptor, enzyme, transporter, etc.), but instead refers to a **metabolic pathway**. For appropriate database usage, each individual enzyme involved (e.g., GDP-mannose pyrophosphorylase, L-galactono-1,4-lactone dehydrogenase) should be listed as targets, not the entire pathway[1][3][4].

Other names

Vitamin C biosynthesis pathwayL-ascorbic acid biosynthesis pathwaySmirnoff-Wheeler pathway (for plants)