title: The regulation of ascorbate biosynthesis.
abstract: We review the regulation of ascorbate (vitamin C) biosynthesis, focusing on the l-galactose pathway. We discuss the regulation of ascorbate biosynthesis at the level of gene transcription (both repression and enhancement) and translation (feedback inhibition of translation by ascorbate concentration) and discuss the eight proteins that have been demonstrated to date to affect ascorbate concentration in plant tissues. GDP-galactose phosphorylase (GGP) and GDP-mannose epimerase are critical steps that regulate ascorbate biosynthesis. These and other biosynthetic genes are controlled at the transcriptional level, while GGP is also controlled at the translational level. Ascorbate feedback on enzyme activity has not been observed unequivocally.
authors.affiliation: The New Zealand Institute for Plant & Food Research Limited, 412 No 1 Road, RD 2, Te Puke 3182, New Zealand.
authors.forename: Sean
authors.initials: S
authors.lastname: Bulley
authors.affiliation: The New Zealand Institute for Plant & Food Research Limited, Food Industry Science Centre, Batchelar Road, Palmerston North 4474, New Zealand. Electronic address: William.laing@plantandfood.co.nz.
authors.forename: William
authors.initials: W
authors.lastname: Laing
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D001205:Ascorbic Acid / Q000096:biosynthesis*; D005690:Galactose / Q000378:metabolism*; D014176:Protein Biosynthesis; D014158:Transcription, Genetic
chemical_list: D001205:Ascorbic Acid; D005690:Galactose