Identification of the Elusive Chloroplast Ascorbate Transporter Extends the Substrate Specificity of the PHT Family

摘要

Most of the enzymatic reactions of ascorbate biosynthesis occur in the cytosol,with the exception of the terminal step,catalyzed by L-galactono-1,4-lactone dehydrogenase,which is localized on the inner mitochondrial membrane.Given the location of L-galactono-1,4-lactone dehydrogenase,the rate of ascorbate biosynthesis is intimately associated with the rate of mitochondrial respiration (Nunes-Nesi et al.,2005).