Expression of four genes involved in the d-Man/l-Gal pathway for ascorbate biosynthesis in Lotus. The steady-state mRNA levels of GMP, GME, GalDH, and GalLDH were quantified in leaves, roots, and nodules by qRT-PCR. Values of leaves (L) and nodules (N) were expressed relative to roots of the same plants (which were arbitrarily given a value of 1) and are means ± se of four to five different extracts from at least two series of plants grown independently.