Figure 1. Overview of the reported regulators on L-galactose pathway of AsA synthesis. The broken line box shows L-galactose pathway. Enzymes: (1) GDP-Man pyrophosphorylase (VTC1);(2) GDP-Man-3′,5′-epimerase (GME);(3) GDP-L-Gal phosphorylase (VTC2/VTC5); (4) L-Gal 1-phosphate phosphatase (GPP);(5) L-Gal dehydrogenase (GalDH); (6) L-GalL dehydrogenase (GalLDH). Salt stress triggers ERF98 expression and subsequently VTC1 higher expression on transcriptional level, finally improving AsA content to respond stress, but the modulation of ERF98 on other enzymes needs further research. Light inhibits AMR1 expression, which further deactivates the expression of the synthesis enzyme genes mediated by an unknown protein. When the light goes out, CSN5B carry out function to inhibit AsA synthesis on post-transcriptional level through interaction with VTC1 directly to promote its degradation.