2.1.1.13	5-methyltetrahydrofolate + L-homocysteine	methionine biosynthesis	
2.1.1.13	5-methyltetrahydrofolate + L-homocysteine	gene expression is induced by light, but more strongly induced under salt, drought and cold stresses and by treatment with ABA or H2O2	
2.1.1.13	5-methyltetrahydrofolate + L-homocysteine	homocysteine increases methionine synthase mRNA level	
2.1.1.13	N5-methyltetrahydrofolate + L-homocysteine	transcription is not regulated by Met, but is enhanced by homocysteine and repressed by choline and betaine. Synthesis of the enzyme is also regulated posttranscriptionally