for the formation of sulfur-containing amino acids and peptides (primary route) and for the
modification of diverse metabolites (secondary route). In plants, the fate of assimilated
sulfate depends on the three enzymes–ATP sulfurylase, adenosine-5′-phosphate (APS)
reductase, and APS kinase-that form a branchpoint in the pathway. ATP sulfurylase
catalyzes the formation of the critical intermediate APS, which can either be used in the …