Figure 3.

Methionine (Met) salvage cycle and ethylene, nicotianamine (NA), phtosiderophore (PS), and polyamine (PA) synthesis associated with proteins that are differentially accumulated upon Fe deficiency. As a central metabolite, SAM (S-adenosyl-methionine) is synthesized by SAMS (S-adenosylmethionine synthetase) from Met. Followed, SAM can be converted to MTA (methylthioadenosine) and ACC (aminocyclopropane-1-carboxylate) that is further converted to ethylene. SAM is also a precursor of PA and NA, which is converted to PS in Strategy II plant species. KMTB, 2-keto-4-methylthiobutyrate; MTR-P, methylthioribose phosphate; ARD, acireductone dioxygenase; ACS, ACC synthase; MTK, 5-methylthioribose kinase; DEP1, EHYDRATASE-ENOLASE-PHOSPHATASE-COMPLEX1; ACO, ACC oxidase.