The formation of delta‐Aminolevulinate a precursor of chlorophyll, in barley and the role of iron

Abstract

Chlorophyll formation in higher plants is light dependent. Light directly affects the formation of 6‐aminolevulinic acid (ALA) and the conversion of protochlorophyll to chlorophyll. Various chelators that form especially stable compounds with ferrous iron reduce the formation of ALA in etiolated barley leaves. Barley grown under iron stress has little capacity to form ALA unless supplemental iron is added. Chelated iron and FeSO₄ are much more effective in restoring ALA formation than FeCl₃. Added organic compounds (citrate, α‐ketoglutarate and glucose) also stimulated ALA synthesis. The role of iron in ALA and chlorophyll synthesis is discussed.