Investigations of the Role of Iron in Chlorophyll Metabolism. II. Effect of Iron Deficiency on Chlorophyll Synthesis

Abstract

The rates of incorporation into chlorophyll of C14 from various compounds was compared in leaf discs from normal and Fe-deficient cowpeas (Vigna sinensis). Severely Fe-deficient tissue incorporated C14 from [delta]-aminolevulinic acid-2-C14 into chlorophyll at rates equal to those of normal tissue. In comparably Fe-deficient tissue, the rate of incorporation into chlorophyll of C14 from a-ketoglutarate-5-C14 was about 1/20 of that of normal tissue. Moderately Fe-deficient tissue, containing about 50% of the normal content of chlorophyll incorporated into chlorophyll C14 from succinate-2,3-C14 and citrate-1, 5-C14 at rates near 50% of those of normal tissues. It was concluded that Fe deficiency reduced the rate of synthesis of [delta]-aminolevulinic acid and that the decreased synthesis of the compound may be sufficient to account for the low chlorophyll content of Fe-deficient plants.