Summary Four multiple forms (enzymes A, B, C and D) of starch phosphorylase (EG 2.4.1.1) in plant leaves were detected by polyacrylamide gel electrophoresis with the following electrophoretic mobilities (cm/2 1/2 h) in the respective order: 1.9, 2.2, 3–2 and 4.2. In Marigold leaves, one starch phosphorylase, enzyme B, was present throughout the maturation stage and was localized in the soluble fraction. Cabbage leaves, contained four multiple forms of the enzyme (enzymes A, B, C and D) in young leaves which decreased to one (enzyme C) in the mature leaves. In cabbage, the enzyme detected in mature leaves (enzyme C) was in the soluble fraction whereas, in the young leaves three of the four (enzymes A, B and D) were partially localized in the chloro-plast and partially in the soluble fraction. Potato leaves contained three starch phosphorylases (enzymes B, C and D), one (enzyme B) was partially localized in the chloroplast and partially in the soluble fraction while the other two (enzymes C and D) were in the soluble fraction throughout maturation. Two enzymes (enzymes B and C) were present in the brinjal leaves, one (enzyme B) was partially localized in the chloroplast and partially in the soluble fraction while the other (enzyme C) was totally in the soluble fraction. Arhar leaves contained two enzymes (enzymes C and D) throughout maturation, one (enzyme C) was partially localized in the soluble fraction and the other (enzyme D) was entirely in the soluble fraction. Turnip leaves had one enzyme (enzyme B) which was localized in the soluble fraction throughout maturation.
