Radioisotopic Study of Cholorophyll Accumulation in Soybean Leaves, in the Conditions of a Transfer from one Daylength to another ("Transfer-Effect")

The transfer of Soybean plants from one daylength to another greatly affects the accumulation of the chlorophylls in the leaves. This "transfer-effect" is studied using C14 Δ-aminolevulinic acid as tracer. It is shown that the relative labeling of the two forms of chlorophyll (a and b) varies according to the daylength treatment. A tentative interpretation of the facts is proposed. It is based on the assumption that in certain conditions, some molecules of chlorophyll b could be produced as a result of the photoxidation of some molecules of chlorophyll a.