Crystalloid formation in protochlorophyll-accumulating plastids from the inner seed coat of Cyclanthera explodens

The development of fruit, seed and plastids in the inner seed coat of Cyclanthera explodens Naud. was studied. Large amounts of protochlorophyll, in at least three different in vivo-forms, accumulated during maturation and was 14 mg/g fresh weight of the inner seed coat in mature seeds. In earlier stages plastid-membrane-lipids increased simultaneously with the pigment. This could also be seen in electron micrographs as an increased amount of membranes. During later stages the amount of pigment continued to increase without an increase in the lipids. At this stage large crystalloids were found in the plastids. The data presented led to the conclusion that the protochlorophyll form fluorescing at 691 nm is crystalline.