The Widespread Occurrence of Polyphosphate in Lower Plants

Abstract

The widespread occurrence of polyphosphate (PoP) in lower plants is described. PoP granules have been cytochemically detected in algae, slime moulds, and mosses. A systematic survey is given of lower plants in which the occurrence of PoP has been demonstrated with both the present studies and previous investigations. The localization of PoP in cells has been studied. PoP granules have been observed to be present in the cytoplasm, the cytoplasmic vacuole, and in chloro-plasts of different algae. In Zygnemataceae and in mosses PoP granules are localized in the chloroplasts which also contain pentose nucleic acid. A relationship between PoP, pentose nucleic acid (PNA), and growth has been found and is discussed. A possible in situ synthesis of PoP in chloroplasts from phosphorylated intermediates of the photosynthetic process is suggested.