POSSIBILITY OF COOPERATIVE INTERACTION OF PHOTOTROPHIC AND HETEROTROPHIC TISSUES DURING CARBON-DIOXIDE PHOTOASSIMILATION

In a number of terrestrial (Halocnemum strobilaceum, Suaeda acuminata, Haloxylon aphyllum, Tradescantia fluminensis) and aquatic (Thalassode ndron ciliatum) higher plants, multicellular algae (Gracilaria verruco sa, Sargassum pallidum) and callus tissues (Ruta graveolens) containin g many heterotrophic cells in photosynthetic apparatus, photosynthetic carbon metabolism is characterised by a high level of reactions of be ta-carboxylation of phosphoenolpyruvate (PEP). The relative amount of C4-dicarbonic acids among short-term photosynthates in these objects i s higher than in typical C3-species. In comparison with C4-Plants, the part Of C4-acids is considerably smaller except of Haloxylon aphyllum and Suaeda acuminata which are also C4-species. The experiments with the callus tissue cultures of Ruta graveolens have shown that the leve l Of C4-acids among photosynthates correlates with the presence of het erotrophic tissue. The activity of PEP carboxylated enzymes in the pho totrophic callus culture of Ruta graveolens, thallus of the brown mari ne macroalga S. pallidum and leaves of the higher plant T. fluminensis is localised both in phototrophic and heterotrophic cells. A cooperat ive interaction of phototrophic and heterotrophic tissues during carbo n dioxide photoassimilation is possible.