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CO2-fixierung und stofftransport in benthischen marinen algen. II. zum ferntransport 14C-markierter assimilate bei laminaria hyperborea und laminaria saccharina

1972; Elsevier BV; Volume: 67; Issue: 5 Linguagem: Inglês

10.1016/s0044-328x(72)80042-4

0044-328X

Klaus Schmitz‐Abe, Klaus Lüning, Johannes Willenbrink,

Marine and coastal plant biology

Transport of 14C-labelled assimilates was studied during the main growth period of two Laminaria species. H14CO3- was fed to the plants using a plexiglas chamber tightly fixed to the phylloid 40–50 cm from the growing region. The phylloids were harvested after 3–96 hours and cut into segments 15 mm in length. Radioactivity was determined by dry combustion and subsequent liquid scintillation counting. Labelled sugars, amino acids and organic acids were analysed after extraction with 80 % and 50 % ethanol by chromatography. The pathway of translocation was studied by histoautoradiography. Nearly all of the labelled translocate moved towards the base of the phylloid, and significant accumulation of translocate occurred within the growing region of the phylloid and in growing haptera. The labelled translocate consisted of mannitol (53 %), amino acids (alanine, glycine, serine, glutamic acid and some others; 45 %) and malate (2 %). This composition is similar to that of the products of photosynthesis in L. saccharina. In most experiments the translocation velocity was about 5 cm/h, and the maximum velocity did not exceed 10 cm/h. Certain groups of cells within the medulla of the phylloid were identified as the conducting tissue.