TRANSFER CELLS IN THE VASCULAR PARENCHYMA OF ROOTS

Structural adaptations to increased transport activities were investigated in the cells of vascular parenchyma at the site of the lateral root junction, in non-stressed plant roots. Typical transfer cells were differentiated in dicotyledonous Helianthus tuberosus and in two different genotypes of H. annuus, the cv. IBH166 and a decorative form. In the representatives of monocotyledonous, no structural adaptations occurred in the roots of Hordeum vulgare but small and rare cell wall protuberances were found in xylem and phloem of Zea mays inbred line VIR17. Some degree of cell wall labyrinth differentiation was seen in xylem and typical transfer cells were found in phloem of the roots of the maize hybrid CE380. The capability of vascular parenchyma to differentiate transfer cells did not depend on species, genotype, or on the growing conditions with Helianthus. On the other hand, the development of the structural adaptations in monocotyledonous representatives depended on both the species and the genotype. This capability may be linked with the taxonomic and evolutionary position of plant species