Yuri V. Gamalei

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To determine the driving forces for symplastic sugar flux between mesophyll and phloem, gradients of sugar concentrations and osmotic pressure were studied in leaf tissues of two Scrophulariaceae species, Alonsoa meridionalis and Asarina barclaiana. A. meridionalis has a typical symplastic configuration of minor-vein phloem, i.e. intermediary companion(More)
Minor vein structure in various taxonomic groups was described in a previous paper (Gamalei 1989). Here, these results are used to correlate minor vein structure with plant evolutionary, ecological and growth form schemes. The following pattern emerges: reductive evolution from evergreen trees to annual herbs is accompanied by gradually increasing(More)
Two modes of phloem loading have been proposed, apoplastic and symplastic, depending on the structure of sieve element-companion cell complexes (SE-CCCs) in minor vein phloem. Species are usually classified as either apoplastic or symplastic loaders although the cytology of SE-CCCs in minor veins of the majority of plants indicates that both mechanisms can(More)
Plant species were selected on the basis of abundant or no symplasmic continuity between sieveelement-companion-cell (SE-CC) complexes and adjacent cells in the minor veins. Symplasmic continuity and discontinuity are denoted, respectively, as symplasmic and apoplasmic minor-vein configurations. Discs of predarkened leaves from which the lower epidermis had(More)
The phloem-loading-related effects of temperature on leaf ultrastructure were studied in seven species having numerous plasmodesmatal connections between the mesophyll and phloem (symplasmic minor-vein configuration). The response to temperature (between 5 and 30 °C) was characterized by drastic changes in the endoplasmic-reticulum labyrinth (ER labyrinth)(More)
Datisca glomerata forms nitrogen-fixing root nodules in symbiosis with soil actinomycetes from the genus Frankia. Analysis of sugars in roots, nodules and leaves of D. glomerata revealed the presence of two novel compounds that were identified as α-l-rhamnopyranoside-(1 → 6)-d-glucose (rutinose) and α-l-rhamnopyranoside-(1 → 6)-1-O-β-d-methylglucose(More)
In mesophyll cells of species with a symplasmic (Ocimum basilicum, Catharanthus roseus, Magnolia denudata) or an apoplasmic (Vicia faba, Impatiens walleriana, Bellis perennis) minor-vein configuration, membrane depolarizations in response to 20 or 200 mol·m−3 raffinose and sucrose were measured. Ageing period and resting potential marginally affected the(More)
The discovery of abundant plasmodesmata at the bundle sheath/phloem interface in Oleaceae (Gamalei, 1974) and Cucurbitaceae (Turgeon et al., 1975) raised the questions as to whether these plasmodesmata are functional in phloem loading and how widespread symplasmic loading would be. Analysis of over 800 dicot species allowed the definition of "open" and(More)
In this communication, direction of evolutionary variability of parameters of genome size and structurally functional activity of plants in angiosperm taxa among life forms, are analyzed. It is shown that, in the Cretaceous–Cenozoic era, the nuclear genome of the plants tended to increase. Functional genome efficiency (intensity of functions per pg of DNA)(More)