The humidity level matters during the desiccation of Norway spruce somatic embryos.

In Norway spruce, as in many other conifers, the germination capacity of somatic embryos is strongly influenced by the desiccation phase inserted after maturation. The intensity of drying during desiccation eminently affected the formation of emblings (i.e.

The Response of Somatic Embryos to UV-B Radiation Depends on the Phase of Maturation.

Ultraviolet-B (UV-B) radiation is a key environmental signal which initiates diverse responses that affect the metabolism, development, and viability of plants. In keeping with our previous studies, we concentrated primarily on how UV-B radiation affects Norway spruce [ (L.) Karst.

Effect of drought and combined drought and heat stress on polyamine metabolism in proline-over-producing tobacco plants.

The roles of proline and polyamines (PAs) in the drought stress responses of tobacco plants were investigated by comparing the responses to drought alone and drought in combination with heat in the upper and lower leaves and roots of wild-type tobacco plants and transformants that constitutively over-express a modified gene for the proline biosynthetic enzyme Δ1-pyrroline-5-carboxylate synthetase (P5CSF129A; EC 2.7.2.

Effect of heat stress on polyamine metabolism in proline-over-producing tobacco plants.

The effect of heat stress on the accumulation of proline and on the level of polyamines (PAs) in tobacco plants was investigated. Responses to heat stress were compared in the upper and lower leaves and roots of tobacco plants that constitutively over-express a modified gene for the proline biosynthetic enzyme Δ1-pyrroline-5-carboxylate synthetase (P5CSF129A) and in the corresponding wild-type. In the initial phases of heat stress (after 2h at 40°C), the accumulation of proline increased in the wild type but slightly decreased in the transformants.

Polyamine profiles and biosynthesis in somatic embryo development and comparison of germinating somatic and zygotic embryos of Norway spruce.

The polyamine (PA) contents and activities of PA biosynthetic enzymes in Norway spruce somatic embryos [Picea abies L. (Karst.), genotype AFO 541] were studied in relation to anatomical changes during their development, from proliferation to germination, and changes in these variables associated with the germination of mature somatic and zygotic embryos were compared.

Polyamine metabolism during the cell cycle of synchronized tobacco BY-2 cell line.

The time courses of the contents of free, soluble and insoluble polyamine (PA) conjugates, PA biosynthetic and catabolic enzyme activities and mRNA levels of PA biosynthetic genes were monitored during the cell cycle of synchronized tobacco BY-2 cell line (Nicotiana tabacum L. cv. Bright Yellow 2).

Excretion of polyamines in alfalfa and tobacco suspension-cultured cells and its possible role in maintenance of intracellular polyamine contents.

Changes in polyamines (PAs) in cells and cultivation media of alfalfa (Medicago sativa L.) and tobacco bright yellow 2 (BY-2) (Nicotiana tabacum L.) cell suspension cultures were studied over their growth cycles.

Diurnal changes in polyamine content, arginine and ornithine decarboxylase, and diamine oxidase in tobacco leaves.

Changes in the contents of polyamines (PAs) in tobacco leaves (Nicotiana tabacum L. cv. Wisconsin 38) grown under 16 h photoperiod were correlated with arginine and ornithine decarboxylase (EC 4.

Polyamine metabolism during the growth cycle of tobacco BY-2 cells.

We studied polyamine (PA) biosynthesis, oxidation and conjugation in asynchronously dividing cells of tobacco BY-2 cell suspension culture (Nicotiana tabacum L.) during 7-day growth cycle. We analyzed the levels of free and conjugated PAs and the activities of biosynthetic and catabolic enzymes during the subculture interval.

Cytological changes and alterations in polyamine contents induced by cadmium in tobacco BY-2 cells.

Changes in cell viability, proliferation, cell and nuclear morphology including nuclear and DNA fragmentation induced by 0.05 and 1 mM CdSO4 (Cd2+) in tobacco BY-2 cell line (Nicotiana tabacum L.) were studied in the course of 7 days.