The contents of auxin (indole-3-acetic acid, IAA), cytokinins, and abscisic acid (ABA) were determined in explants (megagametophyte embryo), proliferating embryonal-suspensor mass (ESM), non-embryogenic callus Pinus sibirica Larix sibirica. Furthermore, the localization hormones cells was studied with immunohistochemical analysis. It shown that formation embryogenic cultures both species is ass...

In Cichorium hybrid clone '474' (C. intybus L., var. sativum x C. endivia L., var. latifolia), the direct somatic embryogenesis process in leaf tissues is accompanied by an overall increase in the amount of proteins secreted into the culture medium. Amongst these, three major protein bands of 38 kDa, 32 kDa and 25 kDa were found in the conditioned media. These extracellular protein bands accumu...

Culturing leaf protoplast-derived cells of the embryogenic alfalfa (Medicago sativa subsp. varia A2) genotype in the presence of low (1 microM) or high (10 microM) 2, 4-dichlorophenoxyacetic acid (2,4-D) concentrations results in different cell types. Cells exposed to high 2,4-D concentration remain small with dense cytoplasm and can develop into proembryogenic cell clusters, whereas protoplast...

Embryogenic cultured cells of Daucus carota have been shown to synthesize putrescine from exogenously supplied [(14)C]arginine at twice the rate of control nonembryogenic cells. In the present paper, the activity of arginine decarboxylase (arginine carboxy-lyase, EC 4.1.1.19), an important enzyme in the synthesis of putrescine, was assayed and also found to be elevated by as much as 2-fold in e...

Under specific stress treatments (cold, starvation), in vitro microspores can be induced to deviate from their gametophytic development and switch to embryogenesis, forming haploid embryos and homozygous breeding lines in a short period of time. The inductive stress produces reactive oxygen species (ROS) and nitric oxide (NO), signalling molecules mediating cellular responses, and cell death, m...

Embryogenic tissue culture systems are utilized in propagation and genetic engineering of crop plants, but applications are limited by genotype-dependent culture response. To date, few genes necessary for embryogenic callus formation have been identified or characterized. The goal of this research was to enhance our understanding of gene expression during maize embryogenic tissue culture initia...

Feasible and efficient tissue culture plays an important role in plant genetic engineering. Wheat (Triticum aestivum L.) immature embryos (IMEs) are preferred for tissue culture to mature embryos (MEs) because IMEs easily generate embryogenic callus, producing large number of plants. The molecular mechanisms of regulation and the biological pathways involved in embryogenic callus formation in w...

Brassica napus cultivar Westar is non-embryogenic under all standard protocols for induction of microspore embryogenesis; however, the rare embryos produced in Westar microspore cultures, induced with added brassinosteroids, were found to develop into heritably stable embryogenic lines after chromosome doubling. One of the Westar-derived doubled haploid (DH) lines, DH-2, produced up to 30% the ...

Frequency of somaclonal variation in embryogenic calli and plants of Olea europaea L cv.Kroneiki derived from somatic embryogenesis were examined by randomly amplified polymorphic DNA (RAPD) analysis. Radicle and cotyledon (proximal part) of mature zygotic embryo were cultured in OMc medium supplemented with IBA (5 mgL-1) and 2-ip (0.5 mgL-1). Somatic embryogenesis was induced in calli of radic...