Vliv transformace genem cdc25 ze Schizosaccharomyces pombe na morfogenezi rostlin Nicotiana tabacum L., cv. Samsun

Abstract

Morphogenetic processes including process of de novo organ formation is governed by the rate, frequency and orientation of cell division. Cell cycle is a complex process with complicated regulation. CDKs (cyclin-dependent kinases) are taken for the key proteins regulating cell cycle progression. These proteins are well conserved among eucaryotic organisms. CDK activity strictly depends on specific subunit - cyclin. The activity of the CDK-cyclin complex can be further modified besides others by phosphorylation/dephosphorylation. In yeast (and in most eukaryotic organisms) activating defosforalation of CDKs is performed by Cdc25 phosphatase. Situation in plants is still not fully elucidated. A small CDC25-like tyrosine-phosphatase was recently identified in Arabidopsis thaliana (Arath;CDC25), which could not, however, complement the temperature sensitive Spcdc25-22 mutant (Landrieu et al., 2004). This study is focused on the effect of expression of the foreign gene (S. pombe) coding for Cdc25 phosphatase on the morphogenesis, especially on the ability of de novo organ formation, in tobacco. Plant material used for experiments: Nicotiana tabacum L., cv. Samsun, wild type, two independent lines transformed with Spcdc25 under a constitutive promotor (designated as lines A and C) (Bell et al., 1993) and...