Peculiarities of uidA Gene Expression under the Control of AP3 and RPT2a Tissue-Specific Gene Promotors of Arabidopsis thaliana L. in Nicotiana tabacum L. Transgenic Plants

The features of the expression of the uidA reporter gene, encoding the β-glucuronidase enzyme, under the control of AP3 and RPT2a tissue-specific gene promoters of Arabidopsis thaliana L. was studied in homozygous monoinserted transgenic plants of Nicotiana tabacum L. Both promoters ensured the expression of the reporter gene in the meristematic tissues of tobacco plants, although the type of expression shown for the AP3 promoter was ectopic. In analyzed groups of transgenic plants and their hybrids wide variability in mRNA accumulation and in β-glucuronidase activity was observed. It was shown that the level of accumulation of the uidA reporter gene transcript does not correlate with the level of enzymatic activity of its product. The variability among the analyzed transgenic tobacco plants is most likely associated with the peculiarities of chromatin organization in the regions of T-DNA insertions and/or is caused by the different nature of interactions between the cis-elements of the studied promoters and plant regulatory elements located outside the region of the T-DNA insertion. According to the results of bioinformatic analysis, approximately 20 cis-regulatory elements were identified in the structure of the investigated promoters, some of which were found in both promoters. In general, the results of the analysis showed that the AP3 and RPT2a gene promoters of A. thaliana can be effective as regulatory elements for the expression of transgenes in the meristematic tissues of other plant species, in particular, N. tabacum .