DNA recombinant technology was a landmark for the development of the
synthetic biology, which constitutes an intersection area between biology
and engineering and should contribute to designing biological systems.The
development of effective tools,which allow us to increase precision on gene
regulation are essential for proper genetic manipulation. Current
information has demonstrated effective control of the RNA polymerase flux
using different integrases, capable to catalyse unidirectional inversion of
DNA to turn on/off regulatory genes in prokaryotic cells.However, knowledge
about the functionality of integrases in eukaryotic cells isstill limited.
Here we show the remarkable functional capability ofbacteriophages serine
integrasesin plant cells.A co-transformation plasmid system was utilized to
evaluate integrases in *A. thaliana* protoplasts. The first plasmid
contained the codon optimized integrase 2 gene or the integrase 5 gene
sequences under inducible promoters. The second plasmid was the reporter
plasmid that contains the *gfp* gene under the 35SCaMV promoter placed in
reverse complement orientation and flanked by the attB and attP sites of
both integrases.Once the integrases were expressed, it would flip the
promoter sequence toits correct orientation and promotingGFP expression.The
results proved that the promoter was flipped leading to the RNA polymerase
flux through the DNA molecule and the GFP expression, which was detected by
fluorescent microscopy.The promoter inversion was detected by PCR and
sequencing analyses. We anticipate our results to be an initial point for
development of more complex models of gene regulation in plants using
integrases.