Structures of Phosphoenolpyruvate carboxylase (PEPC) Gene Promoter from C4 and C3 Flaveria species Using Sequence Analysis by Bioinformatics Tools

Aim: This research can be used to design and subsequently to study stable- tissues- specific gene expression in other plants, and potentially may be used in altering plants with C3 photosystem into C4 through genetics.
Study design: In silico analysis by bioinformatics tools was used to analyze the promoter regions of Phosphoenolpyruvate carboxylase (PEPC) genes in genus Flaveria (Asteraceae).
Methodology: Detailed promoter gene studies of the C3 and C4 ppcA1 genes in Flaveria sp. have been deposited by EMBL/GenBank data. To find regulatory elements in promoter sequences, PLANTCARE and PLACE database were applied. Moreover, ClustalW2 & MAFFT were used for multiple sequence alignment.
Results: The results revealed that light-inducible promoters of PEPC genes in Flaveria species have cis-elements for organ- and cell-specific expression, which may be subdivided into six classes: 1) Elicitor specific, 2) Component specific (hormone-responsive elements), 3) Light responsiveness, 4) Binding site specific, 5) Condition specific (stress-responsive elements) and 6) Plant tissues specific.
Conclusion: The distal region (DR) of promoter behaves as an enhancer-like expression module and is able to confer a mesophyll expression while the proximal region (PR) is responsible for a quantitative expression. Coordinated motifs indicate that the response of pepc gene is controlled by light in coordination with hormones and stresses and potentially may be used in altering plants with C3 photosystem into C4 through genetics.