Gene expression analysis associated with tissue-specific promoters in Musa spp.

ABSTRACT. The study of promoters has become essential to elucidate genetic regulation and allow new genetic transformation strategies through plant biotechnology. The challenge is to discover and validate promoters that can regulate gene transcription spatially and/or temporally. The goal of this work was to validate genes associated with tissue-specific promoters of bananas obtained from in silico sequences and selected from the DATAMusa databank. Gene expression was quantified using RT-qPCR from different tissues: leaves, flowers, roots, unripe pulp, ripe pulp, unripe peels, and ripe peels of two different genetic groups: Prata-Anã (PA; group AAB) and Grand Naine (GN; group AAA). After the analysis of the expression of genes associated with the promoters, normalization was performed with the most stable reference genes (TUB and L2) selected using the RefFinder tool. It was determined that five genes were specific or expressed to a greater extent in some tissues than others. The EMB-23 gene was highly expressed in ripe pulp and flowers of GN, EMB-26 in the ripe pulp of GN, EMB-27 in flowers of GN, EMB-28 in roots of PA and ripe pulp and roots of GN, and EMB-31 in roots and flowers of GN and PA, and unripe pulp of GN. The in silico analysis was efficient in the identification of spatial/time-specific genes, thereby decreasing analysis time and cost, making future genetic transformation studies focusing on the application of these tissue-specific promoters possible.