Functional Analysis of the Coffee (Coffea arabica) 14-3-3 Gene Promoter

Coffee is one of the most important agricultural products in the world, being widely cultivated in tropical countries, for both internal consumption and export. In the last thirty years, several research efforts in genetics and biotechnology have been performed aiming to obtain improved coffee plants with greater disease resistance, high productivity and better quality drink. However, despite the molecular tools currently available, advances in coffee biotechnology are limited. In this context, the availability of highly active coffee promoters with known expression patterns is scarce and further research is needed. With the aim of providing tools for constitutive transgene expression in coffee plants, the present study undertook the functional characterization of the 14-3-3 gene promoter from C. arabica. To this end, the 5`-flaking region of the mentioned gene was transcriptionally fused to the GUS reporter gene and stably transformed in Arabidopsis thaliana Col-0. Histochemical and qPCR analysis of GUS expression in the generated transgenic plants showed variable reporter expression through the three tested developmental stages. In comparison to control plants transformed whit a 35S:GUS cassette, the 14-3-3 promoter drove a less intense and ubiquitous expression of the reporter gene than the one promoted by 35S.