Résumé
Rationale. Plants have biochemical mechanisms to cope withabiotic stress and respond to such conditions by changing the expression of many genes, such as those belonging to the DREB subfamily. DREB is a transcription factors that plays important roles in regulating the expression of genes in response to a variety of abiotic and biotic stresses (Yamaguchi-Shinozaki and Shinozaki, 2005). The comprehension of regulation of CcDREB1D promoters in coffee during a representative range of abiotic stress such as drought, cold, heat, photo-oxidative stress and abscisic acid (ABA) depends on understanding the transcriptional activity of allelic and homolog forms of this promoter isolated from clones of C. canephora combined with RNA-seq data. Methods. In orderstudy the regulation of CcDREB1D promoters to abiotic stresses, binary vectors harboring three different haplotypes of this CcDREB1D cloned in front of the uidA reporter gene, were constructed and used to transform C. arabica cv Caturra. The functional analysis of the CcDREB1D promoter haplotypes under the first 20 hours of different abiotic stresses was performed byperforming GUS histochemical assays and by checking uidA gene expression. Results. The expression of the uidA reporter gene under different abiotic stresses in leaves, meristems and roots of transgenic coffee plants enabled to fully characterize the CcDREB1D promoter specificity, with expression levels ranging from low to high levels depending of CcDREB1D promoter haplotype and abiotic stress applied. Conclusions and perspectives. Our results showed that specific and spatio-temporal expression of the pCcDREB1D occured in plant tissues/organs of transformed plants of C. arabica. These results also revealed the specific activity of the promoter CcDREB1D in guard cells of stomata during drought stress. RNA-Seq data and RT-qPCR are underway to confirm these histochemical results. (Texte intégral)