Résumé
Previous studies already reported up-regulated expression of M6PR (mannose-6-phosfatase reductase)-encoding genes in leaves of C. canephora (Marraccini et al, 2012) and C. arabica (Freire et al., 2013; de Carvalho et al, 2014) grown in greenhouse or in field conditions under drought stress. Rationale. Our study aims to evaluate the expression of the CcM6PR gene in roots of drought-tolerant (14, 73 and 120) and drought-susceptible (22) clones of C. canephora Conilon (Marraccini et al, 2012) grown in greenhouse with or without controlled water limitations. Methods. For each clone and water condition, total RNA was extracted from roots and the transcriptome profiles was evaluated using 454 sequencing, allowing expression of CcM6PR gene in silica by electronic northern between drought-susceptible and drought-tolerant clones under irrigated and non-irrigated conditions. Expression of CcM6PR gene in roots of these clones was also checked by real-time qPCR analyses. Results. In silico analysis suggested up-regulated expression of CcM6PR gene under drought in roots of both drought-tolerant and drought-susceptible clones of C. canephora. Such up-regulated expression of CcM6PR gene under drought was validated by real-time qPCR, mainly in roots of the drought-tolerant done 14, and to a lesser extent, in those of drought-tolerant (73 and 120) and drought-susceptible (22) clones of C. canephora. Conclusions and Perspectives. Drought-induced expression of M6PR gene was also reported to occur in other higher plants, therefore suggesting that mannitol metabolic pathway plays important roles in protecting coffee roots against water limitation. (Texte intégral)