Novel Transcriptome Study Provides New Insights on Date Palm Response to Copper Stress

Abstract

Zayneb Chaâbene, Imen Hakim Rekik, Amine Elleuch, Hafedh Mejdoub and Franck Vandenbulcke

To disclose the transcriptomic basis of date palm Phoenix dactylifera exposed to copper, massive reprogramming of gene expression, with differentially expressed genes identified in cv Deglet Nour cDNA library was predicted using GeneMANIA program. Cu-transcription factors (TFs) were well-characterized including SQUAMOSA promoter binding protein-like (SPL). Co-regulation between genes of the same family like fsd (coding FeSOD) and of different families, fsd and csd (Cu/Zn SOD) were predicted. Other Co-expression links between Cu-transporters responsible for metal uptake such as copt (for COPper Transporter) or for metal transport between vacuole and cytoplasm like Nramp (for natural resistance associated macrophage proteins) or for Cu-efflux to the vacuole like abcc (ATP-Binding Cassette) were predicted. Monitoring of selected candidate genes expressions was performed in in vitro generated genetically homogeneous tissues: explant of Deglet Nour, exposed to Cu stress. Pdpcs1, Pdmt3, Pdabcc, Pdhma2, Pdmate5 and PdNramp6 were unregulated significantly by metal concentrations and time exposure except for Pdpcs1. This later gene did not decrease by increasing metal stress during experience showing its crucial involvement in metal tolerance. However, for the other genes amounts of transcript levels significantly decreased by increasing metal and exposure time which induced signs of alteration in explants.

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