Insight into the expression variation of metal-responsive genes in the seedling of date palm (Phoenix dactylifera). (April 2018)

• Record Type: Journal Article
• Authors: Chaâbene, Zayneb; Rorat, Agnieszka; Rekik Hakim, Imen; Bernard, Fabien; Douglas, Grubb C.; Elleuch, Amine; Vandenbulcke, Franck; Mejdoub, Hafedh
• Is Part Of: Chemosphere. Volume 197(2018)
• Page Start: 123
• Page End: 134
• Publication Date: 2018-04
• Subjects: Biomarkers -- Date palm hypocotyls -- Gene normalization -- Reference gene validation -- Gene expression -- Detoxification mechanisms; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2017.12.146
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Phytochelatin synthase and metallothionein gene expressions were monitored via qPCR in order to investigate the molecular mechanisms involved in Cd and Cr detoxification in date palm ( Phoenix dactylifera ). A specific reference gene validation procedure using BestKeeper, NormFinder and geNorm programs allowed selection of the three most stable reference genes in a context of Cd or Cr contamination among six reference gene candidates, namely elongation factor α1, actin, aldehyde dehydrogenase, SAND family, tubulin 6 and TaTa box binding protein. Phytochelatin synthase ( pcs ) and metallothionein ( mt ) encoding gene expression were induced from the first days of exposure. At low Cd stress (0.02 mM), genes were still up-regulated until 60th day of exposure. At the highest metal concentrations, however, pcs and mt gene expressions decreased. pcs encoding gene was significantly up-regulated under Cr exposure, and was more responsive to increasing Cr concentration than mt encoding gene. Moreover, exposure to Cd or Cr influenced clearly seed germination and hypocotyls elongation. Thus, the results have proved that both analyzed genes participate in metal detoxification and their expression is regulated at transcriptional level in date palm subjected to Cr and Cd stress. Consequently, variations of expression of mt and pcs genes may serve as early-warning biomarkers of metal stress in this species. Highlights: Reference genes were selected in date palm hypocotyls exposed to Cd and Cr. Phytochelatin synthase gene was upregulated under Cd and Cr stress. Metallothionein less responsive to heavy metal stress than phytochelatin synthase. Identification of potential biomarkers of HMs contamination.