Abstract
BackgroundDate palm, as one of the most important fruit crops in North African and West Asian countries including Oman, is facing serious growth problems due to salinity, arising from persistent use of saline water for irrigation. Although date palm is a relatively salt-tolerant plant species, its adaptive mechanisms to salt stress are largely unknown.ResultsIn order to get an insight into molecular mechanisms of salt tolerance, RNA was profiled in leaves and roots of date palm seedlings subjected to NaCl for 10 days. Under salt stress, photosynthetic parameters were differentially affected; all gas exchange parameters were decreased but the quantum yield of PSII was unaffected while non-photochemical quenching was increased. Analyses of gene expression profiles revealed 2630 and 4687 genes were differentially expressed in leaves and roots, respectively, under salt stress. Of these, 194 genes were identified as commonly responding in both the tissue sources. Gene ontology (GO) analysis in leaves revealed enrichment of transcripts involved in metabolic pathways including photosynthesis, sucrose and starch metabolism, and oxidative phosphorylation, while in roots genes involved in membrane transport, phenylpropanoid biosynthesis, purine, thiamine, and tryptophan metabolism, and casparian strip development were enriched. Differentially expressed genes (DEGs) common to both tissues included the auxin responsive gene, GH3, a putative potassium transporter 8 and vacuolar membrane proton pump.ConclusionsLeaf and root tissues respond differentially to salinity stress and this study has revealed genes and pathways that are associated with responses to elevated NaCl levels and thus may play important roles in salt tolerance providing a foundation for functional characterization of salt stress-responsive genes in the date palm.
Highlights
Date palm, as one of the most important fruit crops in North African and West Asian countries including Oman, is facing serious growth problems due to salinity, arising from persistent use of saline water for irrigation
The results indicated that the salt-stress induced changes in gene expression for majority (~70%) of the tested genes was consistent between both approaches (RNA-seq and Reverse transcriptase-quantitative (qPCR)), and in leaves (Fig. 6a) and roots (Fig. 6b)
The transcriptomic data in the present study indicated that stress-responsive genes are mainly associated with photosynthetic and photorespiratory pathways in leaves, while transcription regulation, transmembrane transport, apoplastic component, proteolysis, and Adenosine triphosphate (ATP) and metal binding pathways were found in the roots
Summary
As one of the most important fruit crops in North African and West Asian countries including Oman, is facing serious growth problems due to salinity, arising from persistent use of saline water for irrigation. Soil salinity is a global problem, which severely affects the agricultural production and the total organic stock on our planet [1, 2]. This problem becomes greater in regions with dry climates, sporadic rainfall and high temperatures, leading to high evapotranspiration rates [3]. All of these agriculturally devastating factors are common in some arid and semi-arid regions of the Mideast and North Africa, where date palm Salt-tolerant plants have evolved several mechanisms to cope with the osmotic and ion toxicity effects that include extrusion of the salts and compartmentation of Na+ ions in the vacuole [12, 13] and the production of osmolytes such as carnitine, fructans, glutamate, glycine-betaine, inorganic ions like K+, mannitol, oligosaccharides, proline, polyols, sorbitol, sucrose and trehalose [14] as well as enhanced enzymatic (SOD, catalase, peroxidases) and non-enzymatic (glutathione, ascorbic acid, anthocyanins, etc) antioxidants [6, 7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
