Genome-wide expression profiling in leaves and roots of date palm (Phoenix dactylifera L.) exposed to salinity.
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. Although date palm is a relatively salt-tolerant plant species, its adaptive mechanisms to salt stress are largely unknown.



In 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.



Leaf 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.
Department of Biology, College of Science, Sultan Qaboos University, Muscat, Oman. myaish@squ.edu.om.
Mahmoud W
0000-0002-5171-3014
MW
Yaish
Department of Biology, College of Science, Sultan Qaboos University, Muscat, Oman.
Himanshu V
HV
Patankar
Department of Biology, College of Science, Sultan Qaboos University, Muscat, Oman.
Dekoum V M
DVM
Assaha
Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, 650500, China.
Yun
Y
Zheng
Department of Crop Science, College of Agriculture and Marine Sciences, Sultan Qaboos University, Muscat, Oman.
Rashid
R
Al-Yahyai
Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA.
Ramanjulu
R
Sunkar
D019295:Computational Biology / Q000379:methods; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D063990:Gene Ontology; D059014:High-Throughput Nucleotide Sequencing; D058977:Molecular Sequence Annotation; D065749:Phoeniceae / Q000235:genetics*; D010788:Photosynthesis / Q000235:genetics; D018515:Plant Leaves / Q000235:genetics*; D018517:Plant Roots / Q000235:genetics*; D019655:Quantitative Trait, Heritable; D054712:Salinity; D055049:Salt Tolerance / Q000235:genetics*; D013312:Stress, Physiological / Q000235:genetics; D059467:Transcriptome
DEGs; RNA-seq; date palm; differentially expressed genes; leaves; roots; salinity