Transcriptomic analysis of Aegilops tauschii during long-term salinity stress
Aegilops tauschii is the diploid progenitor of the bread wheat D-genome. It originated from Iran and is a source of abiotic stress tolerance genes. However, little is known about the molecular events of salinity tolerance in Ae. tauschii. This study investigates the leaf transcriptional changes associated with long-term salt stress. Total RNA extracted from leaf tissues of control and salt-treated samples was sequenced using the Illumina technology, and more than 98 million high-quality reads were assembled into 255,446 unigenes with an average length of 1398 bp and an N50 of 2269 bp. Functional annotation of the unigenes showed that 93,742 (36.69%) had at least a significant BLAST hit in the SwissProt database, while 174,079 (68.14%) showed significant similarity to proteins in the NCBI nr database. Differential expression analysis identified 4506 salt stress-responsive unigenes. Bioinformatic analysis of the differentially expressed unigenes (DEUs) revealed a number of biological processes and pathways involved in the establishment of ion homeostasis, signaling processes, carbohydrate metabolism, and post-translational modifications. Fine regulation of starch and sucrose content may be important features involved in salt tolerance in Ae. tauschii. Moreover, 82% of DEUs mapped to the D-subgenome, including known QTL for salt tolerance, and these DEUs showed similar salt stress responses in other accessions of Ae. tauschii. These results could provide fundamental insight into the regulatory process underlying salt tolerance in Ae. tauschii and wheat and facilitate identification of genes involved in their salt tolerance mechanisms.
KeywordsAegilops tauschii RNA sequencing Unigene De novo assembly Salinity tolerance
Differentially expressed unigenes
Basic local alignment search tool
Quantitative real-time PCR
MM, MRN, HA, and GM-N conceived and designed the research. MM and SAM performed the experiments and analyzed the data. MM, MRN, HA, SAM, and YT interpreted the results and wrote the manuscript. MRN, HA, GM-N, and GHS supervised the study. All authors read and approved the manuscript.
This study was supported by a grant from the Iran National Foundation Science (project number: 90003984).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
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