SRA

Salinity seriously reduces the yield and quality of crops. Silicon (Si) has been widely reported to have beneficial effects on plant growth and development under salt stress. However, the mechanism is still poorly understood. In an attempt to identify genes or gene networks that may be orchestrated to improve salt tolerance of cucumber plants, we profiled the RNA-seq transcriptomes of both control and salt-stressed cucumber leaves in the presence or absence of added Si. The comparative transcriptome analysis revealed that Si plays an important role in shaping the transcriptome of cucumber: the expression levels of >1,000 genes (differtially expressed genes, DEGs) were changed in response to Si treatment as compared with the control, and these genes were mainly involved in ion transport, hormone and signal transduction, biosynthesis and metabolic processes, stress and defense responses, and antioxidant activity. Under salt stress, many genes functionally associated with metabolic processes and responses to environmental stimuli were strongly up- or down-regulated in their expressions. Si treatment showed a tendency that induced the transcriptomic profile of salt-stressed cucumber back to that of the control with large majority of Na down-regulated DEGs and about half of Na up-regulated DEGs being adjusted back to CT levels. This study provides a novel insight into the mechanism for Si-mediated alleviation of salt stress in plants at the transcriptome level, and it suggests that Si may act as an elicitor to precondition cucumber plants and induce salt tolerance. Overall design: Transcriptome profiles of both control and salt-stressed cucumber leaves in the presence or absence of added Si were generated by deep sequencing, in triplicates, using Illumina HiSeq 2500.