EN
Genome-wide gene expression profiling was conducted by Solexa sequencing in order to gain insight into the transcriptome dynamics that are associated with salt stress of cotton seedlings. A total of 145,794 and 138,518 clean tags were generated from the control and salinity libraries, respectively. Of these, 75,500 (51.8%) and 72,077 (52.0%) tags were matched to the reference genes. The most differentially regulated tags with a log2ratio >2 or >-2 (P <0.001) were analyzed further, representing 125 up- and 171 down-regulated genes except for unknown transcripts, which were classified into ten functional categories. The most enriched categories were those of metabolism, signaling pathway, environmental response and transcription. Many genes or biological pathways were found to be commonly shared between salt and other abiotic stresses in plants such as genes participating in environmental response, ABA signaling JA signaling, etc. Furthermore, the expression patterns of 12 genes were assessed by quantitative real-time PCR, and the results obtained showed general agreement with the Solexa data. Further analysis indicated the important roles of selected genes in salt tolerance by comparison with the mRNA levels in salt-tolerant cotton cultivar ZM3 with that in salt-sensitive cultivar LM6. Overall, we reveal the complex changes at the transcriptional level during salt stress of cotton seedlings and provide useful starting points for more in-depth analyses of cotton’s salt tolerance.