The transcriptomes of salt-stressed and unstressed Betula kirghisorum plants were analyzed using high throughput sequencing technology. A total of 52,239,804 and 51,772,998 clean reads were obtained from the two libraries, respectively, and de novo assembled into 60,545 all-unigenes. A total of 39,997 unigenes were annotated using public databases. Overall, 7206 genes were differentially expressed in unigenes and were involved in 127 pathways. Thirteen transcription factor families were identified in B.
GRAS transcription factor
GRAS proteins are plant-specific transcription factors that are involved in the regulation of root and shoot growth. Here, we cloned BkGRAS2 from Betula kirghisorum (abbreviated to Bk) and analyzed the physicochemical properties and expression pattern of the encoded protein. BkGRAS2 had an open reading frame of 1614 bp encoding 537 amino acid residues. The deduced BkGRAS2 protein was hydrophilic, and it contained highly conserved VHIID and SAW motifs. BkGRAS1 and BkGRAS2 showed considerable sequence similarities.