Comparative Transcriptome Profiling of Glycine soja Roots Under Salinity and Alkalinity Stresses Using RNA-seq

Saline-alkaline stress can dramatically inhibit plant growth and limit crop production. Wild soybean(Glycine soja) is a crop that adapts well to such environmental stresses. In this study, RNA-sequencing technology was used to analyze the transcriptome profiles of G. soja roots subjected to 50 mmol · LNaHCOand 150 mmol ·LNaCl treatments. Totally, 2 125 differentially-expressed genes(DEGs) after NaCl treatment and 1 839 DEGs after NaHCOtreatment were identified. The top 14 DEGs revealed by RNAseq were analyzed using qRT-PCR(quantitative real-time polymerase chain reaction). Gene ontology(GO) annotation showed tha most of DEGs under salt and alkali stresses were enriched in "metabolic process", "catalytic activity" and "binding" terms. To search for transcription factors(TFs) among DEGs, the data were screened against TF database PlantTFDB, and it was found that five TF families, Apetala2/ethylene-responsive element binding proteins(AP2-EREBP), V-myb avian myeloblastosis viral oncogene homolog(MYB), WRKYGQK and Zinc finger motif(WRKY), NAM, ATAF1/2, CUC1/2(NAC) and Cys2/His2(C2H2) were involved in sal stress response. Other five TF families, NAC, WRKY, MYB, AP2-EREBP and bZIP were involved in response to alkali stress. These two stress treatments shared NAC, WRKY, AP2-EREBP and MYB, and the only two different TFs were bZIP and C2H2. Forty-eigh MYB TFs were differentially expressed under salt and alkali stresses, and most of them were up-regulated. This study provided usefu information for further investigation of DEGs and TFs in response to saline and alkaline stresses and helped in understanding the molecular basis of the response of G. soja to saline and alkaline stresses.