Differentially expressed gene analysis of Tamarix chinensis provides insights into NaCl-stress response

Salinity is an environmental stress that limits plants' growth and crop yield. High salinity evokes multiple abiotic stresses on plants and affects plants' life almost in all respects. To avoid the grain yield reduction induced by global increases in soil salinization, Tamarix chinensis, being a salt-tolerant tree species, is an appropriate material for plants' salt-tolerance genes examining and tolerance mechanisms investigating. 59,331 unigenes were assembled by transcriptome sequencing of T. chinensis roots under sodium chloride (NaCl) stress, using Illumina HiSeq 2000. Of these unigenes, 45.58% had significant hits in seven databases. 9886, 8153, and 19,938 unigenes were subdivided into 28 KOG (EuKaryotic Orthologous Groups) groups, 29 KEGG Kyoto Encyclopedia of Genes and Genomes) pathways, and 47 GO Gene ontology) terms, respectively. A gene expression profile was built, and 1251 DEGs differentially expressed genes) were identified and classified into ten expression patterns. From the 59,331 unigenes, we predicted about 3000 general NaCl-stress responsive genes. Especially, we predicted several specific salt-tolerance candidate genes by comprehensive analysis of DEGs. Given that all the responsive genes were potential salt-tolerance determinants, we described their roles on the frame of salt-signaling pathway and this could be a systematic guide for following salt-tolerance studies.