Comparative Transcriptome Analysis of Leaves of Sour Jujube Seedlings under Salt Stress

Abstract Sour jujube ( Ziziphus jujuba Mill. var. spinosa ) is a native tree species in China. It is often used as the rootstock of jujube, its fruit can also be used as medicine. So it has high scientific and ecological value. Sour jujube is mostly planted in Northwest China and has extremely high salt tolerance. But the molecular mechanism of its salt tolerance is rarely studied. This study was carried out in the laboratory of Environment and Resources College of Dalian Nationalities University, two treatments were performed on the leaves of sour jujuba seedlings, the experimental group (H3): 300 mM Nacl for 3 h, and the control group (CK): sterile water for 3 h. A total of 47.02GB of valid data and 32730 annotated genes were obtained. Based on the analysis of gene expression in the comparison group, a total of 2295 genes with significant differential expression were obtained, of which 807 were up-regulated and 1488 were down-regulated. According to gene function annotation and enrichment analysis, we finally screened 148 genes. These genes were mainly involved in signal transduction of plant hormones (38), homeostasis of cell walls (27), secondary metabolism of organic matter (32), redox reactions (20) in leaves of sour jujuba seedlings under salt stress. It was also accompanied by some stress-related transcription factors (31). In addition, under salt stress, raffinose family oligosaccharides (RFO) metabolism of sour jujube seedlings was accelerated. Studying the molecular response of sour jujuba seedlings under salt stress provides a scientific basis for its cultivation in saline areas and is beneficial to further improve the salt tolerance of grafted jujube trees.