Abstract
Background: Pear is one of the most abundant fruit crops and has been cultivated world-wide. However, the salt injury events caused by increased salinity limited the distribution and sustainable production of pear crops. Therefore, it is needed to take further efforts to understand the genetics and mechanisms of salt tolerance to improved salt resistance and productivity.Results: In this work, we analyzed the dynamic transcriptome of pear (Pyrus ussuriensis Maxim) under salt stress by using RNA-Seq and WGCNA. A total of 3540, 3831, 8374, 6267 and 5381 genes were identified that were differentially expressed after exposure to 200mM NaCl for 4, 6, 12, 24 and 48 hours, respectively, and 1163 genes were shared among the five comparisons. KEGG enrichment analysis of these DEGs (differentially expressed genes) revealed that “MAPK signaling” and “Plant hormone signal transduction” pathways were highly enriched. Meanwhile, 622 DEGs identified from WGCNA were highly correlated with these pathways, and some of them were able to indicate the salt tolerance of pear varieties. In addition, we provide a network to demonstrate the time-sequence of these co-expressed MAPK and hormone related genes.Conclusion: A comprehensive analysis about salt-responsive pear transcriptome were performed by using RNA-Seq and WGCNA. We demonstrated that “MAPK signaling” and “Plant hormone signal transduction” pathways were highly recruited during salt stress, and provided new insights into the metabolism of plant hormones related signaling at transcriptome level underlying salt resistance in pear. The dynamic transcriptome data obtained from this study and these salt-sensitive DEGs may provide potential genes as suitable targets for further biotechnological manipulation to improve pear salt tolerance.