Crosstalk between long non-coding RNAs and miRNAs regulates transferase activities in response to salt stress in Pistachio (Pistacia vera L.)

Abstract

Long non-coding RNA (lncRNA) molecules are important regulators of a broad spectrum of biological processes, including adaptation to diverse stresses in plants. However, how plant lncRNAs function during salt stress conditions is largely unknown. In our study, we identified 48 conserved mature Pistacia vera L. (P. vera) miRNAs among pistachio miRNA precursors and used RNA sequencing data to predict and validate the interaction relationship between lncRNAs and miRNAs. We indicated that the regulatory networks of pve-miRNA-lncRNA-mRNAs were more complex in the salt-tolerant (Ghazvini) compared to the salt-sensitive (Sarakhs) pistachio cultivar under NaCl treatment. We also found that 7 and 8 salt-responsive lncRNAs play a role as competing endogenous target mimics (eTMs) for 7 pve-miRNA families in Ghazvini (mir164, mir169, mir397, and mir827) and Sarakhs (mir156, mir159, mir169, and mir482), respectively. The GO-term enrichment analysis showed that protein-coding target genes of pve-miRNAs that regulated with target mimic relationship mainly enriched in transferase activity include: 7-deoxyloganetin glucosyltransferase, Arginine N-methyltransferase, Glutathione transferase, Flavonol sulfotransferase, and Beta-glucuronosyltransferase. Their activity regulates alkaloids and polysulfated flavonols biosynthesis, sequesters sodium, improves antioxidant capacity and controls epigenetic elements in Ghazvini under salt treatment. In Sarakhs, the analysis of GO-term enrichment in pve-miRNAs protein-coding target genes of lncRNA-related mimic relationship enriched in response to wounding, cell death, and jasmonic acid biosynthetic process. Compared to Sarakhs, Ghazvini had a more effective ceRNA network for regulating transferase enzymes and specific transcription factors including MYB, WRKY, and ABR1 in response to salt stress, which led to more salt tolerance in the Ghazvini cultivar. The present study provides new information about the complex lncRNA-miRNA-mRNA regulatory networks in response to plant stress conditions in pistachio. Furthermore, our findings can be used for different breeding programs and the introduction of salt-tolerant pistachio rootstocks.