Cloning and expression analysis of the dehydrin gene PlDHN1 in peony (Paeonia lactiflora)

摘要

Dehydrins (DHNs) proteins play a protective role in plants under different abiotic stress conditions. In this study, a stress-responsive dehydrin gene PlDHN1 (GenBank accession number: KX524516) was cloned from the buds of the Paeonia lactiflora 'Dafugui'. The PlDHN1 gene contained a 783-bp open reading frame (ORF) that encoded 260 amino acids. Sequence alignment and phylogenetic analysis showed that the PlDHN1 sequence possessed an 8-serine residue stretch followed by three conserved repeats of a lysine-rich segment, characteristic of the typical SK3-type dehydrin. Gene structural analysis demonstrated that PlDHN1 contained one 334-bp intron, which included many cis-acting elements known to be involved in gene expression regulation. Subcellular localisation analysis revealed that the PlDHN1 protein was mainly detected in the cytomembrane and nucleus. qRT-PCR analysis indicated that the PlDHN1 gene was more highly expressed in buds than in other tissues. Furthermore, the PlDHN1 transcript in buds accumulated during the winter and peaked in harsh December with gradual decrease prior to spring. The expression of PlDHN1 was up-regulated in response to cold, heat, waterlogging and abscisic acid (ABA) treatment, most significantly for heat and waterlogging. Overall, these results will provide insights into the molecular basis and future genetic engineering of peony resistance against abiotic stresses.