Shelter covering altered polyamines accumulation of cherry (Prunus pseudocerasus Lindl.) via elevating the expression of spermidine synthase (SPDS) gene

•Shelter covering for cherry might substantially enhance the expression of Spermine synthase (SPDS) gene.•Shelter covering can alter PAs accumulation, including putrescine (Put), spermidine (Spd), and spermine (Spm), which at least partially improved fruitsetting of Chinese cherry in rainy regions.•Subcellular localization detected that CpSPDS gene was located in both nucleus and cytoplasm. Polyamines (PAs), including putrescine (Put), spermidine (Spd), and spermine (Spm), play key roles in plant growth, development, and abiotic/biotic stress tolerance. Their functions appear to be intimately related to their synthesis, which occurs via arginine/ornithine decarboxylase (ADC/ODC), Spd synthase (SPDS) and Spm synthase (SPMS) etc. Previously, the transcriptional regulation of cherry under the shelter covering was carried out, and the PA synthase-related genes, particularly spermidine synthase (SPDS) gene, were differentially expressed in the fruits as exposure to the shelter covering. In the present work, the full-length cDNA sequence of this gene was cloned and named as CpSPDS (GenBank accession: MK045261). Bioinformatics analysis indicated that the cDNA sequence of CpSPDS was 1243 bp in length. Cluster analysis showed that CpSPDS had the highest homologies with those of sweet cherry (XP 021826297, 100 %) and peach (XP 020413638, 99 %). Subcellular localization detected that target gene was located in both nucleus and cytoplasm. The qPCR quantification showed that CpSPDS was differentially expressed in alabastrums, fruitlets, mature fruits and mature leaves of cherry. Interestingly, shelter covering significantly improved the fruitsetting in comparison with those from the shelter-free, gave a positive effect on the expression of CpSPDS gene. The endogenous free PAs were quantified in different tissues by high-performance liquid chromatography (HPLC). The PAs contents of the sheltered trees, i.e. Put, Spm and Spd were diversely higher in comparison to the shelter-free, especially in alabastrums, whose Spd titer of the sheltered was 3.29 folds higher than that of the unsheltered, which somehow collaborated result of mRNA quantification. Therefore, shelter covering for cherry might substantially enhance the expression of CpSPDS gene, leading to altering PAs accumulation, which at least partially contributed to the elevation in fruitsetting in rainy regions.