*4.5. RNA-Seq Data Analysis*

To investigate the expression patterns of *RcSWEET* genes in different tissues of *R. chinensis* 'Old Blush', organ specificity transcriptome data (PRJNA546486) of the rose, including roots, stems, leaves, stamens, prickles, pistils, and ovaries, was extracted from the NCBI SRA database (https://www.ncbi.nlm.nih.gov/sra/, accessed on 18 December 2022) [47]. The raw data have been listed in Table S6. FPKM (Fragments Per Kilobase of transcript per Million mapped reads) was used to examine the expression levels, and the heatmap of *RcSWEET* genes in different tissues was generated using TBtools based on the log2FPKM values.

The grafted seedlings of *R. beggeriana* 'Old Blush' with the rootstock of *R. multiflora* were placed in a growth chamber with an air temperature of 23 ◦C day/18 ◦C night and a photoperiod of 10 h light/14 h dark. After a week of acclimatization, the grafted seedlings were maintained at 4 ◦C for 0, 1, 6, and 24 h. Current-year shoots of similar thickness and intact leaves were selected as sampling materials, and all the samples were collected in three biological replicates (the data has not been published yet). The Illumina HiSeq2500 highthroughput sequencing platform was used to sequence the cDNA library and obtain the raw data. All high-quality reads of each sample that passed quality control were mapped to the *R. chinensis* 'Old Blush' RchiOBHm-V2 genome. Gene expression levels were calculated as FPKM. The *RbSWEET* genes have been identified, and the transcriptome data are listed in Table S7. The heatmap of *RbSWEET* gene expression profiles was generated using

TBtools based on the log2FPKM values. DEGs were screened according to certain criteria (fold change ≥ 2 and *p*-value ≤ 0.05).
