*2.1. Genome-Wide Identification of the SWEET Family Genes in R. chinensis*

A total of 29 SWEET proteins were identified on the basis of HMM profiles of the SWEET domain (PF03083) search results. Meanwhile, 28 SWEET homologous proteins were obtained by using 17 protein sequences of AtSWEETs to BLASTP in the *R. chinensis* proteome with an e-value threshold of 1 × <sup>10</sup>−5. After the intersection of these two results, 25 *SWEET* genes were finally identified in *R. chinensis* according to the conserved domains in the relevant database (Table 1). These genes were named from *RcSWEET1* to *RcSWEET17b* according to their homology with *A. thaliana*. Protein characterization analysis showed that the ranges of genomic DNA (gDNA) and coding sequences (CDS) are 717~3289 bp and 708~933 bp, respectively. The amino acid length of RcSWEET family members ranged from 235 (RcSWEET2a, RcSWEET2b, and RcSWEET5c) to 310 (Rc-SWEET12), and the average molecular weight (MW) ranged from 26,284.25 (RcSWEET2b) to 34,702.73 (RcSWEET12). The range of the theoretical isoelectric point (pI) is between 5.93 (RcSWEET15b) and 10.11 (RcSWEET10c). The TMHMM predicted results showed that all 25 RcSWEET proteins contained 7 transmembrane domains, indicating that the transmembrane structure of RcSWEET proteins was relatively conservative (Figure S1).


**Table 1.** Characteristics of the *RcSWEET* gene family members in *R. chinensis* 'Old Blush'.


**Table 1.** *Cont.*
