Identification of APC/C regulators in tomato
We isolated tomato homologs of APC/C regulators through BLAST analysis in the website (www.solgenomics.net). Tomato has only one UVI4homologous gene Solyc10g080400 in the genome referred asSlUVI4 , which is different with other plant species such as Arabidopsis, rice, maize, strawberry, etc. We further identifiedUVI4 homologous genes in other Solanaceae species, and revealed that pepper, potato and eggplant have one UVI4 homolog, and tobacco and petunia have four and three homologs in the draft genome, respectively (Supplementary Figure S1A). Similar to Arabidopsis, tomato has three CCS52 homologous genes referred as SlCCS52s including Solyc08g080080(SlCCS52A1 , previously named as SlCCS52A ),Solyc12g056490 (SlCCS52A2 ) and Solyc06g043150(SlCCS52B ) and four CDC20 homologous genes referred asSlCDC20s including Solyc03g096870 (SlCDC20.1 ),Solyc08g005420 (SlCDC20.2 ), Solyc06g072830(SlCDC20.3 ) and Solyc03g095210 (SlCDC20.4 ) (Supplementary Figure S1B). SlCCS52A2 is newly isolated in tomato genome, and its amino acid sequence has 83.05% and 57.75% identity with SlCCS52A1 and SlCCS52B, respectively (Figure S2). We analyzed subcellular localizations of SlUVI4 and SlCCS52 proteins, and revealed that all of them have nuclear localization (Figure S3). SlCCS52A1 also has strong plasma membrane localization, and SlCCS52B has weak cytoplasmatic localization. We further tested the interactions between SlUVI4 and SlCCS52 proteins, and both yeast-two hybrid and bimolecular fluorescence complementation assay (BIFC) revealed that SlUVI4 could interact with SlCCS52A1 and SlCCS52A2, but not with SlCCS52B (Figure 2). All these data suggest that SlUVI4 and SlCCS52 genes might have similar functions as those in Arabidopsis.