Cloning and Bioinformatics Analysis of <i>Rosa rugose S</i> Locus F-Box Gene (<i>RrSLF</i>)

Abstract

In order to reveal the phenomenon of R. rugose pollination incompatibility, the full-length cDNA sequence of S Locus F-box Gene was cloned for the first time from the pollen of Rosa rugose “Zilong wochi” with RT-PCR and RACE methods and named as RrSLF . The full-length cDNA is 1236 bp with an open reading frame of 1122 bp, encoding 343 amino acids. The derived protein has a molecular weight of 43.7 kD, a calculated pI of 6.24, an F-box conserved domain at position 343 - 741, and belongs to F-box family. The derived protein is a Hydrophobicity protein secreted into the cytoplasm. There is no transmembrane domain and no signal peptide cleavage site, twenty-one Ser phosphorylation sites, seven Thr phosphorylation sites, seven Tyr phosphorylation sites, two N-glycosylation sites, and no O-glycosylation sites. There are 22.25% α -helixes, 31.37% random coil, 32.17% extended peptide chain, and 14.21% β -corner structure. This protein and the SFB/SLF protein from Rosaceae Prunus fruit, including Prunus speciose , share a sequence homology of 59% - 61%; all of the proteins contain a n F-box conserved domain, two hypervariable regions HVa, HVb, and two variable regions V1, V2. Furthermore, their phylogenetic relationships are consistent with their traditional classifications. These results were meaningful to reveal the molecular mechanism of Rosa rugose pollination incompatibility and improve the theory and techniques of breeding ornamental Rosa rugose .