Novel insight of the SVP gene involved in pedicel length based on genomics analysis in cherry.

Abstract

Key message: PcSVP was identified based on Prunus conradinae genome and was further overexpressed in A. thaliana to comfirm it was a key factor in flower development, causing the pedicels elongation. Prunus conradinae is an endemic plant resource in China with high ornamental and economic values. To generate useful genomic resources for expanding insights into the evolutionary history of this important plant, the chromosome-level genome and organelle genomes of P. conradinae are de novo assembled and functionally annotated. The chromosome-level haploid genome of autotetraploid P. conradinae was assembled with 262.79 Mb with 27,802 protein-coding genes annotated. The complete chloroplast and mitochondrial genome of P. conradinae are found to be 157,715 bp and 434,334 bp, respectively. According to evolutionary analysis, P. conradinae was closely related to P. serrulata and P. yedoensis, and they diverged from their common ancestor approximately 6.0 million years ago. There were 108 gene families that significantly expanded during P. conradinae evolution and 56 shared positively selected genes. Selective sweep analysis based on the whole-genome resequencing of wild cherries from Fujian and Zhejiang indicated that genes involved in flower development and stress responses were potentially under selection. Pedicel length varied greatly among Prunus species and was a significant identifying characteristic. Ectopic overexpression of PcSVP in Arabidopsis thaliana suggested that it was a key factor in flower development, causing the sepals curling and pedicels elongation. These findings will contribute to the discovery of key functional genes involved in the agronomic or biological traits of P. conradinae, as well as the future development, utilisation and germplasm conservation of wild cherries.