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Esumi, T.

Publications and source records attributed to Esumi, T..

3 recordsLinked to original sources

Propagation path of a flowering cherry (Cerasus x yedoensis) cultivar 'Somei-Yoshino' traced by somatic mutations

Flowering cherry cultivar Somei-Yoshino (Cerasus x yedoensis) has been clonally propagated and spread all around the world including Japan. Somei-Yoshino is thought to be an interspecific hybrid derived from C. spachiana and C. speciosa; however, its origin is unclear. Since somatic mutations are randomly induced in genomes and stably transmitted through generations, we aimed to identify somatic mutations in the genome of Somei-Yoshino to trace its propagation path. A total of 46 Somei-Yoshino clones were collected from all over Japan and subjected to whole-genome sequencing. The results revealed 684 single nucleotide variants, of which 71 were found in more than two clones. Clustering analysis of the 46 clones using these 71 variants revealed six groups, four of which contained 40 of the 46 clones. In addition, because each of the four clones closely planted in Ueno Park, Tokyo, Japan, clustered into the four different groups, we considered that these four clones could be the ancestors of the Somei-Yoshino clones found in Japan. Furthermore, based on the comparison of mutant alleles with the genomes of Cerasus species, one of the four trees was concluded as the closest to the origin. Here, we propose that the origin of Somei-Yoshino is a chimera derived from at least four somatic mutants.

plant biology↗

Transcriptome Dynamics of Floral Organs Approaching Blooming in the Flowering Cherry (Cerasus x yedoensis) Cultivar 'Somei-Yoshino'

To gain insights into the genetic mechanisms underlying blooming and petal movement in flowering cherry (Cerasus x yedoensis), we performed time-course RNA-seq analysis of the floral buds and open-flowers of the most popular flowering cherry cultivar, Somei-Yoshino. Independent biological duplicate samples of floral buds and open-flowers were collected from Somei-Yoshino trees grown at three different locations in Japan. RNA-seq reads obtained from floral bud and open-flower samples collected in the current study (in 2019) and in a previous study (in 2017) were aligned against the genome sequence of Somei-Yoshino to quantify gene transcript levels. Clustering analysis of RNA-seq reads revealed dynamic changes in the transcriptome, with genes in seven modules predominantly expressed at specific time points, ranging from 5 weeks before flowering to 2 weeks after flowering. Based on the identified gene modules and Gene Ontology (GO) terms enriched at different floral stages, we speculate that the genetic mechanisms underlying petal movement and flower opening in cherry involve the processes of development, cell wall organization, reproduction, and metabolism, which are executed by genes encoding transcription factors, phytohormones, transporters, and polysaccharide metabolic enzymes. Furthermore, we propose a method for cherry bloom forecasting, based on gene expression levels at different time points before flowering as RNA markers.

plant biology↗

Phased genome sequence of an interspecific hybrid flowering cherry, Somei-Yoshino (Cerasus x yedoensis)

We report the phased genome sequence of an interspecific hybrid, the flowering cherry Somei-Yoshino (Cerasus x yedoensis). The sequence was determined by single-molecule real-time sequencing technology and assembled using a trio-binning strategy in which allelic variation was resolved to obtain phased sequences. The resultant assembly consisting of two haplotype genomes spanned 690.1 Mb with 4,552 contigs and an N50 length of 1.0 Mb. We predicted 95,076 high-confidence genes, including 94.9% of the core eukaryotic genes. Based on a high-density genetic map, we established a pair of eight pseudomolecule sequences, with highly conserved structures between two genome sequences with 2.4 million sequence variants. A whole genome resequencing analysis of flowering cherry varieties suggested that Somei-Yoshino is derived from a cross between C. spachiana and either C. speciose or its derivative. Transcriptome data for flowering date revealed comprehensive changes in gene expression in floral bud development toward flowering. These genome and transcriptome data are expected to provide insights into the evolution and cultivation of flowering cherry and the molecular mechanism underlying flowering.

genomics↗