Stable and efficient transformation of apple.

Apple is one of precious fruit crop grown in temperate zone. In the post genomic era, the analysis of gene functions in horticultural crops such as apple is required for agricultural utilization. For analysis of such crops, the protocol establishment of tissue culture and transformation is essential.

Characterization of Homologs in Apple as a Model for Fruit Trees.

To elucidate the molecular mechanism of juvenility and annual flowering of fruit trees, (), an integrator of flowering signals, was investigated in apple as a model. We performed sequence and expression analyses and transgenic experiments related to juvenility with annual flowering to characterize the apple homologs . The phylogenetic tree analysis, which included other MADS-box genes, showed that both MdFLC1 and MdFLC3 belong to the same FLC group.

The use of a fertile doubled haploid apple line for QTL analysis of fruit traits.

Apple is an economically important crop, and various approaches to genetic analysis in breeding programs have been attempted, including the production of doubled haploid (DH) lines, which are genetically homozygous. In this study, we used a DH line for QTL analyses, for the first time in a fruit tree, expecting it to simplify the analysis of the inheritance of quantitative traits and thus to enhance QTL detection power. Using an F population from 'Prima' × 'Apple Chukanbohon 95P6' (DH), we constructed a genetic map of 'Prima', and identified 19 QTLs for 13 traits.

CRISPR-Cas9-mediated genome editing in apple and grapevine.

The CRISPR-Cas9 genome-editing tool and the availability of whole-genome sequences from plant species have revolutionized our ability to introduce targeted mutations into important crop plants, both to explore genetic changes and to introduce new functionalities. Here, we describe protocols adapting the CRISPR-Cas9 system to apple and grapevine plants, using both plasmid-mediated genome editing and the direct delivery of CRISPR-Cas9 ribonucleoproteins (RNPs) to achieve efficient DNA-free targeted mutations in apple and grapevine protoplasts. We provide a stepwise protocol for the design and transfer of CRISPR-Cas9 components to apple and grapevine protoplasts, followed by verification of highly efficient targeted mutagenesis, and regeneration of plants following the plasmid-mediated delivery of components.

Expression and functional analysis of apple on flower and fruit formation.

Apple has a transcription factor with MADS domain. Moreover, it is expressed specifically at petals and carpels. The product forms a dimer with () protein as a class B gene for floral organ formation.

Efficient Genome Editing in Apple Using a CRISPR/Cas9 system.

Genome editing is a powerful technique for genome modification in molecular research and crop breeding, and has the great advantage of imparting novel desired traits to genetic resources. However, the genome editing of fruit tree plantlets remains to be established. In this study, we describe induction of a targeted gene mutation in the endogenous apple phytoene desaturase (PDS) gene using the CRISPR/Cas9 system.

The analysis of transgenic apples with down-regulated expression of .

In parthenocarpic cultivars of apple (× Borkh.), () expression has been suppressed by retrotransposon insertion into the genome. In this study, transgenic apple lines were produced that exhibited the same level of depression.

Expression patterns of several floral genes during flower initiation in the apical buds of apple (Malus × domestica Borkh.) revealed by in situ hybridization.

The apple (Malus × domestica Borkh.) is one of the commercially important fruit crops in the worldwide. The apple has a relatively long juvenile period (up to 4 years) and a long reproductive period between the flower initiation and the mature fruit (14-16 months), which prevent the fruit breeding.

Promotion of flowering and reduction of a generation time in apple seedlings by ectopical expression of the Arabidopsis thaliana FT gene using the Apple latent spherical virus vector.

Tree crops have a long juvenile period which is a serious constraint for genetic improvement and experimental research. For example, apple remains in a juvenile phase for more than five years after seed germination. Here, we report about induction of rapid flowering in apple seedlings using the Apple latent spherical virus (ALSV) vector expressing a FLOWERING LOCUS T (FT) gene from Arabidopsis thaliana.

An efficient method for sonication assisted Agrobacterium-mediated transformation of coat protein (CP) coding genes into papaya (Carica papaya L.).

An efficient method for the production of transgenic papaya was developed via Sonication Assisted Agrobacterium-mediated Transformation (SAAT) of somatic embryos. The plasmid pGA482G was modified to contain gene PTi-Epj-TL-PLDMV with CP coding sequence of PLDMV Japan strain and chimeric gene PTi-NP-YKT with multiple CP coding sequences from PRSV Taiwan strain, PRSV Hawaii strain and PRSV Thailand strain, respectively. Disarmed Agrobacterium tumefaciens strain LBA4404 carrying the binary plasmid pGA482G with the CP genes and nptII gene was used to transform embryo calli of papaya variety Sunset to produce transgenic papaya plants.