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The Solanaceae family includes the largest flowering crops such as tomatoes, potatoes, and eggplants. Consumer demand has led to massive development of plants in the Solanum genus, and many different Solanum varieties are now available on the market. The recent advances in Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-based genome editing have allowed laboratories and smaller crop production companies to utilize the technology in various crops. The traditional transformation method in crops involves the use of Agrobacterium, which is considered the most efficient method for introducing exogenous genetic materials in target plants. The Agrobacterium-mediated transformation method has been also established in the Solanaceae family, enabling CRISPR/Cas-based genome editing in crops like tomatoes, potatoes, and eggplants. However, the Agrobacterium-mediated approach inevitably accompanies the insertion of exogenous DNA into the plant genome and often causes the formation of chimera that require further propagation steps. Alternatively, the CRISPR/Cas components can be introduced into protoplasts in the form of DNA for transient expression or a mixture of protein and RNA to avoid genomic insertion of foreign materials. The protoplast transformation approach involves processes including protoplast preparation, transfection, and regeneration, which require a comprehensive understanding and greater technical mastery of the tissue culture phase. Here we highlight the current research advances in protoplast transformation and discuss how to optimize the procedures of protoplast isolation, transfection, and regeneration for efficient and reproducible CRISPR/Cas-based genome editing in the genus Solanum.

Isoflavonoids are a class of biologically active natural products that accumulate in soybean (Glycine maxL.) seeds during development, play vital roles in plant defense, and act as phytoestrogens with important human health benefits. Plant cell suspension cultures represent an excellent source of biologically important secondary metabolites. We found that methyl jasmonate (MJ) treatment increased isoflavone production in soybean suspension cell cultures. To investigate the underlying mechanism, we examined the expression of structural genes (CHS6, CHS7, CHI1, IFS1, IFS2, IFMaT, and HID) in the isoflavonoid biosynthesis pathways in soybean suspension cells under various abiotic stress conditions. MJ treatment had the most significant effect on gene expression and increased the production of three glycosidic isoflavones (daidzin, malonyldaidzin, and malonylgenistin), with the maximum total isoflavone production (∼10-fold increase) obtained on day 9 after MJ application. MJ treatment significantly increased total phenolic contents and upregulated isoflavonoid biosynthesis genes, shedding light on the underlying mechanism.

To determine whether Fourier transform (FT)-IR spectral analysis combined with multivariate analysis of whole-cell extracts from ginseng leaves can be applied as a high-throughput discrimination system of cultivation ages and cultivars, a total of total 480 leaf samples belonging to 12 categories corresponding to four different cultivars (Yunpung, Kumpung, Chunpung, and an open-pollinated variety) and three different cultivation ages (1 yr, 2 yr, and 3 yr) were subjected to FT-IR. The spectral data were analyzed by principal component analysis and partial least squares-discriminant analysis. A dendrogram based on hierarchical clustering analysis of the FT-IR spectral data on ginseng leaves showed that leaf samples were initially segregated into three groups in a cultivation age-dependent manner. Then, within the same cultivation age group, leaf samples were clustered into four subgroups in a cultivar-dependent manner. The overall prediction accuracy for discrimination of cultivars and cultivation ages was 94.8% in a cross-validation test. These results clearly show that the FT-IR spectra combined with multivariate analysis from ginseng leaves can be applied as an alternative tool for discriminating of ginseng cultivars and cultivation ages. Therefore, we suggest that this result could be used as a rapid and reliable F1 hybrid seed-screening tool for accelerating the conventional breeding of ginseng.

The utility of infrared (IR) spectroscopy for the determination of strawberry ripeness has been successfully demonstrated. Transmission IR spectra were collected using dried liquid extracts from strawberry flesh. The overall IR feature provided fairly noticeable differences, and the ripeness stage was clearly identified using principal component analysis (PCA). Although all of the extracted components contributed to the resulting spectral features for discrimination, the variation of carbohydrate and amide residues played a major role for providing the selective spectral feature. Additionally, NMR spectra were also collected to quantify the concentrations of three small sugars (α-glucose, β-glucose and sucrose) as well as to evaluate the NMR spectral features at each ripeness step. The concentrations of three sugars increased from early to late growth stages. Both IR and NMR spectroscopies were valuable to elucidate the metabolic signatures for the determining of ripeness stage; however, IR spectroscopy could be more advantageous when fast and high throughput analysis is essential.

Root explants excised from carnation plants maintained in vitro formed off-white, friable calluses after three weeks of culture on Murashige and Skoog (MS) medium supplemented with 1 mg l−1thidiazuron (TDZ) and 1 mg l−1α-naphthalaneacetic acid (NAA). These calluses were subsequently transferred to MS basal medium where, after an additional four weeks of culture, approximately 50% of the calluses formed somatic embryos. However, calluses formed on root explants that had been cultured on MS medium supplemented with 2,4-dichlorophenoxyacetic acid did not produce somatic embryos upon transfer to MS basal medium. Somatic embryos developed into plantlets and subsequently were grown to maturity. These results indicate that root explants have a high competence for somatic embryogenesis in carnation.

Abstract Culture conditions for high frequency plant regeneration via somatic embryogenesis and from cell suspension cultures of Pinellia tripartita are described. Leaf and petiole explants formed embryogenic cultures at frequencies of 36.8% and 26.7%, respectively, on Murashige and Skoog (MS) medium supplemented with 1.33? µ M 6-benzyladenine (BA) and 10.74? µ M a -naphthaleneacetic acid (NAA). However, leaf and petiole explants did not form embryogenic cultures on MS medium with various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) as the sole growth regulator. Leaf-derived embryogenic cultures were transferred to MS medium with 4.52? µ M 2,4-D and were subcultured at 4-week intervals. Cell suspensions were established from subcultured embryogenic cultures using liquid MS medium with 4.52? µ M 2,4-D. Upon plating onto MS basal medium, =70% of cell aggregates gave rise to somatic embryos and later plantlets. Regenerated plantlets were transplanted to potting soil and developed to maturity at a frequency of =90% in a growth chamber.

Hypocotyl segments and zygotic embryos of coriander formed embryogenic calli at frequencies of up to 75% when cultured on MS medium supplemented with 1 mgl-1 2,4-D. Calli were transferred to MS liquid medium with 1 mgl-1 2,4-D to initiate cell suspension cultures. Embryogenic cells became finely dispersible in the medium as the subculture proceeded. Cultures were transferred to a nitrogen compound enriched liquid MS medium containing 2% sucrose and 0.1 mgl-1 2,4-D, and cultured two weeks before plating on MS basal medium. Approximately 75% of cell aggregates (1 to two mm in diameter) underwent development into globular to cotyledonary somatic embryos after two weeks of plating. Most of the embryos were subsequently regenerated into plantlets. Regenerants were successfully transplanted to potting soil and grown to maturity in a phytotron.

Duckweeds are small, floating aquatic plants with a number of useful characteristics, including edibility, fast-growing, and a clonal proliferation. Duckweed is also fed to animals as a diet complement because of its high nutritional value. Porcine epidemic diarrhea virus (PEDV) is a major causative agent of fatal diarrhea in piglets and is a serious problem in the hog-raising industry. In this study, we assessed the feasibility of producing a protective antigen for the PEDV spike protein 1 using duckweed, Lemna minor. Stably transformed Lemnawere obtained by co-cultivation with A. tumefaciensEHA105 harboring the PEDV spike protein gene. Transgene integration and expression of the PEDV spike protein 1 gene were confirmed by genomic PCR and RT-PCR and western blot analysis of transgenic Lemna, respectively. This is the first report of the expression of a vaccine antigen against an animal infectious disease in duckweed.