Discrimination of cultivation ages and cultivars of ginseng leaves using Fourier transform infrared spectroscopy combined with multivariate analysis

AbstractTo 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

Development of an expression system using the heat shock protein 70 promoter in the red macroalga, Porphyra tenera

Porphyra is a commercially valuable source of food and drugs, and represents an important model organism for algal research. However, genetic research on P. tenera has been limited due to lack of a heterologous gene expression system. In the present study, we isolated a native promoter, the PtHSP70 promoter, for efficient expression of foreign genes in this organism. This promoter lies approximately 1 kb upstream of the coding sequence for Heat Shock Protein 70 (HSP70) and was isolated using adapter-mediated genomic PCR. Promoter activity was evaluated using the synthetic GUS gene (PyGUS) with optimized codons for Porphyra yezoensis. Interestingly, the PtHSP70 promoter allowed equivalent expression of PyGUS in both P. tenera and P. yezoensis, whereas the GAPDH promoter from P. yezoensis was not fully functional in P. tenera. These data suggest that the PtHSP70 promoter has a more conserved regulatory mechanism than the PyGAPDH promoter between these species. We also established an efficient transient transformation system for P. tenera by evaluating various transformation parameters such as quantity of gold particles, pressure of helium and vacuum, developmental stages of leafy gametophytes, and target distance. Under the optimal conditions of transient transformation, the frequency of GUS expression was determined by histochemical staining to be 30-50 cells per bombardment. Therefore, the new transient transformation system using the PtHSP70 promoter can be used for foreign gene expression in P. tenera, which may advance the development of P. tenera as a model organism

CHRK1, a Chitinase-Related Receptor-Like Kinase in Tobacco

A cDNA encoding a chitinase-related receptor-like kinase, designated CHRK1, was isolated from tobacco (Nicotiana tabacum). The C-terminal kinase domain (KD) of CHRK1 contained all of the conserved amino acids of serine/threonine protein kinases. The putative extracellular domain was closely related to the class V chitinase of tobacco and to microbial chitinases. CHRK1 mRNA accumulation was strongly stimulated by infection with fungal pathogen and tobacco mosaic virus. Amino acid-sequence analysis revealed that the chitinase-like domain of CHRK1 lacked the essential glutamic acid residue required for chitinase activity. The recombinant chitinase-like domain did not show any catalytic activity for either oligomeric or polymeric chitin substrates. The recombinant KD of CHRK1 exhibited autophosphorylation, but the mutant KD with a mutation in the essential ATP-binding site did not, suggesting that CHRK1 encoded a functional kinase. CHRK1 was detected in membrane fractions of tobacco BY2 cells. Furthermore, CHRK1-GFP fusion protein was localized in plasma membranes when it was expressed in animal cells. This is the first report of a new type of receptor-like kinase containing a chitinase-like sequence in the putative extracellular domain

Mass propagation of microtubers from suspension cultures of Pinellia ternata cells and quantitative analysis of succinic acid in Pinellia tubers

The conditions for efficient tuber production from suspension cultures of Pinellia ternata cells which is one of medicinal herbs were established and succinic acid in tubers propagated in vitro was determined. Leaf explants formed white nodular structures and off-white calluses at a frequency of 90.6 % when cultured on Murashige and Skoog medium supplemented with 0.54 μM α-naphthaleneacetic acid (NAA); however, this frequency declined substantially with increasing NAA concentration, up to 16.2 μM, at which the frequency reached zero percent. In combination treatments with 4.44 μM 6-benzyladenine (BA) and NAA, however, the frequency of white nodular structure and off-white callus formation from leaf explants did not decrease, even at 16.2 μM NAA. Suspension cultures of P. ternata cells were established from leaf-derived off-white calluses in MS liquid medium containing 5.4 μM NAA and 4.44 μM BA. Upon plating onto MS basal medium, over 90 % of cell aggregates gave rise to microtubers and developed into plantlets. Regenerated plantlets were transplanted in potting soil and grown to maturity in a growth chamber, with a survival rate of >90 %. The highest succinic acid content in suspension culture-derived microtubers was 45 g/kg of extract. Compared with wild P. ternata medicinal tubers, the succinic acid content was very similar. The in vitro P. ternata microtuber proliferation system established in this study is thus an efficient alternative for the mass production of medicinal tubers. © 2015, Korean Society for Plant Biotechnology and Springer Japan.