Byung Whan Min

PPI1: A Novel Pathogen-Induced Basic Region-Leucine Zipper (bZIP) Transcription Factor from Pepper

We have isolated a full-length cDNA, PPI1 (pepper-PMMV interaction 1), encoding a novel basic region-leucine zipper (bZIP) DNA-binding protein, from expressed sequence tags differentially expressed in Capsicum chinense P1257284 infected with Pepper mild mottle virus (PMMV). PPI1 encodes a predicted protein of 170 amino acids and contains a putative DNA-binding domain that shares significant amino acid identity with ACGT-binding domains of members of the bZIP DNA-binding protein family. PPI1 was localized in the nucleus and had transcriptional activation activity in yeast. Transcripts of the PPI1 gene were preferentially induced during an incompatible interaction by inoculation with PMMV, Pseudomonas syringae pv. syringae 61, and Xanthomonas campestris pv. vesicatoria race 3. However, the PPII gene was not induced by abiotic stressors that activate the plant defense-signaling pathway. Our data provide the first evidence that a bZIP transcription factor is preferentially induced by pathogen attack, suggesting that PPI1 may play a specific functional role in the regulation of expression of plant defense-related genes.

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

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.

Rapid metabolic discrimination and prediction of dioscin content from African yam tubers using Fourier transform-infrared spectroscopy combined with multivariate analysis.

To determine whether or not FT-IR spectroscopy could be used for taxonomic and metabolic discrimination of African yam lines, tuber samples from African and Asian yam species were subjected to FT-IR. Most remarkable spectral differences between African and Asian yams were found in the 1750-1700 cm(-1) region, polysaccharide (1200-900 cm(-1)) and protein/amide I and II (1700-1500 cm(-1)) regions of FT-IR spectra. A hierarchical dendrogram based on partial least square-discriminant analysis (PLS-DA) of FT-IR data from 7 African yam species show phylogenetic relationship. In addition, the content of dioscin, a steroidal saponin found in yam tuber, was predicted using a PLS regression model with regression coefficient R(2)=0.7208 indicated that prediction model had average accuracy. Thus, considering these results we suggest that FT-IR combined with multivariate analysis could be applied as a novel tool for metabolic evaluation and high-throughput screening of African yam lines with higher content of dioscin.

High frequency plant regeneration from immature ovule-derived embryogenic cell suspension cultures of Chelidonium majus var. asiaticum

Culture conditions for high frequency plant regeneration via somatic embryogenesis in cell suspension cultures of Chelidonium majus var. asiaticum are described. Immature ovules formed embryogenic calluses at a frequency of 40% when cultured on Murashige and Skoog (MS) medium supplemented with 4.52 μM 2,4-dichlorophenoxyacetic acid (2,4-D). The optimum ovule size for embryogenic callus formation ranged from 1 to 1.5 mm in length. Cell suspension cultures were established from embryogenic calluses using MS liquid medium containing 4.52 μM 2,4-D. Upon plating onto MS basal medium, cell aggregates from cell suspension cultures produced somatic embryos which then developed into plantlets. Regenerated plantlets were transplanted to potting soil and grown to maturity in a growth chamber.

Discrimination of Cultivars and Cultivation Origins from the Sepals of Dry Persimmon Using FT-IR Spectroscopy Combined with Multivariate Analysis

This study aimed to establish a rapid system for discriminating the cultivation origins and cultivars of dry persimmons, using metabolite fingerprinting by Fourier transform infrared (FT-IR) spectroscopy combined with multivariate analysis. Whole-cell extracts from the sepals of four Korean cultivars and two different Chinese dry persimmons were subjected to FT-IR spectroscopy. Principle component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) of the FT-IR spectral data successfully discriminated six dry persimmons into two groups depending on their cultivation origins. Principal component loading values showed that the 1750-1420 and regions of the FT-IR spectra were significantly important for the discrimination of cultivation origins. The accuracy of prediction of the cultivation origins and cultivars by PLS regression was 100% (p

Erratum to: Rapid discrimination of F1 hybrid seeds from their parental lines and selection of protein-rich corn lines for silage corn breeding using FT-IR spectroscopy combined by multivariate analysis

This study aims to establish the discrimination of F1 hybrid seeds from their parental lines and rapid selection of proteinrich lines from inbreeding lines of corn using FT-IR spectroscopy combined by multivariate analysis. Eight individual seeds from the maternal and paternal lines of Gwangpyeongok and their F1 progeny seeds were subjected to FT-IR spectroscopy. A total of 176 corn inbreeding lines including commercial corn cultivars were subjected to FT-IR spectroscopy. To establish the prediction model for total protein content from corn seed, 33 corn inbreeding lines out of 176 were randomly selected and total seed protein contents using Bradford assay were examined. PLS-DA (partial least square regression discriminant analysis) could clearly discriminate F1 hybrid seeds from their parental lines. PC (principal component) loading values show that 1,700 – 1,500 cm−1 and 1,200 – 900 cm−1 regions of FT-IR spectra are significantly important for discrimination of corn lines. The prediction model for total protein contents was established by PLS (partial least square regression) algorithm, and its accuracy was confirmed by cross-validation test (R2 = 0.94). After external validation fromexternal 25 corn inbreeding lines, regression coefficient (R2) was 0.78 which indicated that the prediction model had relatively good accuracy. Thus, considering these results we suggest that FT-IR combined with multivariate analysis could be applied as a novel tool for high-throughput screening of F1 hybrid seeds from their parental lines and protein-rich lines for breeding of silage corn cultivar.

Retraction : The Use of Phosphomannose-isomerase as a Selectable Marker to Recover Transgenic Cauliflower

We attempted to establish a new selection marker system from cauliflower without antibiotics or herbicide. This new selection marker system was based on the principle that only the transformed plants could convert mannose to fructose. A transformed plant could then use the fructose as carbon source by using pmi gene that can recognize phosphomannose-isomerase that converts mannose-6-phosphate into fructose-6-phosphate. Agrobacterium tumefaciens LBA4404 contained pNWB-HSP101 vector linked with HSP101. Five days after germination, the heat tolerant gene was inoculated into the cauliflowers hypocotyl. After culturing, selection was performed in MS medium that contained BAP, NAA, 0.4% (w/v) mannose and 2.0% (w/v) sucrose. PCR, Southern blot and Northern blot analyses were performed to determine whether HSP101 gene was inserted in the transformed plant. After acclimation, seeds were successfully collected from the transformed plants in the greenhouse. This is the first report for successful transformation of cauliflower plant using the mannose selection system. Moreover, the stable selection system established in this study could be applied an alternative reducing antibiotics for human health and environmental safety during the genetic transformation of higher plants.