To investigate the suitable growing area for Italian ryegrass (cv. Kowinearly and cv. Green-Call), we survey the different effects of climatic conditions on plant growth in the east (hereafter termed Yeongdong) and west (hereafter termed Yeongseo) of the passes in Gangwon Province. The Italian ryegrass was grown in Gangneung of Yeongdong and Wonju and Chuncheon of Yeongseo. The plants showed growth differences depending on the cultivated regions between before and after wintering. The Italian ryegrass for pre-wintering showed the relatively long length of plant height in Wonju. While, we observed the relatively tall plants for growing- and harvestingperiod after wintering in Gangneung. The increased plant height in Gangneung was closely related to all climatic conditions for the growing period and mean- and lowest-temperature for the harvesting period, respectively. The amount of dry matter was 7,490 kg/ha for Kowinearly and 6,490 kg/ha for Green-Call in Gangneung, which has a higher yield than Chuncheon and Wonju. The relative yield index of dry matter was 77% (Kowinearly) and 78% (Green-Call) in Chuncheon and 84% (Kowinearly) and 71% (Green-Call) in Wonju compared to Gangneung as the standard region. Thus, we suggest that Chuncheon and Wonju are the possible areas for cultivation of Italian ryegrass, considering that Gangneung was the optimum growing area in Gangwon Province.

The field experiment was carried out to evaluate changes of dry matter productivity and feed value of Italian ryegrass and triticale at different growth stages in Wonju from 2018 to 2019. Italian ryegrass and triticale forages were harvested at an interval of seven days from May to June. The dry matter yield of Italian ryegrass with 7,870 kg/ha harvested on May 16 was significantly higher than that harvested on May 3 and May 9. The dry matter yield of triticale with 12,050 kg/ha harvested on June 7 was significantly higher than that harvested from May 3 to May 16. The crude protein yields harvested on May 16 were 890 kg/ha for Italian ryegrass and 1,103 kg/ha for triticale and were significantly higher than those harvested on May 3 and May 9. The total digestible nutrient yield(TDN) of Italian ryegrass with 5,223 kg/ha harvested on May 16 was significantly higher than that harvested on May 3 and May 9. The total digestible nutrient yield of triticale with 8,277 kg/ha harvested on June 7 was significantly higher than that harvested during May, but not different from that harvested after June 7. Considering the dry matter yield, crude protein yield and total digestible nutrient yield, it is suggested that the optimal harvesting times for Italian ryegrass and triticale seem to be May 16 and June 7, respectively.

In recent years, the efficiency and accuracy of QTL analysis for identification of useful traits have been increased by high-throughput genotyping. In a previous study, the genome variation of significant DNA polymorphism was observed in early maturing type rice mutant (EMT) by comparing with that of wild type (WT). For detection of major QTL for flowering time, we constructed a linkage map of 36 InDel- and 6 SNP- markers. In the linkage analysis of F2 plants derived from the cross “WT x EMT”, we have detected one potential QTL region on chromosome 6 by M6-3 marker. Also, the Hd1, which contained the target fragment of M6-3 marker, exhibited the relatively high nonsynonymous substitutions in genes located on chromosomal region from M6-2 to M6-4. To evaluate the reliable allele segregation related to expected Mendelian ratio between M6-3 and its flanking markers, M6-3 marker developed in Hd1 gene exhibited the 1:2:1 ratio as clear monogenic segregation in heterozygous F3 plant. Additionally, we further analyzed the different transcript regulations of OsGI and Hd3a gene related to Hd1 involved in photoperiodic flowering pathway. Although the mRNA levels of Hd1 had no difference between WT and EMT, the Hd3a as downstream effector of Hd1 significantly upregulated in EMT, suggesting that Hd1 gene may become nonfunctional.

Arsenic (As) is accumulated in rice grain due to environmental reasons such as polluted ground water and soil, and As toxicity constitutes a serious threat to human health. However, the accurate information required for understanding As-responsive mechanisms remain mostly unknown in rice. Here, we performed the comparative genome-wide transcriptome analysis between As tolerance type (ATT) rice mutant induced by γ-irradiation and its wild type (WT). As compared to WT after As treatment of 150 ppm, ATT exhibited the phenotypic differences such as vigorous growth in shoots and root hairs, and low accumulation of H2O2 in rice roots. In transcriptome analysis, we found between WT and ATT that As toxicity commonly affected to inhibit gene regulations involved in photosynthesis, mitochondrial electron transport and lipid biosynthesis metabolism. While, many genes associated with cysteine synthesis metabolism considerably up regulated in both As-treated plants. Additionally, we found the potential As tolerance-related genes involved in abiotic stress-responsive mechanism and RNA-protein synthesis for protein degradation and modification. To further analyzes the genetic variations of As-responsive genes, the DNA polymorphic DEGs associated with oxidoreductase significantly distributed in ATT more than in WT.

Asterales are dicotyledonous flowering plants and are one of the Asterid clade, incuding many species as well as Codonopsis and Platycodon. Here, we have determined the complete chloroplast genome sequences of C. lanceolata and P. grandiflorus by using the targeted denovo assembly method of short reads derived from whole genome resequencing. The total lengths of each chloroplast genome sequence are 156,180 bp for C. lanceolata and 155,453 bp for P. grandiflorus. In their chloroplast genomes, 106 genes (75 protein-coding genes, 4 rRNA genes, 23 tRNA genes, and 4 hypothetical chloroplast open reading frames [ycfs]) exhibited the relatively similar positions. Also, 7 protein-coding genes commonly showed to contain introns in both C. lanceolata and P. grandiflorus chloroplast genome, while psaA gene contain intragenic regions only in P. grandiflorus chloroplast genome. In further analysis, we identified the codon usage bias to A or T and found the different simple sequence repeat (SSR) loci of each chloroplast genome (18 SSR loci of C. lanceolata and 16 SSR loci of P. grandiflorus). In the phylogenetic trees based on 72 protein-coding genes, C. lanceolata is more closely related to P. grandiflorus than the other plant species order Asterales. Also, we found the highest sequence diversities of 12 protein-coding genes in small single copy (SSC) region than in the inverted repeat (IRs) and large single copy (LSC) region, and 3 genes such as rpoC2 (LSC region), ndhB (IRs region), and ndhF (SSC region) showed the highest number of segregating sites in each region. Additionally, we developed the molecular markers for phylogenetic applications of C. lanceolata and P. grandiflorus chloroplast genome.

Recently, the increased consumption of mixed-grain flour products have led to improved human health in busy modern life. For this reason, the verification of commercial food authenticity is one of important subjects. The development of DNA techniques such as real-time PCR has led to the increasing efficiency of illegal food product detection. Here, we have developed a comprehensive method for detecting the grain flour of various rice cultivars in commercial food products derived from different plant species. In the genetic variation analysis of different protein coding genes on various chloroplast genomes, we found the high numbers of segregating sites in rpoB and rpoC2 more than in other genes. Thus, we have attempted to develop chloroplast DNA (cpDNA) markers, which were Os_m_rpoB in rpoB, and Os_m1_rpoC2 and Os_m2_rpoC2 in rpoC2. To assess the applicability of three cpDNA markers, we have identified the appropriate statistical measurements of each marker in various mixed-grain flour samples derived from rice cultivars and different plant species by real-time PCR, In addition, the three cpDNA markers successfully applied for detecting of nonexistent rice flour in different commercial food products.

Exposure to ionizing radiation is regarded as a kind of abiotic stresses that can change the expression of genes in living organisms. This study aimed on investigating the variations in gene expressions induced by two different types of irradiations with different doses, which were low linear energy transfer (LET) gamma rays (100, 200, and 400 Gy) and high LET ion-beams (20, 40, and 80 Gy) on rice. RNA sequencing was carried out using the Illumina HiSeq-2500 platform. The average amount of reads were 4.8 Gb per individual, and 5 to 8% of the reads were removed after quality control. More than 90% of the RNA-seq reads were mapped to the rice reference genome sequence (IRGSP-1.0). A total of 247 differentially expressed genes (DEGs) were identified by comparison of the gene expression levels between the wildtype and the irradiated individuals. The 247 DEGs were divided into five modules and 27 intra-modular hub genes were found using the weighted correlation network analysis (WGCNA) method. The MEturquiose module had the most number of genes with 75 related to carbohydrate and small molecule metabolic processes. The co-expression network reconstructed using ARACNE (algorithm for reconstruction of accurate cellular networks) showed specific up- or down-regulation of the genes in each module according to the types and doses of radiation. This study will contribute to understanding the gene expression responses to ionizing irradiation.

In order to select a rice population with useful trait such as arsenic tolerance for crop improvement, we have developed 3000 M7 Targeting Induced Local Lesions IN Genomes (TILLING) lines by gamma ray (GR) irradiation treatment to a rice variety (cv. Donganbyeo). A total of 2 M7 lines exhibited the arsenic (AsV) tolerant phenotype (hereafter, named Arsenic Tolerant TILLING line 1 and 2, and designed as ATT1 and 2), in which the shoots and roots length of ATT lines were significantly longer than those of wild type (WT) during As(V) treatment. To survey the DNA polymorphism of these plants, we conducted the Whole genome resequencing with 10x coverage in ATT lines. By comparative analysis among ATT lines, we have identified the common DNA polymorphism such as 11,817 SNPs (49.83% in ATT1 and 48.35% in ATT2) and 30,618 InDels (86.72% in ATT1 and 86.23% in ATT2). Also, these mutants were showed the close relationships more than WT. To further study the changed amino acids of genes, we commonly identified the 758 genes for non-synonymous SNPs and 249 genes for changed codon InDels. These genes were mainly exhibited the enriched GO functions such as catalytic activity, nucleic acid binding and transferring phosphorus-containing groups. To determine the genes associated with arsenic-related mechanism in DNA polymorphism of ATT lines, we have retrieved the two structurally altered genes (Os11g47870 and Os03g19900) for metalloid As(V) detoxification toward induced genes in response to arsenic treatments by public microarray datasets. We suggest that As(V) tolerant phenotypes of ATT lines are certainly affected by structurally altered genes associated with phosphorus transferring and As(V) detoxification during GR treatment

Low temperature is a major factor restrict to growth and limiting productivity of rice crops. We used a cDNA microarray approach to monitor the expression profile of rice (Oryza sativa) under chilling stress and identified 20 chilling inducible genes in previously study. Ten such genes encoding bHLH, metal transporter and, zinc finger protein with unknown functions showed a significant change in expression under various abiotic stresses. Among them, OsCHI1 (Os07g15460), OsCHI2 (Os02g43660), and OsCHI3 (Os01g61160), were selected for further study. They have structural features such as metal-binding signature sequences in their protein sequences, and OsCHI genes were expressed in root of rice seedling and induced in chilling and salt or drought. Expression of OsCHI1, OsCHI3 and OsCHI2 were targeted to membrane and ER when transiently expressed in tobacco cell, respectively. The Arabidopsis (Arabidopsis thaliana) transgenic plants overexpressing showed increased tolerance to salt and drought stress in the seed germination and root elongation than that of wild type. This comprehensive study provides insight into the biological function of OsCHIs, which may be useful in understanding how rice plants adapt to unfavorable environmental conditions.

We used a microarray dataset that is deposited in the public database to evaluate plant responses to heat stress and selected two genes, OsSHSP1 (Os03g16030) and OsSHSP2 (Os01g04380), that are highly expressed under heat stress in rice. OsSHSP1 and OsSHSP2 gene transcripts were highly induced in response to salt and drought. In addition, OsSHSP1 and OsSHSP2 gene transcripts were induced under ABA and SA. Subcellular localization of proteins of 35S::OsSHSP1 were associated with the cytosol, whereas those of and 35S::OsSHSP2 were associated with the cytosol and nucleus. Heterogeneous overexpression of both genes exhibited higher germination rates than those of wild-type plants under the salt treatment, but not under heat or drought stress. The network of both genes harboring 9 sHSPs as well as at least 13 other chaperone genes might support the idea of a role for sHSPs in the chaperone network. Our findings might provide clues to shed light on the molecular functions of OsSHSP1 and OsSHSP2 in response to abiotic stresses, especially heat stress.

In order to better understand the biological systems that are affected in response to cosmic ray, we conducted the weighted gene co-expression network analysis with module detection method. By using the Pearson’s correlation coefficient value, we were evaluated the complex gene-gene functional interactions between 680 CR-response probes from integrated microarray datasets, which included large-scale transcriptional profiling of 918 microarray samples. These probes were divided into 6 distinct modules that contained 20 enriched function such as oxidoreductase activity, response to stimulus and stress, and hydrolase activity. Especially, module 1 and 2 commonly showed the enriched annotation categories such as oxidoreductase activity, including the enriched cis-regulatory elements known as ROS specific regulator. These results suggest in module1 and 2 that ROS-mediated irradiation response pathway are affected by CR. We found the 243 irradiation-dependent probes, which were exhibited the similarities of differentially expressed patterns in various irradiation microarray datasets, and RT-PCR for confirmations of several irradiation-dependent genes were exhibited the similar expressed patterns in rice by CR, gamma ray and Ion beam treatments. Interestingly, these genes were differentially expressed by non-gravity. Moreover, we were identified the co-regulations between several irradiation-dependent genes and functional interacted genes in the CR-responsive network by various GA treatments such as different conditions of dose and treatment time. These results of network-based analysis might provide a clue to understanding the complex biological system of CR.

Rice is one of the most important food crops in the world, and has been used as model monocots for genetic studies, because of its relatively small genome size. We have previously reported the different functions of several RING (Really Interesting New Gene) proteins to respond the various abiotic stresses. In order to study a regulation of RING proteins in rice under ionizing irradiation such as gamma ray (GA), we have identified the expression patterns of these genes by RT-PCR. We found Gamma-ray induced RING finger protein (OsGRP) gene, which were associated with cytosol by subcellular localization analysis. in vitro ubiquitination assay revealed that OsGRP possess E3 ligase activity. Also, we demonstrate that C196A point mutation in the RING finger domain of OsGRP can have a critical effect to the breakdown of structural integrity in RING constructs. To identify the interaction partners for OsGRP in protein-protein interactions, we found the seven genes interacted with OsGRP by Yeast Two Hybrid method. To examine the GA-influence of interaction partners by RT-PCR, two genes were specifically down-regulated in rice during GA treatment. These interaction partners were identified the reliable interactions and subcellular localizations via BiFC method. Interestingly, five genes associated with plastid, while two down-regulated genes associated with cytosol and plastid. These results of OsGRP based on genetic approach might provide a clue to understanding the GA responsive mechanism in rice.

VitE (tocotrienols and tocopherols) are micronutrients with antioxidant properties synthesized by photosynthetic bacteria and plants that play important roles in animal and human nutrition. A new mutant line, T1001-1, was isolated from in vitro mutagenized population by ionizing radiation and shown to have increased VitE contents. The total VitE content was 26% increased in the T1001-1 mutant seeds compare with cv. Dongan (wild-type). In addition, we showed that the mutant confers retarded seedling growth during the early seedling growth stage in rice. To study the molecular mechanism of VitE biosynthesis, we used the rice microarray to identify genes that are upor down-regulated in T1001-1 mutant. In addition, we identified differentially regulated pathway using MapMan analysis, which provides deep insight into changes in transcript and metabolites. Our results enhanced the transcription of genes involved in starch and lipid metabolism in T1001-1 mutant. To identify the molecular mechanisms of the events involving transcription factors in tocopherol accumulation, we compared the expression patterns of transcription factors. The AP2-EREBP, WRKY, C2H2 transcription factor were up-regulated, whereas the MYB family was down-regulated in T1001-1 mutant. Our results demonstrate change of important transcript in high level of VitE accumulating rice mutant.

Ionizing radiation is known to cause chromosomal alterations such as inversions and deletions and affects gene expression within the plant genome. To monitor the genome-wide transcriptome changes by ionizing radiation, we used rice Affimetrix GeneChip microarray to identify genes that are up- or down regulated by gamma-ray (200 Gy, 60Co source), cosmic-ray and ion beam (40 Gy, 220 MeV carbon ion). The overall expression patterns between gamma-ray and ion beam were similar but cosmic-ray was regulated differently. Combined results from all 3 radiations identified 27 up-regulated genes and 188 down regulated genes. These results mean the induction of similar mechanism changes in treatments of gamma ray and ion beam. However the different expression in treatment of cosmic-ray might be due to the other environmental conditions. Among the commonly up- or down- regulated genes, we chose highly up- or down- regulated several genes and confirmed its regulation in response to ionizing radiation exposure by RT-PCR analysis. Moreover, we showed that specific co-expression networks of candidate radio marker genes by ARACNE algorithm. Our results present profiles of gene expression related to different ionizing radiation and marker gene to predict sensitivity to ionizing radiation, such as GS (glutelin subunit) and FBX322.

The application of next generation sequencing technologies allows us to discover the high levels of DNA polymorphism throughout a genome, e.g., single nucleotide polymorphisms (SNPs), and insertions and deletions (InDels). We performed whole-genome resequencing of a Korean rice cultivar (cv. Donganbyeo) and then obtained the sequences of covered 366,042,872 bp (96.63%) with average mapped read depth of 34.17 on 382,788,128 bp of the Japanese cultivar genome (cv. Nipponbare). We characterized the polymorphisms of 173,711 SNPs, 295,334 insertions and 40,642 deletions based on the comparison of both genomes. About 11.5% and 17.8% of the annotated total SNPs were presented in the regions of 1kb upstreams and genes, respectively. The annotated InDels in gene regions were similar with 15.5% insertion (4,588) and 15.9% (5,100) deletions, but not in 1kb upstream regions with 9.0% insertion (2,662) and 14.3% deletions (5,100). In addition, the Korea rice genome sequences were mapped on individual chromosome, resulted that SNPs were shown with different frequencies from each chromosome. The InDels distributions on individual chromosomes exhibited similar pattern as compared to those of SNPs. Some gene families such as NB-ARC (NB-LRR), F-box, RLK (serine/threonine protein kinase) and Zinc-finger (RING) for SNPs occurred the similar pattern with those of Arabidopsis. These results might be useful for better understanding the genome structure and genetic diversity of the Korean rice cultivars.