Background : Dioscorea quinqueloba(DQ) is a medicinal herb that is used as an alternative therapy for cardiovascular disease and various medical conditions. The objective of this study was to characterize the antioxidant activities of DQ. Methods and Results : The samples were extracted with Distilled water and analyzed for total flavonoid contents, polyphenol contents, DPPH radical scavenging activity, and ABTS radical scavenging activity. H9c2 cardiomyoblast cells were subjected to H2O2, to study the protective effect of DQ on cell viability, and ROS production. The total amounts of polyphenols and flavonoids, which indicate the antioxidant capabillity of water extracts from DQ were 27.21mg/g and 22.95mg/g, respectively. The DQ water extract showed highest antioxidant activity by DPPH and ABTS scavenging activities. The DQ water extract was protected cells against H₂O₂-induced cell death without any cytotoxicity, as determined by the MTT assay. The DQ water extract also was inhibiting production of intracellular ROS. Conclusion : These observations suggest that DQ can use potentially good natural antioxidant in daily life for possible health benefits.

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.

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.

Compared to wide ranges of genetic variation of natural populations, very limited Miscanthus cultivar has been released. This study was the first report on the development of Miscanthus cultivar by means of radiation breeding. Seeds of M. sinensis were initially exposed to gamma rays of 250 Gy for 24 h, generated from a 60Co gamma-irradiator. The irradiated seeds were sown and then the highly tiller-producing mutants were selected for this study. Biomass-related parameters including tiller number, plant height, stem diameter, and leaf number were measured. Ploidy level and internal transcribed spacer (ITS) were investigated to characterize the mutants compared to wild type (WT) Miscanthus. Plant height and tiller number were negatively related, where multi-tillering mutants were relatively short after 4 month growth. However stem diameter and leaf number were greater in mutants. All the materials used in this study were diploid, implying that the mutants with greater tiller numbers and stem diameter were not likely related to polyploidization. Based on the sequence of ITS regions, the mutants demonstrated base changes from the gamma irradiation where G+C content (%) was decreased in the ITS1, but increased in ITS2 when compared to WT sequence. ITS2 region was more variable than in ITS1 in the mutants, which collectively allows identification of the mutants from WT. Those mutants having enhanced tillers and allelic variations might be used as breeding materials for enhanced biomass-producing Miscanthus cultivars.

Italian Ryegrass, also called annual ryegrass, is a high productivity and feed value, and an upright grass that behaves like a biennial or short-lived perennial. It grows vigorously in winter and early spring. Italian ryegrass and a related species, perennial ryegrass, Lolium perenne, are the two common weedy ryegrassses. Italian ryegrass and perennial ryegrass can hybridize, resulting in offspring that are difficult to identify as either species. Ryegrasses are cultivated for turf and forage. Sometimes Italian ryegrass is grown as cover crop. It has the potential to produce high yields and, with proper management, can be high quality with good animal performance. To develop of a high quality, productivity and early variety, 11 varieties were in the seven different irradiation conditions (0Gy, 100Gy, 200Gy, 300Gy, 400Gy, 500Gy, 1,000Gy) and examined growth and germination characters of each plant as like plant height, number of tillers. As a increase of irradiation, germination rate of 11 Italian ryegrass varieties are somewhat reduced.

TILLING (Targeting Induced local Lesions IN Genomes) is known to be an excellent methodology for reverse genetics approach. About 15,000 M3 TILLING lines have been developed after gamma-ray irradiation to the rice seeds of Donganbye. In order to assess genetic diversity of the TILLING population. we have employed a multiple dominant marker technique, such as AFLP. A total of 96 (0.64%) lines including Dongganbye were randomly selected and their genetic diversity was assessed on the basis of AFLP marker polymorphism by using 5 primer combinations. An average of 100.4 loci with a range of 97 to 106 were detected by using the primer combinations, resulting in 173 (34.6%) polymorphic loci among 96 lines. A broad range of similarities with 80% to 96% was evidenced between Donganbye and each of 96 TILLING lines, reflecting genetic diversity of the TILLING population. About 30 polymorphic loci have been cloned and their sequences have been blasted against rice whole genome sequences. The sequences evidenced highly significant matches to each of genes including exons and introns, upstream sequences and downstream of genes, and intergeneic sequences. Therefore, the TILLING rice population would be valuable genetic sources for rice functional genomics.