Catalases CAT1 and CAT3 are not key enzymes in alleviating gamma irradiation-induced DNA damage, H2O2 accumulation, or lipid peroxidation in Arabidopsis thaliana.

Gamma irradiation increased catalase activities at 0.1 kGy and decreased them at 10 kGy in Arabidopsis wild type and catalase-deficient mutants, cat3-1 and cat1 cat3. Irradiation induced DNA damage, H2O2 accumulation, and lipid peroxidation in both mutants as well as the wild type. Thus catalases might not be key enzymes protecting gamma irradiation-induced damage.

Effect of γ irradiation on the fatty acid composition of soybean and soybean oil.

Food irradiation is a form of food processing to extend the shelf life and reduce spoilage of food. We examined the effects of γ radiation on the fatty acid composition, lipid peroxidation level, and antioxidative activity of soybean and soybean oil which both contain a large amount of unsaturated fatty acids. Irradiation at 10 to 80 kGy under aerobic conditions did not markedly change the fatty acid composition of soybean. While 10-kGy irradiation did not markedly affect the fatty acid composition of soybean oil under either aerobic or anaerobic conditions, 40-kGy irradiation considerably altered the fatty acid composition of soybean oil under aerobic conditions, but not under anaerobic conditions. Moreover, 40-kGy irradiation produced a significant amount of trans fatty acids under aerobic conditions, but not under anaerobic conditions. Irradiating soybean oil induced lipid peroxidation and reduced the radical scavenging activity under aerobic conditions, but had no effect under anaerobic conditions. These results indicate that the fatty acid composition of soybean was not markedly affected by radiation at 10 kGy, and that anaerobic conditions reduced the degradation of soybean oil that occurred with high doses of γ radiation.

Allyl isothiocyanate (AITC) induces stomatal closure in Arabidopsis.

Isothiocyanates (ITCs) are degradation products of glucosinolates in crucifer plants and have repellent effect on insects, pathogens and herbivores. In this study, we report that exogenously applied allyl isothiocyanate (AITC) induced stomatal closure in Arabidopsis via production of reactive oxygen species (ROS) and nitric oxide (NO), and elevation of cytosolic Ca(2+) . AITC-induced stomatal closures were partially inhibited by an inhibitor of NADPH oxidase and completely inhibited by glutathione monoethyl ester (GSHmee). AITC-induced stomatal closure and ROS production were examined in abscisic acid (ABA) deficient mutant aba2-2 and methyl jasmonate (MeJA)-deficient mutant aos to elucidate involvement of endogenous ABA and MeJA. Genetic evidences have demonstrated that AITC-induced stomatal closure required MeJA priming but not ABA priming. These results raise the possibility that crucifer plants produce ITCs to induce stomatal closure, leading to suppression of water loss and invasion of fungi through stomata.

Hypoxia-inducible genes encoding small EF-hand proteins in rice and tomato.

Rice has evolved metabolic and morphological adaptations to low-oxygen stress to grow in submerged paddy fields. To characterize the molecular components that mediate the response to hypoxia in rice, we identified low-oxygen stress early response genes by microarray analysis. Among the highly responsive genes, five genes, OsHREF1 to OsHREF5, shared strong homology. They encoded small proteins harboring two EF-hands, typical Ca(2+)-binding motifs. Homologous genes were found in many land plants, including SlHREF in tomato, which is also strongly induced by hypoxia. SlHREF induction was detected in both roots and shoots of tomato plants under hypoxia. With the exception of OsHREF5, OsHREF expression was unaffected by drought, salinity, cold, or osmotic stress. Fluorescent signals of green fluorescent protein-fused OsHREFs were detected in the cytosol and nucleus. Ruthenium red, an inhibitor of intracellular Ca(2+) release, repressed induction of OsHREF1-4 under hypoxia. The HREFs may be related to the Ca(2+) response to hypoxia.

[The Contribution of GMP-grade Hospital Preparation to Translational Research].

Translational research is important for applying the outcomes of basic research studies to practical medical treatments. In exploratory early-phase clinical trials for an innovative therapy, researchers should generally manufacture investigational agents by themselves. To provide investigational agents with safety and high quality in clinical studies, appropriate production management and quality control are essential. In the Department of Pharmacy of Kyoto University Hospital, a manufacturing facility for sterile drugs was established, independent of existing manufacturing facilities. Manuals on production management and quality control were developed according to Good Manufacturing Practices (GMP) for Investigational New Drugs (INDs). Advanced clinical research has been carried out using investigational agents manufactured in our facility. These achievements contribute to both the safety of patients and the reliability of clinical studies. In addition, we are able to do licensing-out of our technique for the manufacture of investigational drugs. In this symposium, we will introduce our GMP grade manufacturing facility for sterile drugs and discuss the role of GMP grade hospital preparation in translational research.