SUMMARYNitrogen-fixing symbiosis between legumes and rhizobia is initiated by the recognition of rhizobial Nod factors (NFs) by host plants. NFs are diversely modified derivatives of chitin oligosaccharide, a fungal elicitor that induces defense responses in plants. Recent evidence has shown that both NFs and chitin elicitors are recognized by structurally related LysM receptor kinases. Transcriptome analyses of Lotus japonicus roots indicated that NFs not only activate symbiosis genes but also transiently activate defense-related genes through NF receptors. Conversely, chitin oligosaccharides were able to activate symbiosis genes independently of NF receptors. Analyses using chimeric genes consisting of the LysM receptor domain of a Lotus japonicus NF receptor, NFR1, and the kinase domain of an Arabidopsis chitin receptor, CERK1, demonstrated that substitution of a portion of the aEF helix in CERK1 with the amino acid sequence YAQ from the corresponding region of NFR1 enables L. japonicus nfr1 mutants to establish symbiosis with Mesorhizobium loti. We also showed that the kinase domains of two Lotus japonicus LysM receptor kinases, Lys6 and Lys7, which also possess the YAQ sequence, suppress the symbiotic defect of nfr1. These results strongly suggest that, in addition to adaptation of extracellular LysM domains to NFs, limited alterations in the kinase domain of chitin receptors have played a crucial role in shifting the intracellular signaling to symbiosis from defense responses, thus constituting one of the key genetic events in the evolution of root nodule symbiosis in legume plants.
The recurrence rate after thoracoscopic bullectomy with fleece-coated fibrin glue was significantly lowered and we consider this procedure to be the treatment of choice for the management of spontaneous pneumothorax.
Hairy root cultures of a model legume, Lotus japonicus, were established to characterize two heterologous cDNAs encoding enzymes involved in isoflavone biosynthesis, i.e. licorice 2-hydroxyisoflavanone synthase (IFS) and soybean 2-hydroxyisoflavanone dehydratase (HID) catalyzing sequential reactions to yield isoflavones. While the control and the IFS overexpressor did not accumulate detectable isoflavones, the HID overexpressors did accumulate daidzein and genistein, showing that HID is a critical determinant of isoflavone productivity. Production of coumestrol in all the genotypes and isoliquiritigenin/liquiritigenin in IFS + HID-overexpressing lines was also noted. These results provide insight into the regulatory mechanism that controls isoflavonoid biosynthesis.
Blood and urine samples were analyzed for ethanol, acetaldehyde and acetate during alcohol oxidation in Japanese men by head space gas chromatography, following the consumption of 16 ml/kg of beer during a 20 min period. The maximum level of blood/urine ethanol was found to be 15-17 mM (20-22 mM), while that of acetaldehyde in a flusher and in non-flushers was 20 microM (52 microM) and 2-5 microM (10-13 microM), respectively. Acetate levels in these groups ranged from 0.2 mM (0.1 mM) to 0.8 mM (1.0 mM). Blood ethanol levels were dose dependent, whereas acetaldehyde and acetate levels reflected individual metabolic rates. The relative concentrations of ethanol and acetaldehyde in blood and that of acetate in alcohol metabolism could be summarized as follows: 7500 (15 mM): 1-3 (2-5 microM); 250-400 (0.5-0.8 mM) for non-flushers; and 7500 (15 mM): 5-10 (10-20 microM): 250-400 (0.5-0.8 mM) for a flusher.
Chronic expanding hematoma of the thorax may occur after thoracic surgery and a tuberculosis infection; however, considering the risk of massive bleeding during surgery, the decision to perform surgery should be made with extreme care.
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