Determination of top-dressing for rice in the field by the detection of asparagine

It is well known that an increase of and better grain can be obtained by the application of an adequate amount of quick-acting nitrogen fertilizers such as ammonium sulphate, thirty to twenty five days before heading, and this is a common practice of top-dressing, being called “Hogoe” in Japanese. It is also well known that excess of nitrogen supplied at this time makes plants weak against mechanical injury, insects and disease. For the application of “Hogoe”, therefore, an accurate diagnosis of the nitrogen nutrient condition of rice is required. In a series of investigations on the nitrogen metabolism, the author found that asparagine appeared in parallel with the increase of nitrogen concentration in rice plants, and considered that the detection of asparagine would be a good indicator for assessing the nitrogen requirement of rice lantst^l).     

Absorption of Radioactive Strontium by Soil,Especially in Relation to Native Calcium

Since it has been well known that radioactive strontium, among the fission nuclides, is particularly important in respect to the potential biological radiation hazard, much attention has been given in recent years to the study on its behaviour in soil and plant. The experiments described herein were conducted in order to elucidate some of the features of carrier-free radioactive strontium added to soils especially in connection with native calcium.     

Further study on iodine toxicity in relation to “Reclamation Akagare” disease of lowland rice

On the basis of the study on iodine behaviour in soil-plant system and other related informations. Tensho and Yeh(1,2,5) have suggested and demonstrated that the iodine toxicity is responsible for the “Reclamation Akagare” disease of lowland rice. Some additional evidences for this view will be presented. which were obtained particularly in connection with field studies on local problem.     

Comparison of Salmonella enterica serovar Abortusequi isolates of equine origin by pulsed-field gel electrophoresis and fluorescent amplified-fragment length polymorphism fingerprinting

Equine paratyphoid is caused by Salmonella enterica serovar Abortusequi, and manifests mainly as abortion in the mare. We compared S. Abortusequi strains isolated in Japan and other countries using pulsed-field gel electrophoresis (PFGE) and fluorescent amplified-fragment length polymorphism (FAFLP) analysis. PFGE analysis of S. Abortusequi strains gave 21-27 fragments ranging in size from 33 to 602kb. Although two PFGE profiles were observed among the 20 S. Abortusequi isolates in Japan, the restriction fragments originating from the chromosome were common between the two profiles. The similarity index of the two profiles was 90.9%, while those between Japanese and five other S. Abortusequi strains were 29.8-37.5%. On the other hand, FAFLP analysis of S. Abortusequi strains generated 64-67 amplified fragments ranging in size from 100 to 400bp. One polymorphic fragment was observed among the 20 S. Abortusequi isolates in Japan. These data indicate the close relation of this agent in Japan. S. Abortusequi strains sharing a common ancestry might have been conserved in Japan.     

Expression of Glucocorticoid Receptor α and Its Regulation in the Bovine Endometrium: Possible Role in Cyclic Prostaglandin F2α Production

Cortisol (Cr), the most important glucocorticoid (GC), is well known to suppress uterine prostaglandin F2α (PGF) production. However, the details of the regulatory mechanisms controlling the cyclic changes in endometrial PGF production remain unclear. Here we investigated the expression of the GC receptor (GC-Rα), the actions of cortisol throughout the estrous cycle and the regulatory mechanism of GC-Rα in the bovine endometrium. The levels of GC-Rα protein were greater at the mid-luteal stage (Days 8–12) than at the other stages. Cr more strongly suppressed PGF production at the mid-luteal stage than at the follicular stage. GC-Rα expression was increased by progesterone (P4) but decreased by estradiol-17β (E2) in cultured endometrial stromal cells. The overall results suggest that ovarian steroid hormones control the cyclic changes in endometrial PGF production by regulating GC-Rα expression in bovine endometrial stromal cells.     

Evaluation of the PATHFAST Chemiluminescent Enzyme Immunoassay for Measuring Progesterone in Whole Blood and Serum of Mares

Evaluation of a new chemiluminescent enzyme immunoassay, the PATHFAST assay system (PATHFAST), for measurement of circulating progesterone in mares was performed. Five mares at the mid-luteal stage were administrated a single i.m. injection of prostaglandin F2α analog (PGF2α; cloprostenol 250 μg/ml), and then blood samples were collected from the jugular vein at 0, 15, 30 and 45 min, at one-hour intervals until 24 and at 48 hr via a catheter in the jugular vein. To monitor the physiological changes in circulating progesterone in mares after induced luteolysis, concentrations of progesterone in whole blood and serum samples were measured by PATHFAST. In addition, concentrations of progesterone in serum samples measured by PATHFAST were compared with those measured by radioimmunoassay (RIA) and enzyme immunoassay (EIA). Using PATHFAST, the serum concentrations of progesterone in mares correlated highly with those of whole blood samples (r=0.9672, n=88). The serum concentrations of progesterone as measured by PATHFAST correlated well with RIA (r=0.9654, n=88) and EIA (r=0.9323, n=112). An abrupt decline in circulating progesterone in whole blood samples was observed within 2 hr (50%), followed by a gradual decline until 48 hr later. The results for progesterone in whole blood samples correlated highly with those in serum samples, and the declining pattern paralleled that of the serum samples. These results demonstrated that PATHFAST is useful in the equine clinic as an accurate diagnostic tool for rapid assay of progesterone within 26 min, using unextracted whole blood.     

Resistance to anthracnose is decreased by tissue culture but increased with longer acclimation in the resistant strawberry cultivar

Inoculation of tissue-cultured plants of strawberry cultivar Ichigochukanbohon-Nou2gou (Nou-2) with the anthracnose pathogen (Glomerella cingulata) results in wilting and plant death, whereas inoculation of strawberry runners grown in greenhouses results in leaf spots, not wilting or death. When tissue-cultured Nou-2 plants were acclimated for 3, 9 or 15 days, plant resistance to anthracnose increased as the acclimation period increased, suggesting that the resistance of Nou-2 may be induced by external factors. To clarify the mechanisms of resistance, we used cDNA microarray analyses to compare gene expressions among tissue-cultured and acclimated plants of the resistant cultivar Nou-2 and the susceptible cultivar Tochiotome. As a result, we identified 18 cDNA clones that were upregulated during acclimation in Nou-2 but not in Tochiotome. In a real-time RT-PCR of the 18 clones, the expression levels of three were significantly higher in acclimated plants of Nou-2. Two of the three clones showed close homology to enzymes related to flavonoid biosynthesis, i.e., leucoanthocyanidin dioxygenase (LDOX, ANS) and UDP-glucosyltransferase, putative (3-GT). The clones spotted onto the cDNA microarrays were rechecked, and 23 nonredundant cDNA clones of 13 enzymes were estimated to be flavonoid biosynthetic enzymes. Most of these clones were upregulated by acclimation in Nou-2.     

Quantification of phosphatidic acid in foodstuffs using a thin-layer-chromatography-imaging technique

Apical application of lysophosphatidic acid (LPA), a growth-factor-like phospholipid, was shown to prevent or restore gastrointestinal (GI) disorders, such as diarrhea and stomach ulcer, in experimental animals. Because LPA is formed from phosphatidic acid (PA) by the activity of digestive phospholipase A(2), PA is a potential component for dietary treatment of such GI disorders. Here, we quantified PA contained in 38 foodstuffs and 3 herbs by a thin-layer-chromatography-imaging technique. Vegetables belonging to Brassicaceae, such as cabbage leaves (700 nmol/g of wet weight) and Japanese radish leaves (570 nmol/g), contained higher amounts of PA than other foodstuffs. Amounts of PA in fruits, cereals, and starchy root vegetables were below 300 nmol/g. Animal foodstuffs contained low amounts of PA (<60 nmol/g). Interestingly, leaves of Mallotus japonicas, a Japanese edible herb used for treatment of stomach ulcer, had the highest PA (1410 nmol/g) among those examined. The data shown here will be useful for the development of dietary treatment for a damaged GI tract.     

What is the optimal density of larval seeding in Acropora corals?

In situ larval seeding is a low-cost technique that is currently under development for the large-scale restoration of coral populations. One problem that still needs to be solved is the preparation of coral larvae for seeding, i.e., how many larvae are required to restore a certain area? In this study, we focused on the relationship between the numbers of larvae, settlers, and survivors for three?months post-settlement to determine the optimal larval seeding density. A comparison of three different larval densities (low, middle, and high) indicated that the number of settlers was proportional to the larval density, suggesting that settler density is determined by the number of larvae supplied. However, the survival rate of settlers on high-density plates was much lower than the corresponding rates on low- or middle-density plates during the first month after settlement. Moreover, most of the seeded corals had not survived on the low-density plates at three?months after settlement. Therefore, the middle larval density (i.e., 5000?larvae?m^?2) appears to be optimal for seeding on grid plates.