Ectomycorrhizal development in a Pinus thunbergii stand in relation to location on a slope and effect on tree mortality from pine wilt disease

The relationship between ectomycorrhizal development and mortality from pine wilt disease was studied in an artificial Pinus thunbergii Parl. stand on a slope. The development of ectomycorrhizae and the survival of the trees showed the same tendency, which suggests a correlation between mycorrhizal development and resistance to pine wilt disease. The development of pine roots and mycorrhizae was greater in the upper part of the slope. The ratio of mycorrhizae to the total of mycorrhizae and fine taproots was also higher in the upper part of the slope. Tree mortality was clearly biased and more trees survived in the upper part of the slope than in the middle and the lower parts. There was no significant difference between the upper and the lower part of the slope in the number of feeding wounds made by the pine sawyer beetle, which demonstrates the opportunity of infection with this disease. There was no clear correlation between the development of mycorrhizae and the composition of the soil substrate such as total carbon, nitrogen, and phosphorus. The abundant mycorrhizae in the upper part of the slope, which mitigate drought stress, may also have decreased the rate of tree mortality.     

Genotypic variation in polyphenol content of barley grain

The polyphenol content in pearl barley, which is highly correlated to a browning reaction after heat treatment, was investigated using 1,347 cultivated barley varieties (H. vulgare) and two wild accessions (H. vulgare subsp. spontaneum) collected from different areas of the world. The polyphenol content in the cultivated barley shows a wide variation ranging from 0.19 to 0.75 mg/g with a nearly normal frequency distribution. The polyphenol content in the hulless varieties from Japan and Korea was low. On the other hand, the polyphenol content in wild barley was about two times higher than the average value recorded in cultivated barley. Based on HPLC analysis, five lowest-polyphenol content local varieties do not represent proanthocyanidin-free mutants. This revised version was published online in August 2006 with corrections to the Cover Date.     

Potato Virus Y Resistance Gene, Ry chc, Mapped to the Distal End of Potato Chromosome 9

Summary A Japanese leading cultivar ‘Konafubuki’ has an extreme resistance gene Ry _chc to Potato virus Y (PVY) in a simplex fashion. To reduce complexity of the highly heterozygous autotetraploid genome and map the Ry _chc gene, haploid plants were parthenogenetically induced from ‘Konafubuki’. The ratio of 7 resistant: 5 susceptible haploids confirmed the single dominant, simplex genotype of ‘Konafubuki’. A selected resistant haploid 98H20-5 was crossed with a susceptible diploid, resulting in 119 F ₁ plants. Using RFLP and RAPD markers, Ry _chc was mapped to the most distal end of the chromosome 9 where the recovery of recombinant genotypes was extremely reduced in this mapping population possibly due to the linked inferiority factor. The location of Ry _chc is different from those of the other extreme resistance genes to PVY, but possibly resides in one of resistance gene clusters.     

Effect of short-term fasting on hepatic steroid hormone metabolism in cows

In the present study, the effect of 4-day fasting on steroid hormone metabolism in the liver and secretion of LH was examined in cows. Six non pregnant, dry Holstein cows were used. The estrous cycle was synchronized in all cows using CIDR-Ovsynch. Cows were allocated to a control group (n=3) and a fasting group (n=3). In the fasting group, cows were fasted for four days from day -4 to day -1 (day 0=day of 2nd GnRH injection) but otherwise were fed ad libitum. The experiment was repeated in a crossover design after an interval of about one month. The peripheral progesterone (P(4)) concentration in the fasting group was significantly higher than in the control group on day -1 and 0. The peripheral estradiol-17β concentration in the fasting group was also significantly higher than in the control group on day -1 and 0. The portal vein P(4) concentration in the fasting group was significantly higher than in the control group. On day 0, there was no difference in LH secretion between groups. The mean percentages of lipid droplets in liver cells in the fasting group were significantly higher than in the control group on day 0. These results suggest that short-term fasting leads to reduced hepatic steroid hormone metabolism by accumulation of fat in the liver, which causes high peripheral steroid hormone concentrations.     

A maternally inherited DNA marker,descended from Solanum demissum (2n = 6x = 72) to S. tuberosum (2n = 4x = 48)

A Mexican hexaploid wild potato species, Solanum demissum (dms), was only used as a female in previous breeding programs. The resulting clones with dms cytoplasm produced abundant, but non-functional pollen. A 170 bp DNA fragment, named Band 1, was originally detected in the F₁ hybrid between dms and S. tuberosum. In this study, the sequenced region was extended to 1,032 bp; nevertheless, it did not show any homology to known sequences. This extended region harboring Band 1 was, without introns, all transcribed to mRNA and was maternally inherited from dms to S. tuberosum through backcrosses. Three dms accessions, 168 accessions of 38 cultivated and closely related wild species, and 158 varieties and breeding lines were surveyed, which demonstrated that Band 1 was specific to dms and varieties and breeding lines with dms cytoplasm. Thus, Band 1 is a useful marker to distinguish dms cytoplasm, which enables us to design efficient mating combinations in breeding programs.     

Measurement of carbonic anhydrase isozyme VI (CA‐VI) in swine sera,colostrums, saliva,bile, seminal plasma and tissues

Swine secretory carbonic anhydrase VI (CA‐VI) was purified from swine saliva and an antibody to CA‐VI was generated. A specific and sensitive enzyme‐linked immunosorbent assay (ELISA) has been developed for the measurement of swine CA‐VI. The assay can detect as little as 5 ng/mL of swine CA‐VI. Typical standard curves were determined for a range of CA‐VI solutions (7.8 to 500 ng/mL). The coefficients of variation for these solutions were less than 5%. When 500, 250 or 100 ng/mL of swine CA‐VI was added to swine sera, the recoveries were 102.0%, 109.7% and 100.2%, respectively. The concentrations of CA‐VI in the saliva (26.2 ± 30.4 µg/mL), sera (3.3 ± 4.9 ng/mL), bile (153.0 ± 114.0 ng/mL), seminal plasma (124.0 ± 39.0 ng/mL) and parotid gland (441.3 ± 90.0 µg/g wet tissue), submaxillary gland (88.1 ± 124.4 µg/g wet tissue), sublingual gland (58.6 ± 24.6 µg/g wet tissue) and gallbladder (2.4 ± 1.3 µg/1g wet tissue) were determined by ELISA. The concentration of CA‐VI in colostrum was 163.3 ± 101.4 ng/mL and did not decrease within 10 days following parturition. An immunohistochemical reaction to anti‐CA‐VI antiserum was observed in the columnar epithelial cells lining the gallbladder. These data suggest that secretory CA‐VI plays various roles in pH regulation and the maintenance of ion and fluid balance.     

Influence of Cordyceps sinensis on cytokine profile of dendritic cells in chronic obstructive pulmonary rat model

AIM: To investigate the effect of Cordyceps sinensis (CS) on dendritic cells (DCs) in the rat model of chronic obstructive pulmonary disease (COPD). METHODS: Eighteen Sprague-Dawley male rats were randomly divided into 3 groups: control group, COPD group and CS group.The rats in the latter 2 groups were exposed to cigarette smoking for 8 weeks with (CS group) or without (COPD group) CS treatment. The rats in control group were maintained under normal condition. After 8 weeks,the histological changes of the right lung were observed under microscope. The DCs from the 3 groups were harvested and the supernatants of DCs were analyzed for the levels of TNF-α and IL-12 p70 by commercially available ELISA kit. The DCs were then washed and cocultured in vitro with autologous T cells purified by a nylon cotton column. The supernatants of DCs-T coculture were collected after 72 h incubation, and analyzed for the levels of interleukin-5 (IL-5) and interferon-γ (IFN-γ) by ELISA. RESULTS: Analysis of the rat lung parenchyma revealed a significant decrease in the mean alveolar number, an indicator of alveolar density, in COPD group (38±16) and CS group (48±9) in comparison with control group (62±8). The mean alveolar number tended to be increased in CS group than that in COPD group, although this difference did not achieve statistical significance (P>0.05). The concentrations of TNF-α and IL-12 p70 in the culture supernatants of DCs and IFN-γ in the supernatants of DCs-T cocluture were up-regulated in CS group as compared with those in COPD group and control group (P<0.05). The level of IL-5 in the DCs-T coculture supernatants of the 3 groups did not show differences with statistical significance (P>0.05). CONCLUSION: The therapeutic effects of CS on COPD rats may be related to modulation of Th1 and Th2 cell functions. This effect is probably mediated through IL-12 p70 produced by DCs and Th1 cytokine IFN-γ produced by autologous T cells.     

Concentrations of ketone body and antidiuretic hormone in cerebrospinal fluid in response to the intra‐ruminal administration of butyrate in suckling calves

The aim of the present study was to elucidate the mechanism by which ketone bodies increase antidiuretic hormone (ADH) secretion. Four male Holstein calves (5 weeks of age) were utilized. Four levels of butyrate (0 g, 11 g, 22 g and 44 g) were administrated intra‐ruminally in a 4 × 4 Latin square design and cerebrospinal fluid (CSF, six‐position lumbar puncture), blood plasma and urine were collected. The concentration of total plasma and CSF protein was 5.5–5.6 g/dL and 27.5–28.3 mg/dL, respectively. CSF concentrations of a specific ketone body, 3‐hydroxybutyric acid, were significantly higher in the 22 g and 44 g butyrate groups than in the control group. CSF concentrations of ADH in the 11 g and 44 g butyrate groups were significantly higher than in the control group. Plasma concentration of 3‐hydroxybutyric acid was increased by intraruminal administration of butyrate within 15 min in a dose‐dependent manner, and it was higher in the 22 g and 44 g butyrate group than in the control group from 15 min to 4 h. With the exception of the 11 g butyrate group, plasma concentrations of ADH also increased in response to butyrate treatment, and it was higher in the 44 g butyrate group than in the 22 g butyrate group from 15 min to 1.5 h. The duration of the elevated plasma concentrations of ADH was shorter than that of the plasma concentration of 3‐hydroxybutyric acid. The relationship between the plasma concentrations of ADH and 3‐hydroxybutyric acid was statistically significant but the correlation between the two concentrations was not high. Butyrate treatment elevated the plasma concentration of ADH and also resulted in reduced urine volume and increased urine osmolality. Haematocrit (Ht) values, and the osmolality of CSF and plasma were not different among the groups. Our results suggested that the increased ADH secretion observed in suckling calves fed dry feeds was caused by butyrate‐derived ketone body that crossed the blood‐brain barrier rapidly.     

Nosological study of Borna disease virus infection in race horses.

To investigate the prevalence of diseases in the Borna disease virus (BDV) antibody positive race horses, we undertook seroepidemiological studies of BDV infection on 125 culled race horses in Hokkaido, Japan. The serological study disclosed the presence of antibodies only to BDV-p40 or -p24 in 19.2% (24/125) and 3.2% (4/125) of culled horses, respectively. Antibodies to both BDV-p40 and -p24 were found in 24.0% (30/125) of these horses. Of particular note was the finding that locomotorium disorders were detectable at a significantly higher rate in BDV antibody positive horses than that in the seronegative horses. These results imply that BDV infection may possibly contribute to an increase in the incidence rate of locomotorium disorders in race horses.