Treatment of cattle with DNA-encoded Flt3L and GM-CSF prior to immunization with Theileria parva candidate vaccine antigens induces CD4 and CD8 T cell IFN-γ responses but not CTL responses

Theileria parva antigens recognized by cytotoxic T lymphocytes (CTLs) are prime vaccine candidates against East Coast fever in cattle. A strategy for enhancing induction of parasite-specific T cell responses by increasing recruitment and activation of dendritic cells (DCs) at the immunization site by administration of bovine Flt3L and GM-CSF prior to inoculation with DNA vaccine constructs and MVA boost was evaluated. Analysis of immune responses showed induction of significant T. parva-specific proliferation, and IFN-γ-secreting CD4(+) and CD8(+) T cell responses in immunized cattle. However, antigen-specific CTLs were not detected. Following lethal challenge, 5/12 immunized cattle survived by day 21, whereas all the negative controls had to be euthanized due to severe disease, indicating a protective effect of the vaccine (p<0.05). The study demonstrated the potential of this technology to elicit significant MHC class II and class I restricted IFN-γ-secreting CD4(+) and CD8(+) T cells to defined vaccine candidate antigens in a natural host, but also underscores the need to improve strategies for eliciting protective CTL responses.     

CHANGES IN FOLIAR AMMONIUM CONCENTRATIONS IN SUBSTRATE-GROWN STRAWBERRY

Strawberries (Fragaria × ananassa Duch. cv. Nyoho) grown in peat-based substrate often suffer interveinal chlorosis in their immature leaves 10–20 d after planting. Based on our previous results and observations from growing practice, we hypothesized that the cause of this phenomenon could be due to drastic changes in plant nitrogen (N) nutrition in strawberries just after planting into peat bags. To determine optimal sampling time, diurnal variations in foliar ammonium (NH₄)-N concentration were evaluated under greenhouse conditions. Results showed a broadly similar pattern of diurnal variation, with the rates increasing to a maximum at midday and decreasing steadily during the second-half of the light period. However, foliar NH₄-N concentration was higher under sunny than under cloudy or shaded light conditions. In the second part of this study, changes in foliar NH₄-N and in nitrate (NO₃)-N in petioles in relation to the occurrence of interveinal chlorosis were investigated. When the plants were supplied with 30 (control) or 50% ‘Ohtsuka A’ nutrient solution for two weeks after planting, foliar NH₄-N concentrations increased earlier than petiole NO₃-N concentrations, and reached their peak 8 and 10 days after planting in 50% (1.90 μmol g^?1 FW) and 30% (1.78 μmol g^?1 FW) treatment respectively. Interveinal chlorosis was observed in immature leaves in 50% treatment about 10 days after planting while there was no chlorotic symptom in control treatment. The absence of interveinal chlorosis in immature leaves in control plants, led to the conclusion that a high leaf NH₄-N concentration and related accumulation of NH₄-N play an important role in triggering interveinal chlorosis.     

Uronic acid in humus

Introduction

Uronic acids are aldehydic sugar acids. In nature, they are composed mainly of d-glucuronic acid and d-galacturonic acid and scarcely of dmannuronic acid.     

Low pH and aluminum tolerance of Bradyrhizobium strains isolated from acid soils in Indonesia

Sixty-seven strains of Bradyrhizobium isolated from soybean plants growing on acid soils in West Java and Sumatra, Indonesia, were examined for the effect of the pH and aluminum concentration on their growth in nutrient media, compared with 61 strains of Bradyrhizobium from soils in Japan. The results in this study indicated that the indigenous population of Bradyrhizobium in the soils of Indonesia showed a large difference in acid- and Al-tolerance from that of Japan. Eighty-five and 48% of the isolates from Japanese soils and Indonesian soils, respectively, were unable to grow in YEM broth at pH below 4.5. The acid-tolerance was correlated with AI-tolerance of the isolates on YEM agar plates at pH 4.4. Seventy-five percent of the isolates that grew in YEM broth at pH 4.5 were also resistant to 400 µM Al on the YEM plates. Acetylene reduction assay of the root nodules revealed that 3 of the acid- and Al-tolerant isolates from Indonesian soils showed a significantly high nitrogen fixation activity.     

Effect of boiled barley-rice-feeding in hypercholesterolemic and normolipemic subjects

Barley contains approximately 10% dietary fiber and is easily cooked with rice, the dominant cereal in Japan, to increase the intake of dietary fiber. This research involved three experiments to examine the influence of barley on blood lipids in human subjects. All subjects received a boiled barley-rice (50/50 w/w mix) supplement two times per day in place of rice for 2 or 4 weeks. In the normolipemic subjects, serum lipids were unaffected by the ingestion of barley for 4 weeks. In twenty hypercholesterolemic men aged 41 ± 5 years, the ingestion of barley was associated with a significant fall in serum total cholesterol, LDL-cholesterol, phospholipids and LDL and VLDL-lipoproteins. In seven mildly hypercholesterolemic women aged 56±7 years, a significant improvement of serum lipid profiles was observed. The present study suggests the possibility that the ingestion of barley-rice could lower serum lipids in hypercholesterolemic subjects.     

Metyltetraprole activity against plant pathogens with relatively rare cytochrome b haplotypes for azoxystrobin resistance

Journal of General Plant Pathology - Metyltetraprole is a novel quinone outside inhibitor (QoI) fungicide designed to avoid cross-resistance in cytochrome b G143A-harboring QoI-resistant...     

Field trap test for bioassay of synthetic (1<Emphasis Type="Italic">S</Emphasis>,4<Emphasis Type="Italic">R</Emphasis>)-4-isopropyl-1-methyl-2-cyclohexen-1-ol as an aggregation pheromone of <Emphasis Type="Italic">Platypus quercivorus</Emphasis> (Coleoptera: Platipodidae)

An ambrosia beetle, Platypus quercivorus, is a vector of Japanese oak wilt, which causes massive mortality of oak trees in Japan. Previous studies have identified (1S,4R)-4-isopropyl-1-methyl-2-cyclohexen-1-ol ((−)-IMCH) as the major component of the aggregation pheromone of P. quercivorus. We tested the ability of synthetic (−)-IMCH to attract P. quercivorus adults. The synthetic compound attracted 14.4 times as many P. quercivorus, of both sexes, as control traps. Control and (−)-IMCH-baited traps both captured 3.32 times as many males as females, probably because of the nature of Lindgren funnel traps and of male-biased emergence sex ratio early in the season of adult flights. (−)-IMCH was proved to be a major component of the aggregation pheromone of P. quercivorus.     

A selective barrier in the midgut epithelial cell membrane of the nonvector whitefly <Emphasis Type="Italic">Trialeurodes vaporariorum</Emphasis> to <Emphasis Type="Italic">Tomato yellow leaf curl virus</Emphasis> uptake

We studied the presence of a potential transmission barrier that blocks Tomato yellow leaf curl virus in the nonvector greenhouse whitefly, Trialeurodes vaporariorum. Because T. vaporariorum can ingest and retain the virus after acquisition feeding on an infected plant, comparable to the vector whitefly Bemisia tabaci, circumstance evidence suggested that a transmission barrier presents at location(s) where the virus moves from the digestive tract lumen to the hemolymph. To provide direct evidence for the site of a transmission barrier in the nonvector insect, we compared the accumulation levels and localization of the virus between the two species of whiteflies. Quantitative real-time and conventional PCR analysis showed that accumulation of the virus during acquisition feeding and retention after a short acquisition period were indistinguishable between the two species, but the circulation of the virus within the whiteflies differed significantly between the species. In an immunofluorescence analysis using an antibody specific to the coat protein of the virus, the virus was restricted to the luminal surface of the midgut epithelial cells and did not enter their cytoplasm or that of the salivary glands in T. vaporariorum. In contrast, the virus was localized within the cytoplasm of the midgut epithelial cells and in the paired salivary glands of B. tabaci adults. This direct evidence shows that a selective transmission barrier at the luminal membrane surface of midgut epithelial cells in the nonvector whitefly blocks entrance of the virus into the midgut epithelial cells, resulting in incompetence as a vector of the virus.     

Identification of a bacterium isolated from galls on carrot and weeds

In 2004, bacterial galls were found on the roots of carrots in Shizuoka Prefecture, Japan. Galls were about 0.1–2 cm in diameter, light brown in color and had rough surfaces. In 2005, similar galls were found on the roots of three weeds: henbit (Lamium amplexicaule L.), Persian speedwell (Veronica persica Poir.) and leaf mustard (Brassica juncea L.). A bacterium that forms white, rough colonies was isolated from the carrot and weeds galls. The bacterial isolates had properties identical with Rhizobacter dauci Goto and Kuwata. Phylogenetic analysis based on 16S rDNA sequences showed that the carrot isolate had the highest homology (similarity of 100%) with that of the type strain of R. dauci. Rep-PCR genomic fingerprinting using BOX A1R primer showed that the carrot and weeds isolates were nearly identical. Pathogenicity of the isolates was confirmed by inoculating the roots of carrots and the weeds. After 2–5 weeks, they formed galls on the roots of the original host species and on other plant species tested. The galls were indistinguishable from those formed naturally, and the inoculated bacterium was reisolated. Thus, the causal bacterium of carrot and weeds gall was identified as R. dauci, and the bacterium was found to have a wider host range than previously known. These weed hosts may serve as inoculum sources for carrot bacterial gall disease.