Indole-3-acetic acid biosynthesis in <Emphasis Type="Italic">Aciculosporium take</Emphasis>, a causal agent of witches' broom of bamboo

 Aciculosporium take (Ascomycota; Clavicipitaceae) is a causal agent of witches' broom of bamboo plants. The symptoms of this disease are believed to be induced by plant hormones, particularly auxins. Indole-3-acetic acid (IAA) was identified in cultures of this fungus in an l-tryptophan-supplemented liquid medium. IAA production was confirmed on 30 isolates of A. take from various hosts and locations at levels up to 1 mg/l. The biosynthetic pathway of IAA in A. take culture was examined by analyzing intermediate products and by feeding experiments. The results showed that the indole-3-pyruvic acid pathway (l-tryptophan → indole-3-pyruvic acid → indole acetaldehyde → IAA) was the dominant pathway in A. take. Received: June 3, 2002 / Accepted: July 25, 2002     

Competitive enzyme-linked immunosorbent assay for the detection of the antibodies specific to akabane virus.

A competitive enzyme-linked immunosorbent assay (C-ELISA) using neutralizing monoclonal antibodies (MAbs) against Akabane virus (AKAV) was developed to detect antibodies to AKAV in cattle sera. The performance of the test using 7 different competitor MAbs was evaluated in sequential serum samples and sera from cattle infected with various bovine arboviruses. The dynamics of the antibody response expressed by percentage of inhibition (PI) in C-ELISA coincided with those of neutralizing antibody titers in sequential serum samples from 2 cattle experimentally infected with AKAV. The value of PI in C-ELISA for convalescent sera from cattle infected with arboviruses correlated with the neutralizing antibody titer to AKAV but was unaffected by the antibodies to other arboviruses. In the validation experiment of C-ELISA using 286 bovine sera previously examined for the AKAV antibody by serum neutralization (SN) test, the relative specificity of C-ELISA was more than 98%, whereas the relative sensitivities of individual MAbs ranged from 49% to 82.2%. Overall agreement between C-ELISA and the SN test varied from 72% to 90% depending on the MAb. These results suggest that the C-ELISA is acceptable as a rapid and specific method for detecting antibodies to AKAV and is a potential alternative to the SN test.     

Suppurative meningoencephalitis and perineuritis caused by Streptococcus gallolyticus in a Japanese Black calf

A 179-day-old calf, which was weak and stunted, showed neurological signs and was euthanized. Postmortem examination revealed extensive and severe cloudy area in the meninges, and pleural pneumonia. Gram-positive cocci were isolated from systemic organs. Biochemical and 16S rRNA gene sequence analyses identified the isolate as Streptococcus gallolyticus, and its subspecies was suggested to be gallolyticus (SGG). The isolate was classified as a novel sequence type (ST115) by the multilocus sequence typing scheme for SGG and showed susceptibility to penicillin, ampicillin, amoxicillin, florfenicol, sulfamethoxazole-trimethoprim, and chloramphenicol. Histopathologically, suppurative meningoencephalitis and perineuritis were detected. As SGG has been isolated solely from a cow with mastitis in Japan, this is the first SGG infection in a calf with suppurative meningoencephalitis and perineuritis in this country.     

Analysis of mesh breaking loads in cotton gill nets: Possible solution to ghost fishing

ABSTRACT:   A small number of fishers in Chiba Prefecture of eastern Japan use cotton gill nets to catch Japanese spiny lobster Panulirus japonicus. To examine the advantages of cotton gill nets, we analyzed changes in mesh breaking load of a new cotton gill net used in a fishing operation. A new cotton gill net was also soaked in a seawater tank to simulate ghost fishing conditions. The average mesh breaking load of new cotton mesh was 50.3 N. This value decreased to 19.0 N after 38 days (∼912 h), and after 82 days (∼1968 h) the mesh could be easily torn (breaking load 0.07 N). Under fishing conditions, the cumulative soak time was only 744.4 h over 19 months. The average breaking load at the end of this period was 43.1 N, a strength 86% that of the presoaked mesh. The mesh breaking load of a cotton gill net continuously soaked for 744.4 h was 26.1 N, as estimated from tank experiment data. Thus, a cotton gill net maintains reasonable strength under typical use conditions, but will degrade if lost at sea.     

Potassium behavior and clay mineral composition in the soil with low effectiveness of potassium application

ABSTRACT

Increasing exchangeable potassium (ExK) content in soil to an appropriate level is important to mitigate the transfer of radioactive cesium to crops. We focused on a buckwheat (Fagopyrum esculentum Moench) field with a low ExK content, despite the application of K, in Fukushima Prefecture, Japan (Field A), following the Tokyo Electric Power Company Fukushima Dai-ichi (No. 1) Nuclear Power Plant accident in March 2011. We examined the relationship between K concentration and clay mineral composition in the soil of Field A and compared the findings with another field in Fukushima Prefecture (Field B) to clarify whether K applied to the soil was leached or remaining fixed. Pot experiments showed that K concentration in water seepage from pots following irrigation was significantly lower in pots from Field A than in those from Field B. Soil ExK content after soybean cultivation was lower in soils of Field A than those of Field B. These results indicate that K applied to Field A was fixed in the soil. Analysis of clay mineral composition confirmed the distinctive vermiculitic nature of Field A soils. This clay mineralogy would be associated with the higher K fixation ability of Field A than Field B soils. This study demonstrated that K fixation in vermiculite was a factor preventing the increase in ExK content from K application to Field A.     

A plant vacuolar protease, VPE, mediates virus-induced hypersensitive cell death

Programmed cell death (PCD) in animals depends on caspase protease activity. Plants also exhibit PCD, for example as a response to pathogens, although a plant caspase remains elusive. Here we show that vacuolar processing enzyme (VPE) is a protease essential for a virus-induced hypersensitive response that involves PCD. VPE deficiency prevented virus-induced hypersensitive cell death in tobacco plants. VPE is structurally unrelated to caspases, although VPE has a caspase-1 activity. Thus, plants have evolved a regulated cellular suicide strategy that, unlike PCD of animals, is mediated by VPE and the cellular vacuole.     

Effects of genes increasing the number of spikelets per panicle,TAW1 and APO1, on yield and yield-related traits in rice

The genes TAWAWA1 (TAW1) and ABERRANT PANICLE ORGANIZATION1 (APO1) increase the number of spikelets per panicle (SN). In the present study, we examined the effects of these genes on morphological traits, yield, and yield-related traits including yield components using the near-isogenic lines (NILs) in the genetic background of a japonica rice variety, Koshihikari – NIL-taw1, NIL-apo1-D3, and NIL-apo1-D4 – in a field experiment. The SN and total number of spikelets per area of the three NILs were larger than those of Koshihikari. However, the yield of the three NILs did not exceed that of Koshihikari due to their low filling ability. Interestingly, our field experiments indicated that TAW1 did not affect the diameter of internodes and the PN, whereas APO1 decreased the PN and increased the diameter of internodes. These results suggest that TAW1 and APO1 differently affect yield-related traits.     

Production of patchouli mild mosaic virus resistant patchouli plants by genetic engineering of coat protein precursor gene

Patchouli (Pogostemon cablin (Blanco) Benth), an aromatic crop which yields an essential oil, is widely cultivated in South-east Asia. Patchouli mild mosaic virus (PaMMV) infects patchouli plants and causes decrease in leaf biomass and essential oil yield. Transgenic patchouli plants with PaMMV coat protein precursor (CP-P) gene have been produced by Agrobacterium-mediated transformation. PaMMV CP-P gene integration into the patchouli genome was confirmed by the PCR method and by Southern blot analysis. The transformants were estimated to contain one to three copy genes using Southern blot analysis. The transformant with three copy genes was tested for the resistance to PaMMV by artificially inoculating plants grown in an environmentally controlled cabinet, and this transformant was found to be highly resistant to PaMMV. The transgenic patchouli plant with PaMMV CP-P gene should provide valuable material for protecting against PaMMV.