Effects of light quality on conidiophore formation of the melon powdery mildew pathogen <Emphasis Type="Italic">Podosphaera xanthii</Emphasis>     

Tomoko Suzuki  Shougo Nishimura  Kazuhiro Yagi  Ryousuke Nakamura  Yoshihiro Takikawa  Yoshinori Matsuda  Koji Kakutani  Teruo Nonomura 《Phytoparasitica》2018,46(1):31-43

The lengths of conidiophores in fungal colonies of the melon powdery mildew pathogen Podosphaera xanthii Pollacci KMP-6 N cultured under greenhouse (natural) conditions differed markedly from those cultured in a growth chamber. We hypothesized that light wavelength was responsible for the differences in conidiophore length. In this study, we examined the effects of light-emitting diode (LED) irradiation (purple, blue, green, orange, and red light) and white light on colony development and conidiophore formation in KMP-6 N using a stereomicroscope and a high-fidelity digital microscope. Colonies on leaves were flat under greenhouse conditions and under red LED light irradiation but were stacked under growth chamber conditions and under purple, blue, green, and orange LED light irradiation. In addition, KMP-6 N formed catenated conidia comprising six conidia per conidiophore under greenhouse conditions and red light but more than seven conidia per conidiophore under growth chamber conditions and purple, blue, green, and orange light. Furthermore, almost none of the conidia on top of the conidiophores grown under blue light were fully constricted. Therefore, these fungi could not scatter their conidia and spread infection. This is the first report of the effects of LED lights on conidiophore formation in the melon powdery mildew fungus P. xanthii. The results provide insight into the mechanisms underlying the responses of conidiophores to light of specific wavelengths and conidial scatter from conidiophores of melon powdery mildew fungi.  相似文献   

Ecology and conservation of two endangered subspecies of the leopard cat (Prionailurus bengalensis) on Japanese islands     

Masako Izawa  Teruo Doi  Ayumi Teranishi 《Biological conservation》2009,142(9):1884-1890

The conservation of rare species on islands is a special challenge, especially when the islands are faced with increasing human impact. Two endangered wild felids in Japan provide a contrast that is useful for examining conservation strategies. The Iriomote cat (Prionailurus bengalensis iriomotensis) is endemic to Iriomotejima Island in Okinawa, and the Tsushima leopard cat (Prionailurus bengalensis euptilurus) occurs in the Tsushima islands in Japan, although a related subspecies found in the Korean Peninsula. Population size was approximately 100 individuals for each subspecies. While the population of Iriomote cat appears relatively stable, the population and abundance of the Tsushima leopard cat has decreased in recent decades. Because of their small population sizes and restricted habitats both are listed as endangered species/subspecies in Japan’s Red List, and the Iriomote cat is listed as an endangered subspecies in the IUCN Red List. Although both are similar-sized felids living on small islands, their ecological characteristics such as food habit, habitat selection, and density differ. These differences seem to be caused by the climate, the biological environment (the species composition of fauna in each island, and the presence of competitors), and the artificial background. The threats facing these two felids are also similar. Habitat destruction, traffic accidents, and negative influences by introduced species are the principal threats to be addressed for their conservation. At the same time, there are differences in the degree of impact by each threat, in each species’ conservation programs in practice, and in the stages of progress and operation of programs. These differences are partly because they have different ecological features and partly because the social background of each island, such as human population, main industry, and historical relationship between human and wildlife, are quite different. We will compare the ecology and state of these two wild felids and discuss the different conservational situations in relation to felid ecology and human society.  相似文献   

The membrane‐type estrogen receptor G‐protein‐coupled estrogen receptor suppresses lipopolysaccharide‐induced interleukin 6 via inhibition of nuclear factor‐kappa B pathway in murine macrophage cells          下载免费PDF全文

Mariko Okamoto  Takuto Suzuki  Yoichi Mizukami  Teruo Ikeda 《Animal Science Journal》2017,88(11):1870-1879

The female sex hormone estrogen exerts anti‐inflammatory effects. The G‐protein‐coupled estrogen receptor (GPER) has been recently identified as a novel membrane‐type estrogen receptor that can mediate non‐genomic estrogenic effects on many cell types. We previously demonstrated that GPER inhibits tumor necrosis factor alpha‐induced expression of interleukin 6 (IL‐6) through repression of nuclear factor‐kappa B (NF‐κB) promoter activity using human breast cancer cells. Although several reports have indicated that GPER suppresses Toll‐like receptor‐induced inflammatory cytokine expression in macrophages, the molecular mechanisms of the inhibition of cytokine production via GPER remain poorly understood. In the present study, we examined GPER‐mediated inhibition of IL‐6 expression induced by lipopolysaccharide (LPS) stimulation in a mouse macrophage cell line. We found that the GPER agonist G‐1 inhibited LPS‐induced IL‐6 expression in macrophage cells, and this inhibition was due to the repression of NF‐κB promoter activity by GPER. G‐1 treatment also decreased the phosphorylation of inhibitor of κB kinases. Among the mitogen‐activated protein kinases, the phosphorylation of c‐jun N‐terminal kinase (JNK) was increased by G‐1. These findings delineate the novel mechanism of the inhibition of LPS‐induced IL‐6 through GPER‐activated JNK‐mediated negative regulation of the NF‐κB pathway in murine macrophage cells, which links anti‐inflammatory effects to estrogen.  相似文献   

Behavioural analysis of a nonionic detergent in the kraft pulp washing process using cryo-time-of-flight secondary ion mass spectrometry and cryo-scanning electron microscopy     

Katsuhiro Tokugawa  Dan Aoki  Ryutaro Asai  Yasuyuki Matsushita  Masao Ishiguro  Yasufumi Noda  Kazuhiko Fukushima 《Journal of Wood Science》2017,63(3):281-287

In order to understand the kraft pulp decolouring mechanism on using a nonionic detergent, the pulp washing process and the resulting pulp handsheets were investigated by examining the brightness, kappa number, thioacidolysis product yield, and dewatering efficiency in the pressing sheet making process. The pulp decolouring could be attributed to a decrease in the lignin content and an improvement in the dewatering efficiency. Furthermore, the detergent distribution in the aqueous pulp suspension obtained during the pulp washing process was visualised using cryo-time-of-flight secondary ion mass spectrometry/scanning electron microscopy (cryo-TOF-SIMS/SEM). The detergent was clearly observed at the transverse surface of the pulp fibre cell wall and was also detected in the lumen of the fibres, suggesting the permeation of the detergent into the pulp fibre cell wall. Based on these results, the pulp decolouring mechanism can be proposed as follows: the detergent permeates into the pulp fibre cell wall and promotes the solution-exchange between the inside and the outside parts of the fibre cell wall, finally washing away the chromophoric substances such as lignin and its degradation products owing to the enhanced dewatering efficiency.  相似文献   

Cutting rot of chrysanthemum (<Emphasis Type="Italic">Chrysanthemum morifolium</Emphasis>) caused by <Emphasis Type="Italic">Plectosporium tabacinum</Emphasis>     

Mamoru Satou  Yoshiaki Chikuo  Yosuke Matsushita  Katsuhiko Sumitomo 《Journal of General Plant Pathology》2010,76(3):225-228

Cutting rot of chrysanthemum was found on cuttings of cv. Jimba No.2 in 2008. The cuttings were imported, then transplanted in Aichi Prefecture. Root development was not initiated in about 30% of the cuttings. The cut stem ends developed black discolouration and decay. When healthy cuttings were the fungus isolated from diseased cuttings, these cuttings developed the same disease symptoms. The characteristics and morphology of the fungal culture were identical to those of Plectosporium tabacinum. We propose that the new disease be named cutting rot of chrysanthemum.  相似文献   

Interference with cell-to-cell movement of <Emphasis Type="Italic">Tomato mosaic virus</Emphasis> by transient overexpression of <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> KELP homologs from different plant species     

Nobumitsu Sasaki  Tatsuro Odawara  Masakazu Deguchi  Yasuhiko Matsushita  Hiroshi Nyunoya 《Journal of General Plant Pathology》2010,76(1):69-73

The KELP protein of Arabidopsis thaliana (AtKELP), which binds to the Tomato mosaic virus (ToMV) movement protein in vitro, can interfere with cell-to-cell movement of the virus under transient overexpression conditions. In this study, we constructed expression plasmids encoding a fluorescent protein fused to AtKELP or to its homolog from Brassica, Nicotiana, Solanum, or Oryza species. When expressed transiently, all the AtKELP homologs inhibited the cell-to-cell movement of ToMV with different efficiencies. The results of domain swapping between two selected AtKELP homologs suggest the importance of combination between the N- and C-terminal half regions for high inhibitory function.  相似文献   

Pathogenicity of <Emphasis Type="Italic">Mycochaetophora gentianae</Emphasis>, causal fungus of gentian brown leaf spot,as affected by host species,inoculum density,temperature, leaf wetness duration,and leaf position     

Syuuichi Nekoduka  Kazuaki Tanaka  Teruo Sano 《Journal of General Plant Pathology》2010,76(6):370-376

When the influence of host species, inoculum density, temperature, leaf wetness duration, and leaf position on the incidence of gentian brown leaf spot caused by Mycochaetophora gentianae, was examined, the fungus severely infected all seven Gentiana triflora cultivars, but failed to infect two cultivars of G. scabra and an interspecific hybrid cultivar. Inoculum density correlated closely with disease incidence, and a minimum of 10² conidia/mL was enough to cause infection. In an analysis of variance, temperature and leaf wetness duration had a significant effect upon disease incidence, which increased with higher temperature (15–25°C) and longer duration of leaf wetness (36–72 h). No disease developed at temperatures lower than 10°C or when leaf wetness lasted <24 h. At 48-h leaf wetness, disease incidence was 0, 28, 77, and 85% at 10, 15, 20, and 25°C, respectively. Middle and lower leaves on the plant were more susceptible than upper leaves. In microscopic observations of inoculated leaves, >50% of conidia germinated at temperatures >15°C after 24-h leaf wetness. More appressoria formed at higher temperatures (15–25°C) with extended duration of leaf wetness (24–72 h). At 48-h leaf wetness, appressorium formation was 0, 8, 26, and 73% at 10, 15, 20, and 25°C, respectively. These results suggest that temperature and leaf wetness duration were important factors for infection of gentian leaves.  相似文献   

Overwintering of <Emphasis Type="Italic">Taphrina wiesneri</Emphasis> within cherry shoots monitored with species-specific PCR     

Masabumi Komatsu  Machiko Taniguchi  Norihisa Matsushita  Yukiko Takahashi  Taizo Hogetsu 《Journal of General Plant Pathology》2010,76(6):363-369

Taphrina wiesneri, the pathogen of witches’ broom of cherry, is highly pathogenic to Cerasus × yedoensis, the most widely planted ornamental cherry species in Japan. For adequate control of this disease, it is necessary to understand the life history of T. wiesneri. However, sites inhabited by T. wiesneri within infected trees are little understood, except during flowering and leafing periods in spring. Therefore, we attempted to detect the location of T. wiesneri in shoots of witches’ broom before flowering and leafing in spring using PCR with a T. wiesneri-specific primer pair that was designed from 69 sequences in rDNA-internal transcribed spacer region of 32 Taphrina species. DNA extracted from symptomatic and asymptomatic C. × yedoensis sampled before leafing was amplified by PCR. T. wiesneri was detected in every bud and 5-mm stem segment of symptomatic shoots, except for one stem segment, and locally inside buds and the inner bark of stem segments. These results indicate that T. wiesneri overwinters inside symptomatic shoots. Fungal hyphae were observed with an epifluorescence microscope in intercellular spaces of young leaves in symptomatic buds but not in asymptomatic ones in thin sections stained with fluorescein-isothiocyanate-conjugated concanavalin A. This observation supports the results of PCR detection.  相似文献   

Naphthalene derivatives from Diospyros kaki     

Yasuyuki Matsushita  In-Cheol Jang  Takanori Imai  Kazuhiko Fukushima  Seung-Cheol Lee 《Journal of Wood Science》2010,56(5):418-421

A detailed chemical investigation of the extractives of the blackened heartwood of Diospyros kaki was carried out to understand their chemical characteristics and to obtain chemotaxonomic information. Three novel naphthalene derivatives were isolated, i.e., 4-hydroxy-5,6-dimethoxy-2-naphthaldehyde (1), 5,6,8-trimethoxy-3-methyl-1-naphthol (2), and 4,8-dihydroxy-5-methoxy-2-naphthaldehyde (3), in addition to two previously reported 2-naphthaldehydes: 4-hydroxy-5,8-dimethoxy-2-naphthaldehyde (4) and 4-hydroxy-5-methoxy-2-naphthaldehyde (5) Their structures were identified by 1D and 2D nuclear magnetic resonance spectroscopy, as well as by high-resolution mass spectrometry.  相似文献   

Competitive Removal of Heavy Metals from Aqueous Solutions by Montmorillonitic and Calcareous Clays     

Ali Sdiri  Teruo Higashi  Rochdi Chaabouni  Fakher Jamoussi 《Water, air, and soil pollution》2012,223(3):1191-1204

A batch sorption method was used to study the removal of few toxic metals onto the Late Cretaceous clays of Aleg formation (Coniacian–Lower Campanian system), Tunisia, in single, binary and multi-component systems. The collected clay samples were used as adsorbents for the removal of Pb(II), Cd(II), Cu(II) and Zn(II) from aqueous solutions. Results show that the natural clay samples were mainly composed of silica, alumina, iron and magnesium oxides. N₂-adsorption measurements indicated mesoporous materials with modest specific surface area of <71 m²/g. Carbonate minerals were the most influencing parameters for heavy metal removal by natural clays in both single and multi-element systems. The affinity sequence was Pb(II)>Cu(II)>Zn(II)>Cd(II) due to the variable physical properties of the studied metals. The maximum adsorption capacity reached 131.58 mg/g in single systems, but decreased to <50.10 mg/g in mixed systems. In single, binary and muti-element systems, the studied clay samples removed substantial amounts of heavy metals, showing better effectiveness than the relevant previous studies. These results suggest that the studied clay samples of the Late Cretaceous clays from Tunisia can be effectively used as natural adsorbents for the removal of toxic heavy metals in aqueous systems.  相似文献