棉花枯萎病菌的致病性及其碳素营养的试验研究

南通棉花枯萎病菌对22个棉花品种致病性的田間和盆栽試驗说明:中棉品种如辽阳一号、鶯湖棉、长丰黑籽、常紫一号、南通白花鸡脚桠鈴果、云南布沼土棉等抗病性比較強,以中棉为母本的中印杂交棉的抗病性也較強;陆地棉和海島棉一般感病程度都較高,但四川选育的陆地棉品种52—128則具有一定的抗病性。将枯萎病菌接种到甘藷等27种作物上,均未感病。五个地区的棉花枯萎病菌致病性的盆栽試驗说明:四川、陝西、辽宁的病原菌致病力較強,江苏的其次,安徽的最弱。以葡萄糖、果糖、半乳糖、甘露糖、乳糖、蔗糖、菊糖、溶解淀粉、阿拉伯糖醇等九种糖和糖醇为碳素营养料时,除四川的病原菌在以半乳糖为碳素营养料时生长中等外,其他都生长旺盛。不同地区病原菌的色素形成、小型孢子、大型孢子和厚膜孢子的产生,随碳素营养料的不同而有所差異。     

Affinity isolation and mass spectral analysis of 1,10-phenanthroline (OP)-stimulated UV-damaged-DNA binding proteins expressed in zebrafish (Danio rerio) embryos

Our earlier studies indicated the high expression of a UV-damaged-DNA binding activity in zebrafish (Danio rerio) embryos at 12?h postfertilization (hpf). Two 30- to 35-kDa polypeptides homologous to the N-terminal lipovitellin 1 (Lv1) domain of the 150-kDa zebrafish vitellogenin 1 (zfVg1) were identified as the damage recognition factors in zebrafish extracts, and the metal-chelating agent 1,10-phenanthroline (OP) was found to inhibit the embryonic UV-damaged-DNA binding activity. This study further explored the DNA damage-sensing components in 12 hpf zebrafish extracts. UV-damaged-DNA binding proteins were enriched from zebrafish extracts by isoelectrofocusing. Both OP-sensitive and OP-stimulated, UV-damaged-DNA binding activities were detected in fractionated zebrafish extracts. Two-dimensional gel electrophoresis of proteins captured by an immobilized oligonucleotide carrying a UV-induced (6-4)photoproduct (6-4PP) revealed a 25-kDa polypeptide as the major 6-4PP-binding factor in an OP-stimulated fraction. Three 25-kDa factors that bound weakly to 6-4PPs were also isolated. The four polypeptides having pIs between 7.0 and 7.3 were unreactive to an anti-zfVg1 antibody targeting the Lv1 domain. Mass spectral analysis showed the appearance of amino acid sequences LPIIVTTYAK and IPEITMSK in all 25-kDa polypeptides and sequences exactly matching those contained in the four factors exist only in the C-terminal Lv2 domain of zfVg1, reflecting the origination of these factors from enzymatic cleavage of the Lv2 domain at slightly different positions. The OP-stimulated fraction produced a much stronger UV-dependent DNA incision activity in the presence than in the absence of OP, suggesting the association of these factors with DNA damage repair under metal-deficient conditions.     

Profiles of thyrotropin,thyroid hormones,follicular cells and type I deiodinase gene expression during ontogenetic development of tilapia larvae and juveniles

The aims of the present study are to determine whether triiodothyronine (T3) and/or thyroxine (T4) in tilapia larvae is gifted through the mother, and to investigate the change profiles of thyrotropin (TSH), thyroid follicular cells and type I deiodinase (D1) gene expression following larval development. T3 and T4 contents were measured using radioimmunoassay, thyrotropin was observed using immunocytochemistry, and the D1 gene was cloned and measured using real-time PCR. Results indicated that the β-TSH-immunoreactive cells (thyrotropin ICC) signals were detected at 9 dph (i.e., 9 days of post-hatching). Thyroid follicular cells were observed first at 3 dph, while the T3 contents of the whole body gradually decreased before 11 dph. T4 contents were detected until 13 dph, with higher secretion during 19–21 dph. In addition, the T3 synthesis was not inhibited by thiourea (TU) before 13 dph, but the TU response in the larvae appeared after 13 dph. Type I deiodinase (D1: GenBank accession number KC591724) was found to contain 2444 bases and encoded 248 amino acids. The D1 mRNA expression began to increase at 13 dph, with a higher expression during 15–19 dph. These results suggested that the T3 contents were maternally derived before 13 dph. Both thyroid hormonal changes and some parameters related to thyroid hormone synthesis in ontogenetic tilapia are discussed.     

Effects of Chloroformic Extracts from Washed and Unwashed Papaya Seeds (Carica papaya) on the Sperm Concentration of Dogs

Papaya seeds (Carica papaya Linn) have been found to have a significant effect on sperm characteristics in some mammals, including humans, but no studies have investigated the effects on dogs. In the present study, a significant decrease in sperm concentration was observed in a group of dogs treated with extracts from washed papaya seeds, but no decrease was observed in the group of dogs treated with non‐washed seeds. An important effect of extract components from washed seeds such as fatty acids is probably involved in the reduction of sperm production because of Sertoli cell damage, as has been suggested for langur monkeys. Dilution of the active components in the non‐washed papaya seeds or interference with some of the components may reduce the expected effect on spermatogenesis. This first report on the effects of a chloroformic extract of papaya seeds in dogs suggests that an increased dose is necessary to achieve azoospermia.     

Avian assemblages in eucalypt forests,plantations and pastures in northern NSW,Australia

Eucalypt plantations are expanding rapidly in Australia, and their value for native fauna requires investigation. The relative conservation value of young eucalypt plantations was investigated through assessment of avifauna richness, abundance and composition using transect surveys incorporating point counts in five broad habitat types—dryland forests, riparian forests, dryland plantations, riparian plantations, and riparian pastures (strips of riparian vegetation surrounded by pastures). A total of 73 species were recorded during formal surveys. Species richness and abundance were comparable among all habitat types except dryland plantations, which supported fewer species and in lower numbers. The avifauna assemblage differed according to broad habitat types. Forest habitats (dryland and riparian) harboured more forest- and woodland-dependent species, and a greater abundance of nectarivores and insectivores. Riparian plantations supported a similar number of forest- and woodland-dependent species to forest habitats, but also retained some open-country species. Riparian pastures had the highest cumulative species richness, reflecting a diverse mix of forest- and woodland-dependent birds and open-country species. It was the preferred habitat type for granivores and vertebrate eaters. Dryland plantations were dominated by common species and omnivores, and supported fewer forest- and woodland-dependent birds, insectivores and frugivores compared with other habitat types. The presence of riparian strips increased avifauna diversity and abundance in plantations and pastures to a greater extent than predicted by the proportional area of riparian habitat. The importance of riparian habitats needs to be recognised and incorporated into management policies if biodiversity conservation is to be an objective of plantation establishment.     

Heat tolerance in English ivy as measured by an electrolyte leakage technique

Summary

Identification of heat-tolerant English ivy (Hedera helix L.) genotypes for commercial production in hot areas is desirable. The extent to which electrolyte leakage from English ivy leaf discs, measured using a test for cell membrane thermostability (CMT), could be related to the reduction to shoot dry weight induced by heat in the greenhousegrown plants was determined. A curved relationship existed between the relative injury (RI) value occurring in leaf tissue discs of English ivy cultivars and treatment temperature. A single temperature treatment at 50°C resulted in injury values near the midpoint of the response curve and showed the greatest sensitivity in detecting genotypic differences in heat tolerance. The cultivars with a high RI value are those with the lesser CMT and more reduction in shoot dry weights by high day/night temperature at 35/30°C.     

4-Shogaol, an active constituent of dietary ginger, inhibits metastasis of MDA-MB-231 human breast adenocarcinoma cells by decreasing the repression of NF-κB/Snail on RKIP

4-Shogaol is one of the phytoconstituents isolated from dried red ginger, which is commercially available to consumers. Some active constituents from ginger have been found to have anti-inflammatory and antioxidant effects, but studies on 4-shogaol have been relatively rare. This is the first report describing the antimetastasis activities of 4-shogaol and the possible mechanisms. This study determined that 4-shogaol inhibits the migration and invasion of MDA-MB-231 and causes mesenchymal-epithelial transition (MET). In addition, 4-shogaol suppresses the activation of NF-κB and cell migration and invasion induced by TNF-α. Furthermore, 4-shogaol has been shown to inhibit the phosphorylation of IκB and the translocation of NF-κB/Snail in MDA-MB-231. This study shows that RKIP, an inhibitory molecule of IKK, is up-regulated after 4-shogaol treatment and prolongs the inhibitory effects of 4-shogaol. Inhibition of RKIP by shRNA transfection significantly decreases the inhibitory effect of 4-shogaol on the NF-κB/Snail pathway, together with cell migration and invasion, whereas overexpression of Snail suppresses 4-shogaol-mediated metastasis inhibition and E-cadherin upregulation. Finally, the animal model revealed that 4-shogaol effectively inhibits metastasis of MDA-MB-231 in mice. This study demonstrates that 4-shogaol may be a novel anticancer agent for the the treatment of metastasis in breast cancer.     

Isoobtusilactone A sensitizes human hepatoma Hep G2 cells to TRAIL-induced apoptosis via ROS and CHOP-mediated up-regulation of DR5

Hepatoma cells are relatively resistant to TRAIL. We have previously shown that isoobtusilactone A (IOA), a potent anticancer agent isolated from Cinnamomum kotoense, induced mitochondria-mediated apoptosis in hepatoma cells. Here, we report that IOA could potentiate TRAIL-induced apoptosis in Hep G2 cells. The combined treatment with IOA and TRAIL significantly induced caspase-dependent apoptosis. This correlated with the up-regulation of C/EBP homologous protein (CHOP) and death receptor 5 (DR5) protein levels. Gene silencing of the DR5 by small interfering RNA abrogated the apoptosis induced by the combined regimen of IOA and TRAIL, suggesting that the sensitization to TRAIL was mediated through DR5. By analyzing the DR5 promoter, we found that IOA induced a CHOP-dependent DR5 transactivation. DR5 expression after IOA treatment was accompanied by provoking intracellular reactive oxygen species (ROS) generation. Pretreatment with N-acetyl-L-cysteine (NAC) attenuated IOA-induced CHOP and DR5 expression and inhibited TRAIL-induced apoptosis. Taken together, our data suggested that ROS-dependent and CHOP-regulated DR5 expression played a pivotal role in the synergistic enhancement of TRAIL-induced apoptosis instigated by IOA in Hep G2 cells.     

nardosinane-type sesquiterpenoids from the formosan soft coral Paralemnalia thyrsoides

Five new nardosinane-type sesquiterpenoids, paralemnolins Q-U (1-5), along with three known compounds (6-8), were isolated from the Formosan soft coral Paralemnalia thyrsoides. The structures of new metabolites were elucidated on the basis of extensive spectroscopic methods, and the absolute configuration of 1 was determined by the application of Mosher's method on 1. Among these metabolites, 1 and 3 are rarely found nardosinane-type sesquiterpenoids, possessing novel polycyclic structures. Compounds 1, 3, 6 and 7 were found to possess neuroprotective activity.