Specific and non-specific adsorption of inorganic ions I. Evaluation of specific adsorbability by means of minimum concentration for specific adsorption

The Minimum Concentration for Specific Adsorption (MCSA) was defined as a reversal of the charge concentration of the ion at the infinite dilution of sol (adsorbent), or practically at such concentration of sol that equilibrium of the ion Is but negligibly affected by adsorption of the ion.

The MCSAs of 15 species of cations were measured with respect to SiO₂ at pH 4,6,5, and 10; the MCSAs of 10 species of anions were measured with respect to Fe(OH)₃ at pH 4, and 6.5; and the MCSAs of 10 species of anions were measured with respect to Al-coated-SiO₂ at pH 6.5. Relative specificities of the inorganic ions based on the MCSAs at pH 6.5 were as follows:

The MCSAs of cations with respect to SiO₂ and of anions to Fe(OH)₃ and Al-coated-SiO₂ at pH 6.5 had close relationships to ionic potentials and general solubility of the elements in water. Based on these results, the authors concluded that the MCSA could be used u an index of specificity (i.e. covalent bond-forming tendency) of an Jon at adsorption reactions.

The values corresponding to the apparent stability constants of surface complexes formed by adsorption reaction with SiO₂ and cations at pH 4 were calculated from the values of the MCSAs.     

The plasma membrane intactness of root-tip cells is a primary factor for Al-tolerance in cultivars of five species

We investigated the role of the cell wall and plasma membrane (PM) of root-tip cells in Al tolerance in Al-tolerant and Al-sensitive cultivars of five plant species (rice, maize, pea, wheat, and sorghum). No correlation was found between the differences in Al tolerance and the cation exchange capacity of cell walls isolated from root-tips (0–1 em). Preliminary exposure to Al for 1 h was sufficient to inhibit subsequent root re-elongation in an Al-free solution, and the inhibitory effect was more pronounced in the Al-sensitive cultivars than in the Al-tolerant ones. Together with the inhibition of root re-elongation, the PM of the root-tip cells of all the Al-sensitive cultivars was more permeabilized than that of the Al-tolerant cultivars, based on the FDA-PI fluorescence staining technique. Exposure for 30 min to Al treatment at 100 µM significantly increased the PM permeability of protoplasts isolated from the root-tips for the Al-sensitive pea cultivar placed in a moderately hypotonic medium. Protoplasts from root-tip portions of all the Al-sensitive cultivars took up more Al than those of the Al-tolerant ones when treated with 100 pM Al under isotonic conditions for 30 min. The co-existence of DNP or hypotonic conditions led to a larger increase of Al uptake by the protoplasts from Al-sensitive maize cultivars. These results suggest that Al ions rapidly alter the PM of the root-tip portion in the Al-sensitive cultivars, irrespective of plant species, resulting in an increase of the PM permeability.     

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...     

Sulfonylurea-resistant biotypes of Monochoria vaginalis generate higher ultraweak photon emissions than the susceptible ones

All living organisms spontaneously generate ultraweak photon emissions, which originate from biochemical reactions in cells. Current research uses the ultraweak photon emission from organisms as a novel indicator in nondestructive analyses of an organisms living state. This study indicates that ultraweak photon emissions from Monochoria vaginalis are different between resistant biotypes (R) to sulfonylurea (SU) and susceptible biotypes (S). In SU-R biotypes, distinct increases in photon emissions were observed, but there was little increase in SU-S biotypes. In addition, photon emissions from the resistant biotypes of M. vaginalis were suppressed by treatment with P450 inhibitors. This suggests that cytochrome P450 monooxygenase, which plays a crucial role in the metabolic detoxification of SUs, could be associated with the generation of ultraweak photon emissions. Ultraweak photon emissions have a potential use in a novel diagnosis system as an indicator in a nondestructive testing of weeds resistant to SUs.     

Selective staining and visualization of hyphal sheath of a white-rot fungus <Emphasis Type="Italic">Phanerochaete crassa</Emphasis> WD1694 with phloxine B

The hyphal sheath is a morphological feature of many kinds of fungi. Although the fine structures of the sheath have been studied in detail by a number of electron microscopy techniques, the function and physiology of the hyphal sheath are not yet clarified. One reason for this is that the hyphal sheath is a colorless, mucilaginous, and delicate material so that it is not easily identified. We developed a simple method to visualize and identify the hyphal sheath of the white-rot fungus Phanerochaete crassa WD1694. The small mycelial pellets in shaken liquid cultures of P. crassa WD1694 were stained directly with phloxine B. Both the hyphae and the hyphal sheath that filled the gaps between each of the hyphae were visualized and observed by light microscopy. The stained hyphae were further studied by transmission electron microscopy, atomic force microscopy, and fl uorescence microscopy. Based on these observations, we confirmed that the staining of the hyphae was also due to the presence of the hyphal sheath that closely covered the fungal cell wall. These results clearly showed that the hyphal sheath was selectively stained with phloxine B and could be observed and identified by conventional light microscopy. Part of this report was presented at the 50th Lignin Symposium, Nagoya, October 2005     

Asexual fungus <Emphasis Type="Italic">Verticillium dahliae</Emphasis> is potentially heterothallic

Verticillium dahliae, a soilborne plant pathogen, causes wilt disease in many important crops. We reported previously that the mating type gene MAT1-2-1 is spread to isolates of this asexual fungus. However, we did not determine whether V. dahliae is homothallic or heterothallic because the opposite mating type gene, MAT1-1-1, had not been identified. In the present study, we identified the MAT1-1-1 gene from an isolate lacking MAT1-2-1 and the mating type idiomorphs of V. dahliae. Each isolate we tested contained either the MAT1-1 or MAT1-2 idiomorph, indicating that the asexual fungus V. dahliae is potentially heterothallic.     

罗勒在盐胁迫条件下水分生理及精油含量的变化

本研究旨在寻找增加芳香植物罗勒(Ocimum basiicum L)的次生代谢产物(精油)的有效途径,对罗勒生长过程中制造一种盐分压力的环境胁迫的手段进行了尝试性研究。用本研究设计的高浓度的复合盐配方处理的结果表明虽然在盐分胁迫下的罗勒水势降低,气孔阻力加大,蒸腾速度减弱,但没有对罗勒的生物量产生大的影响,相反却提高了精油含有率。     

Comparative study of the Nicotiana species with respect to water deficit tolerance during early growth

Sixty Nicotiana species were examined for tolerance against various osmotica for seed germination and seedling growth in vitro. The species showed a wide variety of tolerance, and based on the results of the in vitro tests, 31 species were selected and further evaluated for salt and drought tolerance in a glasshouse. The degrees of tolerance of germination among the 57 species toward NaCl were approximately related to those toward mannitol, indicating that the osmolarity plays a majorrole in seed germination. However, the responses during the seedling growth differed in NaCl and mannitol or drought, and there was no correlation between salt and drought tolerance. Based on the responses in vitro and in the glasshouse, N. paniculata and N. excelsior were selected as the salt tolerant species, and N. arentsii as the salt sensitive species. The degrees of accumulation of dry matter and of Na⁺ in the leaves were different in the two tolerant species; during NaCl treatment, N. paniculata and N. arentsii accumulated less dry matter relative to the control plants than N. excelsior, and N. paniculata accumulated more Na⁺ in its leaves than N. excelsior and N. arentsii. It is assumed that the two salt tolerant species have different mechanisms for tolerance to the salt. This revised version was published online in July 2006 with corrections to the Cover Date.     

Spinal epidural empyema concurrent with sequestrum in a cat: a case report

A 5-month-old intact female mixed cat presented with repetitive paraplegia and drainage of pus from the back despite continuous antibiotic medication. Neurologic examination was consistent with below T3-L3 myelopathy. Computed tomography and magnetic resonance imaging revealed a contrast-enhanced mass in the L1-3 spinal canal, and bone fragments in the T13 and L1 spinal canal. Spinal epidural empyema was suspected, and hemilaminectomy was performed for T12-L2 on the right side and T11-12 on the left side. Bone fragments were diagnosed as sequestrum infected with Bacteroides sp. The cat recovered enough to ambulate next day. One month after surgery, there was no deficit in neurological function. This is the first report of spinal epidural empyema concurrent with sequestrum in a cat.     

Oral flora of mongrel and beagle dogs with periodontal disease

The plaque flora was studied in adult mongrel and beagle dogs with periodontal disease. Gingival plaque from maxillary premolars was removed and cultured on various growth media. The flora in all dogs was composed of mostly anaerobic gram negative rods. Bacteroides asaccharolyticus was found in the highest proportion of plaque samples from mongrel dogs, and decomposed hydrogen peroxide suggesting catalase activity. Fusobacterium nucleatum was found in higher proportion in the plaque of beagle dogs as compared to B. asaccharolyticus. With the increasing numbers of obligative anaerobic gram negative organisms such as B. asaccharolyticus, the proportions of Streptococcus, Enterococcus and Staphylococcus decreased in the dogs with periodontal disease. The salivary flora was different from the plaque flora of the dogs with periodontal disease. It was constant regardless with the disease. The salivary flora of beagle dogs with the healthy gingiva was different from that of mongrel dogs. Enterococcus, Lactobacillus, Eubacterium and black-pigmented Bacteroides (BPB, mainly B. asaccharolyticus) were higher proportion in the flora of beagle dogs as compared to mongrel dogs, while Fusobacterium, Enterobacteriaceae, yeast and molds were lower in the flora. The results reveal that B. asaccharolyticus and F. nucleatum are common pathogens and uniquely contribute to the development of gingival inflammation in dog.