高效液相色谱法测定大豆胚轴中单糖链大豆皂甙的含量

大豆皂甙具有多种药理作用,而对大豆制品中各类皂甙的定量分析是研究大豆皂甙药理作用的基础.采用高效液相色谱-差示折光(HPLC-dRI)检测法测定单糖链大豆皂甙的含量.色谱条件为:ODS-AM-303色谱柱(YMC,4.6 mm×250 mm,5μm),柱温40℃,合0.1%三氟乙酸的乙腈-水(40:60)为流动相,流速1mL min-1.Ba、Bb、Bd、Be、αg和βg分别在2.24～11.2、2.35～11.8、1.58～7.92、2.01～10.1、1.38～6.88和1.62～8.12μg范围内线性关系良好,平均回收率分别为92.5%、93.8%、94.1%、95.8%、93.4%和94.2%,RSD为3.22%、3.18%、4.01%、3.53%、4.07%和4.28%.该方法准确度高,重现性好,适用于大豆皂甙样品中各类皂甙的测定.     

Complete Nucleotide Sequence of Ryegrass Mottle Virus : A New Species of the Genus Sobemovirus

The genome of Ryegrass mottle virus (RGMoV) comprises 4210 nucleotides. The genomic RNA contains four open reading frames (ORFs). The largest ORF 2 encodes a polyprotein of 947 amino acids (103.6 kDa), which codes for a serine protease and an RNA-dependent RNA polymerase. The viral coat protein is encoded on ORF 4 present at the 3′-proximal region. Other ORFs 1 and 3 encode the predicted 14.6 kDa and 19.8 kDa proteins of unknown function. The consensus signal for frameshifting, heptanucleotide UUUAAAC and a stem-loop structure just downstream is in front of the AUG codon of ORF 3. Analysis of the in vitro translation products of RGMoV RNA suggests that the 68 kDa protein may represent a fusion protein of ORF 2-ORF 3 produced by frameshifting. The protease region of the polyprotein and coat protein have a low similarity with that of the sobemoviruses (approximately 25% amino acid identity), while the RNA-dependent RNA polymerase region has particularly strong similarity (54 to 60% of more than 350 amino acid residues). The sequence similarities of RGMoV to the sobemoviruses, together with the characteristic genome organization indicate that RGMoV is a new species of the genus Sobemovirus. Received 28 June 2000/ Accepted in revised form 14 November 2000     

Eremothecium ashbyi causes soybean yeast-spot and is associated with stink bug, Riptortus clavatus

Many fusiform ascospores observed on soybean seeds with yeast spot disease symptoms differed significantly from those of Eremothecium coryli, the known causal agent of yeast spot disease in soybean. On the basis of morphological and physiological characteristics and sequence data of the internal transcribed spacer regions including the 5.8S rDNA and D1/D2 regions of 26S rDNA, this fungus was identified as E. ashbyi. Pathogenicity of E. ashbyi was confirmed by reinoculation test. This report is the report on E. ashbyi causing soybean yeast spot disease. In addition, this study showed that E. ashbyi was transmitted by the stink bug, Riptortus clavatus, as was E. coryli, the two Eremothecium yeasts may have been acquired when the stink bug fed on infected soybeans and overwintered in this insect species. The nucleotide sequence data reported are available in the GeneBank/EMBL/DDBJ database as accessions AB294407 to AB294412 for E. ashbyi EA1, EA7 and EA11.     

Quantitative trait locus analysis for days-to-heading and morphological traits in an RIL population derived from an extremely late flowering F<Subscript>1</Subscript> hybrid of sorghum

The hybrid vigor typical of F₁ cultivars is used to boost biomass production of sorghum (Sorghum bicolor (L.) Moench). The high dry-matter yielding F₁ cultivar Kazetachi uniquely shows extremely late flowering and a long culm, and is greatly different from its parents. We investigated the genetic mechanisms underlying these phenotypes by quantitative trait locus (QTL) analysis of recombinant inbred lines derived from a male-fertile line and a restorer line and grown in 3 years. QTL analysis for six traits (days-to-heading, culm length, culm width, culm number, panicle length, panicle number) revealed that the unique phenotypes of the F₁ plants were controlled by the genetic combination of 12 or more QTLs detected in at least 2 years. Two putative QTLs for days-to-heading (qDH1 on SBI-01 and qDH6 on SBI-06) would strongly affect the other phenotypes because of their co-localization with QTLs for other traits, as supported by significant phenotypic correlations. These QTLs would be useful for understanding the association of plant type with biomass production in sorghum.     

The determination of 1,2-dicarboxylate structures in humic acid by fluorescein formation

To detect and quantify 1,2-dicarboxylate structures in humic acid, a chemical reaction forming fluoresceins from 1,2-dicarboxylates and resorcinol was tested. Resorcinol reacted with humic acid to form products having absorption maxima at about 490 nm. A procedure was then developed for quantitative analysis of the radicals. Eight humic acid samples tested contained 0.4–1.0 mmol/g of 1,2-dicarboxylate structures. The 1,2-Dicarboxylates detected in humic acid were considered as ophthalate homologs.     

Oxidative deamination of benzylamine and lysine residue in bovine serum albumin by green tea, black tea, and coffee

Oxidative deamination by various polyphenolic compounds is presumed to be due to the oxidative conversion of polyphenols to the corresponding quinones through autoxidation. Here we examined the oxidative deamination by the polyphenol-rich beverages green tea, black tea, and coffee at a physiological pH and temperature. Green tea, black tea, and coffee extracts oxidatively deaminated benzylamine and the lysine residues of bovine serum albumin to benzaldehyde and alpha-aminoadipic delta-semialdehyde residues, respectively, in sodium phosphate buffer (pH 7.4) at 37 degrees C in both the presence and absence of Cu2+, indicating the occurrence of an amine (lysyl) oxidase-like reaction. We also examined the effects of pH and metal ions on the reaction. The possible biological effects of drinking polyphenol-rich beverages on human are also discussed.     

Role of Cylindrosporium-type conidia of Mycosphaerella pomi (Pass.) Lindau: cause of Brooks fruit spot of apple, as an infection source in apple orchards

Ascospores of Mycosphaerella pomi, the pathogen of Brooks fruit spot of apple, were produced in pseudothecia on previously infected and overwintered apple leaves from late April through early August in Aomori Prefecture, Japan. In June 2003, the ascospores were germinating and producing Cylindrosporium-type conidia on apple fruit and leaf surfaces in an orchard. After ascospores were sprayed on apple leaves, Cylindrosporium-type conidia developed on the leaf surfaces. Such Cylindrosporium-type conidia caused typical symptoms of Brooks fruit spot on apple trees after inoculations. These results suggested that the Cylindrosporium-type conidia also serve as an infection source, in addition to the ascospores, for Brooks fruit spot in apple orchards.     

<Emphasis Type="Italic">Eremothecium coryli</Emphasis> and <Emphasis Type="Italic">E.</Emphasis><Emphasis Type="Italic">ashbyi</Emphasis> cause yeast spot of azuki bean

Yeast-like fungi were isolated from lesions on azuki bean (cv. Shin-Kyotodainagon) seeds that had been sucked by bean bugs in Kyoto Prefecture, Japan. On the basis of morphological and physiological characteristics and sequence data of the internal transcribed spacer (ITS) regions including the 5.8S rDNA, these yeasts were identified as Eremothecium coryli and E. ashbyi. Pathogenicity of those yeasts was confirmed by a reinoculation test. To our knowledge, this is the first report of the occurrence of yeast spot in azuki bean in Japan. The nucleotide sequence data reported are available in the GeneBank/EMBL/DDBJ database as accessions AB478291–AB478309 for E. coryli AZC1–19 and AB478310–AB478317 for E. ashbyi AZA1–8.     

Extraction of active aluminum from acid soils in Japan with different reagents

The paper deals with methods of determining active aluminum in acid soils. Extraction reagents examined were 4 acids, 4 salts, and 11 compounds of chelating agents. The effects of different conditions, such as pH, temperature, shaking time and the ratio of solution to soil were observed. Barium salicylate solutions, in which the normal concentration of barium and the molar concentration of salicylate were 1.0 and 0.1 respectively, were found promising as extractants. Initial pH of the solution, shaking time and the ratio of solution to soil were set at 7.0, 2 hours and 50:1, respectively. Ammonium salicylate and ammonium EDTA also extracted active aluminum but amounts varied according to different conditions. The most promising procedure was applied to a few kinds of soils and to soil treated with either lime or phosphate. The amounts of aluminum extracted from soils high in humus were larger than those from soils low in humus. Liming or phosphate application decreased the amounts of aluminum extracted.     

多花黑麦草斑驳病毒基因组克隆与序列分析

 多花黑麦草斑驳病毒(Ryegrass mottle virus,RGMoV)属南方菜豆花叶病毒属,是牧草病毒病的重要病原。利用反转录技术合成和扩增了RGMoV RNA的cDNA。将cDNA克隆在载体pUC18上,对RGMoV的基因组RNA作序列分析。RGMoV RNA是一个正义单链RNA分子,全长4 210个核苷酸,包含4个开放阅读框架5'非翻译区包含99个核苷酸,3'非翻译区有198个核苷酸。RGMoV ORF的结构和南方菜豆花叶病毒以及水稻黄斑病毒的结构一样。ORF₁编码1个14.6 kD的蛋白质,这个蛋白质的功能还不清楚;ORF₂的产物由947个氨基酸组成,分子量为103.6 kD;ORF₃编码1个19.8 kD的蛋白质;ORF4编码1个25.6 kD的蛋白质,通过N末端氨基酸分析,确认ORF4为病毒外壳蛋白。RGMoV RNA的全序列以及染色体结构已被GenBank登录,登录号分别为AB040446和NC_003747。