Nephrocalcinosis formation by soy isoflavones in male rats

Isoflavones (IFs), found in the form of both aglycones and glucosides in soybean foods, induce weak estrogenic activities. Although IFs have a number of health benefits, it was previously reported that IFs cause nephrocalcinosis (NC) in the kidney of male Fischer 344 (F344) rats. The present study aims to elucidate the safety of IFs by focusing on IF-induced NC formation in rats. Fermented soybean extract (FSE) containing 420 mg/g isoflavone aglycones was orally administered to male F344 and Sprague-Dawley (SD) rats for 28 days. FSE induced NC formation in the kidney of F344 rats, but not in SD rats. However, absorption of IFs did not differ between F344 and SD rats. NC formation and its severity of FSE were histologically compared with those of soybean extract (SE) containing 518 mg/g isoflavone glucosides in F344 rats. There were no differences in the number of NC formations and the extent of calcium deposit between FSE and SE groups. To examine the dose effect of FSE on NC formation, doses of 20, 140, or 1000 mg/kg FSE were administered to F344 rats for 90 days. NC formation was observed in the 140 and 1000 mg/kg groups. These results indicated that a high dose of oral administration of IFs induced NC formation depending on the strain of rat.     

P and N deficiency change the relative abundance and function of rhizosphere microorganisms during cluster root development of white lupin (Lupinus albus L.)

We studied microbe-plant interactions of white lupin, a cluster root-forming plant, under low P and N conditions to examine increased nutrient acquisition by plants either by a shift to a more specialized microbial community or changes in microbial enzyme production. White lupin plants were grown in rhizoboxes filled with either P- or N-deficient soil; fertilized soil was used as control. After cultivation of plants in a glasshouse for 41 d, plant growth (shoot and roots) and P and N accumulation in shoots were measured. Microbial functions were analyzed by P- and N-cycling enzymes. The microbial community structure was estimated by fingerprinting (denaturing gradient gel electrophoresis) and sequencing techniques. P deficiency induced the released citrate and acid phosphomonoesterases from cluster roots and stimulated the production of microbe-derived alkaline phosphomonoesterase in the rhizosphere. P deficiency decreased microbial diversity in the cluster root rhizosphere. Increased relative abundance of Burkholderiales in the rhizosphere of P deficient plants might be responsible for the degradation of different organic P fractions such as phytates. N deficiency induced an increase of the number of nodules and P concentration in shoot as well as roots of white lupin. We clarified that high release of citrate from cluster roots might be the preferred mechanisms to meet the P demand of nodulated plants under N deficiency. In addition, the high abundance of Rhizobiales and Rhodospirillales in the rhizosphere of cluster roots showed that the importance of N-fixing microorganisms under N deficiency. The contribution of rhizosphere microorganisms due to similar activities of N-cycling enzymes under the two different N treatments is less important for N nutrition of plants. Further understanding of the regulation of cluster roots under N-deficiency will provide new information on the interactions between P and N nutrition.     

Overexpression of the LASAP2 gene for secretory acid phosphatase in white lupin improves the phosphorus uptake and growth of tobacco plants

Secretion of acid phosphatase (APase) from the roots to take up phosphorus (P) is a well-known strategy of plants under P-deficient conditions. White lupin, which shows vigorous growth in low-P soils, is noted for its ability to secrete APase under P-deficient conditions. The APase secreted by white lupin roots is stable in soil solution and shows low substrate specificity, suggesting that genetic modification of plants using the APase gene LASAP2 might improve their ability to use organic P. The objective of the present study was to evaluate the potential of LASAP2 transgenic plants to increase organic P utilization. Dry matter production and P accumulation were higher in LASAP2 transgenic tobacco plants grown in gel media containing soluble phytate as the sole P source than in wild-type tobacco plants. Phosphorus uptake by the transgenic plants also increased in soil culture conditions. LASAP2 was apparently more effective in the liberation of organic P, including phytate, in the soil than the native tobacco APase. Thus, the enzymatic stability of LASAP2 in the soil appears to be an important factor for P acquisition.     

Can stumps tell what people want: Pattern and preference of informal wood extraction in an urban forest of Nairobi, Kenya

Detailed patterns and preferences of informal wood extraction were investigated in an urban forest used by slum inhabitants of Nairobi, Kenya, as such information determines the sustainability of resource use. Instead of asking the people what they had secretly cut, a survey was conducted of the stumps and trees left in the forest to (i) evaluate how accessibility and patrolling affected spatial patterns of resource use, and to (ii) estimate a broad spectrum of species and species-specific size preferences. Both probability and size of cutting increased with better accessibility (represented by distance from the slum), and stump size exceeded that of living stem size around 1.7 km from the slum, which suggested magnified impact of tree cutting near the slum. Patrolling (represented by distance from ranger stations) had little effect in reducing the probability of cutting but was effective in reducing cut size. With the use of random effect models, a broad species preference spectrum (including less abundant and non-preferred species) was estimated, which indicated trends in vegetation change. Smaller stems were preferred for most species presumably used for domestic fuelwood, but major exploitation of large Brachylaena huillensis stems traded in the woodcarving industry was also revealed. Such detailed information on informal wood use can help forest managers to understand threats to the forests as well as the needs of local communities. This is a first step to redefining ‘acceptable’ resource use by the local community for their increased role and responsibility in sustainable forest management, especially when conventional controls of informal activities (i.e. exclusion and penalty) are not functioning well.     

Effect of simulated acid rain on the growth of soybean

Soybean seedlings (Glycine max) grown in a glasshouse were exposed to simulated acid rain using a solution of deionized water containing sulfate, nitrate and chloride in concentrations and proportions equivalent to those in ambient rain water. Plants were subjected to acid rain treatment twice a week during the growing season, for a 1 hr period at a rate of 5 mm hr^?1. When the acid rain was below pH 3.0, visible symptoms developed in the young trifoliate leaves. However, at a pH above 3.0 there was no evidence of visible leaf injury; also tissue dry weights and leaf areas were not affected even after 7 weeks of exposure. The number of root nodules in plants exposed to acid rain at pH 4.0 tended to be higher than those of control plants maintained at pH 5.6, but decreased subsequently with decreasing pH. Based on our results current ambient levels of rain acidity in Japan should not have an adverse impact on seedling growth in soybean.     

Effects of aromatic ring type on reactions subsequent to the <Emphasis Type="Italic">β</Emphasis>-<Emphasis Type="Italic">O</Emphasis>-4 bond cleavage of non-phenolic lignin model compounds under alkaline pulping conditions

The reaction products of an alkaline treatment of non-phenolic β-O-4-type lignin model compounds (C₆–C₂-type) consisting of p-hydroxyphenyl (H), guaiacyl (G), and/or syringyl (S) nuclei were identified and quantified. This was performed to examine how the type of H, G, or S nucleus affect the reaction product profiles. The major identified and quantified reaction products were phenol derivatives that were liberated from the aryl sides of the β-O-4 ether bonds of the lignin model compounds. Other products included derivatives of phenylethane-1,2-diol (glycol-type), benzaldehyde, and acetophenone, which originated from the alkyl sides of the β-O-4 ether bonds of the lignin model compounds. Although the type of aromatic nucleus of the aryl side of the β-O-4 ether bond of the lignin model compounds did not significantly affect the profile of the reaction products, the type of the alkyl side nucleus was influential. The glycol-type compound was the exclusive major reaction product when the S nucleus was on the alkyl side of the β-O-4 ether bond. On the other hand, when the H or G nucleus was present, a benzaldehyde derivative was the other major reaction product.     

人工合成甘蓝型油菜的繁育特性与试管繁殖

通过甘蓝品种(2n=18，CC)与白菜品种(2n=20，AA)杂交并借助胚珠培养和染色体加倍，获得一系列人工甘蓝型油菜新品系。对18个人工合成甘蓝型油菜新品系的花粉育性、自交结实性、异交结实性等研究表明，人工油菜品系花期自交不结实或结实率很低。蕾期自交一朵花平均获3．6粒种子，平均结角率为19．7％。但是，人工甘蓝型油菜无论作父本还是作母本与天然甘蓝型油菜杂交的结实率都较高。以人工油菜作父本与天然油菜杂交。42个组合平均杂交一朵花获得10．3粒杂交种子；以人工油菜作母本与天然油菜杂交，15个组合平均杂交一朵花获得8．5粒杂交种子。分析结果表明。本试验的人工油菜品系具有很强的自交不亲和性，蕾期自交结实率也较低，但对异交结实影响不大，因此可以直接用于杂种生产。试验对自交结实特别困难的5个人工甘蓝型油菜新品系进行了试管繁殖，采取子叶、下胚轴和茎尖联合培养方式。22株无菌苗经过2个月快繁，获得260株苗。平均繁殖系数为12．4。不同基因型繁殖系数差异较大。变幅为3．3～21．0。     

Arrhythmogenic right ventricular cardiomyopathy coincided with the cardiac fibrosis in the inner muscle layer of the left ventricular wall in a boxer dog

A 7-year-old female boxer dog died suddenly without any clinical signs. It was suspected that the dog had arrhythmogenic right ventricular cardiomyopathy (ARVC) due to ventricular premature complexes and ventricular tachycardia at 3 years of age. The final diagnosis of ARVC was confirmed by histological characteristics, such as loss of cardiocytes and fibrofatty replacement, occurring in the right and left ventricular walls. In the cardiocytes, non-lipid vacuoles were observed. Cardiac fibrosis and intimal thickening of the small arteries occurred without fatty replacement in the inner muscle layer including the papillary muscles of the left ventricular wall. This paper describes the pathomorphological details of an ARVC case with coincidental cardiac fibrosis in the inner muscle layer of the left ventricular wall.     

Individual-based measurement and analysis of root system development: case studies for <Emphasis Type="Italic">Larix gmelinii</Emphasis> trees growing on the permafrost region in Siberia

We present results of individual-based root system measurement and analysis applied for Larix gmelinii trees growing on the continuous permafrost region of central Siberia. The data of root excavation taken from the three stands were used for the analyses; young (26 years old), mature (105 years old), and uneven-aged over-mature stand (220 years old). In this article, we highlight two topics: (1) factors affecting spatio-temporal pattern of root system development, and (2) interactions between aboveground (i.e., crown) and belowground (i.e., root) competition. For the first topic, the detailed observation of lateral roots was applied to one sample tree of the overmature stand. The tree constructed a superficial (<30 cm in depth) and rather asymmetric root system, and each lateral root expanded mainly into elevated mounds rather than depressed troughs. This indicated that spatial development of an individual root system was largely affected by microtopography (i.e., earth hummocks). For these lateral roots, elongation growth curves were reconstructed using annual-ring data, and annual growth rates and patterns were compared among them. The comparison suggested that temporal root system development is associated with differences in carbon allocation among the lateral roots. For the second topic, we examined relationships between individual crown projection area (CA) and horizontal rooting area (RA) for the sample trees of each stand. RA was almost equal to CA in the young stand, while RA was much larger (three or four times) than CA in the mature and overmature stands. Two measures of stand-level space occupation, crown area index (aboveground: CAI; sum of CAs per unit land area) and rooting area index (belowground: RAI; sum of RAs), were estimated in each stand. The estimates of RAI (1.3–1.8 m² m₋₂) exceeded unity in all stands. In contrast, CAI exceeded unity (1.3 m² m₋₂) only in the young stand, and was much smaller (<0.3 m² m₋₂) in the two older stands. These between-stand differences in RAI–CAI relationships suggest that intertree competition for both aboveground and belowground spaces occurred in the young stand, but only belowground competition still occurred in the two older stands. Based on this finding, we hypothesized that competition below the ground may become predominant as a stand ages in L. gmelinii forests. Methodological limitations of our analysis are also discussed, especially for the analysis using the two indices of space occupation (CAI, RAI).