Detection of the regions of phytosiderophore release from barley roots

Abstract

We devised a method to detect regions of phytosiderophore release from barley (Hordeum vulgare cv. Minorimugi) roots. Plants were grown in Fe-sufficient (+Fe) or Fe-deficient (?-Fe) water cultures for 14 d in a phytotron. Intact or excised roots were sampled and put between two sheets of filter papers just after the onset of the light period. The filter papers with roots were wrapped with vinyl film to avoid drying out and covered with aluminum foil to shade. The roots between the filter paper were kept in the phytotron for 4 h and phytosiderophores (PS) released from roots were absorbed by the filter paper. Then, the shape of the roots was preserved by photocopy and PS released on the filter paper were visualized by the method employed for detecting PS on thin layer chromatography (TLC). Gelatinous Fe solubilizing activity was employed for detecting PS on the filter paper. Released PS were detected as white spots on the orange-colored background and the regions of PS release from the roots were visible on the filter paper. It was evident that the apical zones of roots were the main regions of PS release. It was apparent that a distinct primary root newly formed on the basal parts had higher activity to release PS than the other roots of ?Fe plants. It was also shown that apical root zones of +Fe plants released PS.     

Bilirubin-binding protein in the serum of spawning-migrating chum salmon,Oncorhynchus keta: Its identity with carotenoid-carrying lipoprotein

The serum carotenoid level gradually increased during the spawning migration of chum salmon (Oncorhynchus keta). Zeaxanthin, a yellowish carotenoid, was detected in the serum of spent males, while astaxanthin was a main carotenoid in the serum of males and females at other developmental stages. A high bilirubin level was found in the serum of spent males; the serum of spent male was yellow in colour due to the presence of zeaxanthin and bilirubin, although the serum of the other fish was bright orange.Three types of carotenoid-carrying lipoprotein such as low density lipoprotein, high density lipoprotein (HDL) and very high density lipoprotein fractions were present in the serum. Carotenoid-carrying lipoprotein from the HDL fraction became a main component during spawning migration. The serum bilirubin from the spent male salmon was distributed in the HDL fraction. Because bilirubin, as well as carotenoids, were present in the HDL fraction, the carotenoid-carrying lipoprotein from the HDL fraction was identical with bilirubin-binding protein in the serum of spent males. This carrier lipoprotein had two subunits (molecular weight 24,000 and 12,000); no disulfide bond was detected between the two subunits.     

Distinguishing Cattle Foraging Activities Using an Accelerometry-Based Activity Monitor

Various sensors and analytic tools have been developed to assist with the collection and analysis of data regarding the activities of animals at pasture. We tested an accelerometry-based activity monitor, the Kenz Lifecorder EX (LCEX; Suzuken Co Ltd, Nagoya, Japan), to differentiate between foraging and other activities of beef cows in a steeply sloping pasture. Logistic regression (LR) and linear discriminant analysis (LDA), two of the most widely used techniques for distinguishing animal activities based on sensing device information, were employed in the analysis. An LCEX device was worn on a collar by each of four cattle over the course of 4 d, during which time the activity (foraging, resting, ruminating, walking, and grooming) of each cow was recorded by trained observers at 1-min intervals for a total of 15 h. LR and LDA were applied to the LCEX and observer data to distinguish between foraging and other activities. Overall, a more accurate measure was obtained by LDA (90.6% to 94.6% correct discrimination among cows) than by LR (80.8% to 91.8% correct discrimination). The threshold LCEX value for distinguishing between foraging and other activities varied among cows, and the correct discrimination rate for the pooled data set was 92.4% for LDA and 85.6% for LR. Based on individual cow LDA, the time spent foraging averaged between 443 and 475 min · d^?1. Our results indicated that LCEX can be used to identify the foraging activity of cattle.     

Seasonal and spatial variation of nitrogen dynamics in the litter and surface soil layers on a tropical dry evergreen forest slope

Seasonal and spatial variability of litterfall and NO₃⁻ and NH₄⁺ leaching from the litter layer and 5-cm soil depth were investigated along a slope in a tropical dry evergreen forest in northeastern Thailand. Using ion exchange resin and buried bag methods, the vertical flux and transformation of inorganic nitrogen (N) were observed during four periods (dry, early wet, middle wet, and late wet seasons) at 15 subplots in a 180-m × 40-m rectangular plot on the slope. Annual N input via litterfall and inorganic N leached from the litter layer and from 5-cm depth soil were 12.5, 6.9, and 3.7 g N m⁻² year⁻¹, respectively, whereas net mineralization and the inorganic N pool in 0–5-cm soil were 7.1 g N m⁻² year⁻¹ and 1.4 g N m⁻², respectively. During the early wet season (90 days), we observed 82% and 74% of annual NO₃⁻ leaching from the litter layer and 5-cm soil depth, respectively. Higher N input via leaf litterfall in the dry season and via precipitation in the early wet season may have led to higher NO₃⁻ leaching rate from litter and surface soil layers during the early wet season. Large spatial variability in both NO₃⁻ vertical flux and litterfall was also observed within stands. Small-scale spatial patterns of total N input via litterfall were significantly correlated with NO₃⁻ leaching rate from the surface soil layer. In tropical dry evergreen forests, litterfall variability may be crucial to the remarkable seasonal changes and spatial variation in annual NO₃⁻ vertical flux in surface soil layers.     

Soil depth and soil water regime in a catchment where tropical dry evergreen and deciduous forests coexist

In several areas in Northeast Thailand, evergreen and deciduous forests coexist under uniform climatic conditions. To identify the factors that determine the distribution of these different forest types, we compared soil depth and soil physical properties between evergreen and deciduous forests, and monitored soil moisture conditions for a year in both forest types at the Sakaerat Environmental Research Station. The soil was significantly deeper under the evergreen forests (mean 97 cm) than under the deciduous forest (mean 64 cm). The soil under the evergreen forests retained much more water throughout the year than the soil under the deciduous forest, and there was also a clear tendency for the evergreen forests to occur in ravine areas, regardless of soil depth. It is possible that the evergreen trees can maintain transpiration during the dry season on thicker soils or in ravine areas, whereas shallower soils cannot provide enough water for these trees to maintain their evapotranspiration during the dry period. From the present study, we showed that soil water availability could be a significant factor determining the distribution of the deciduous and evergreen forests in our catchments.     

Changes in peripheral leukocyte populations of weak calf syndrome of Japanese black calves

To clarify the cellular immune condition in Japanese Black (JB) calves with a weak syndrome, peripheral leukocyte populations were analyzed by flow cytometry. Twenty JB calves were divided into two groups based on clinical observations; one group of calves was weak, because they had experienced an onset of diarrhea within 3 days after birth and needed treatment (Group 1 ;n=10), and the other group of calves was healthy (Group 2; n=10). With regard to leukocyte populations, CD8(+) cells and gamma delta T cells in Group 1 were markedly lower than those in Group 2 during the experimental periods. It is possible that immune-insufficiency might be based on T lymphocyte function in weak syndrome JB calves during the growth process.     

Detection of radiation-induced apoptosis using the comet assay

The electrophoresis pattern of apoptotic cells detected by the comet assay has a characteristic small head and spread tail. This image has been referred to as an apoptotic comet, but it has not been previously proven to be apoptotic cells by any direct method. In order to identify this image obtained by the comet assay as corresponding to an apoptotic cell, the frequency of appearance of apoptosis was examined using CHO-K1 and L5178Y cells which were exposed to gamma irradiation. As a method for detecting apoptosis, the terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay was used. When the frequency of appearance of apoptotic cells following gamma irradiation was observed over a period of time, there was a significant increase in appearance of apoptosis when using the TUNEL assay. However, there was only a slight increase when using the comet assay. In order to verify the low frequency of appearance of apoptosis when using the comet assay, we attempted to use the TUNEL assay to stain the apoptotic comets detected in the comet assay. The apoptotic comets were TUNEL positive and the normal comets were TUNEL negative. This indicates that the apoptotic comets were formed from DNA fragments with 3'-hydroxy ends that are generated as cells undergo apoptosis. Therefore, it was understood that the characteristic pattern of apoptotic comets detected by the comet assay corresponds to cells undergoing apoptosis.