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81.
Khurram Bashir Yasuhiro Ishimaru Hugo Shimo Yusuke Kakei Takeshi Senoura Ryuichi Takahashi 《Soil Science and Plant Nutrition》2013,59(6):803-812
Iron (Fe) is an essential micronutrient for plants; however, despite its abundance in soils it is not readily available in neutral to alkaline soils. Plants secrete phenolics, such as protocatechuic acid (PCA) and caffeic acid (CA), to absorb and utilize precipitated apoplasmic Fe from root surfaces. However, the synthesis and secretion of phenolics have not been well characterized in plants. We have identified and characterized a rice (Oryza sativa L.) mutant with reduced amounts of PCA and CA in xylem sap and root exudates; hence we named it phenolics efflux zero 2 (pez2). PEZ2 localized to the plasma membrane in onion (Allium cepa L.) epidermal cells and transported PCA when expressed in Xenopus laevis oocytes. PEZ2 expression was observed in whole root near root tips. Similarly, strong expression was observed in leaves. In line with reduced amounts of PCA and CA in xylem sap, the xylem Fe concentration was also low in pez2 plants. These results suggest that PEZ2 is involved in solubilization of apoplasmic Fe in rice. 相似文献
82.
Tomoyuki Makino Syuichi Hasegawa Yasuhiro Sakurai Satoshi Ohno Hirokatsu Utagawa Yuji Maejima 《Soil Science and Plant Nutrition》2013,59(3):581-590
Abstract The changes in the exchangeable Mn (Ex-Mn), exchangeable Co (Ex-Co), and exchangeable Cu (Ex-Cu) contents by air-drying of soils were reported in our previous paper. The drying effect, however, was not analyzed in the field. The objective of this study was to investigate the influence of soil-drying under field conditions on Ex-Mn, Ex-Co, and Ex-Cu levels. Two paddy soils (Tsukuba and Yawara) were collected at four different soil depths (0?1, 1?5, 5?10, and 10?20 cm) under three different soil moisture conditions i.e., after harvest, after successive sunny days and after rainy days. After sunny days, Ex-Mn and Ex-Co contents in the surface soil layer markedly increased and drastically decreased after rainfall, while they remained almost unchanged in the lower soil layers. Ex-Cu contents slightly increased in the surface soil layer after sunny days. A similar tendency was observed in soil column experiments. The contents of Ex-Mn, Ex-Co, and Ex-Cu increased 12, 12, and 2 times in the upper layer of soil columns that had been sampled from the Yawara field and stored in a dark room for 8 d. The increase of the Ex-Mn and Ex-Co contents in the upper layer could not be explained by the capillary rise of soil water from the lower layers of the columns. In a soil-drying experiment under laboratory conditions, Ex-Mn and Ex-Co contents began to increase when the water content of the Yawara soil was lower than 0.09?0.13 kg kg?1. The water content of the surface soil of the Yawara field after sunny days was 0.08 kg kg?1. Ex-Cu content did not change apprecially with the water content. It is concluded that the increase of the Ex-Mn and Ex-Co levels in field surface soils after sunny days can be ascribed to soil-drying. Some of the excess Ex-Mn and Ex-Co is expected to leach down into lower layers due to rain, which may contribute to plant uptake of Mn and Co. 相似文献
83.
The aim of the present study was to examine whether the 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyl tetrazolium bromide (MTT) colorimetric assay can be applied to measurement of mitogen‐induced chicken splenocyte activation. Activation was also measured by a 3H‐thymidine uptake assay and a viable cell count assay. Optimal concentrations of mitogens and incubation periods required for maximal responses to mitogens differed between the MTT assay and the viable cell count and thymidine uptake assays. This probably reflects differences in the activities measured by the MTT assay which detects mitochondrial enzyme activity, and the thymidine uptake and viable cell count assays which detect cellular proliferation activity. The validity of the MTT assay was supported by the observation that the mitogen‐induced increase in succinate dehydrogenase activity paralleled the level of mitogen‐induced MTT formazan production. Mitogen concentrations inducing maximal formazan formation in chicken splenocytes were higher than those for chicken peripheral blood lymphocytes reported previously. Results of the present study indicate that mitogen‐induced chicken splenocyte activation could be measured by the MTT colorimetric assay, although mitogen concentrations and incubation periods required for maximal splenocyte activation differed between the MTT assay and the other two assays used in this study. 相似文献
84.
Yoshikazu TAKETA Yasuhiro NAGAI Hideki OGASAWARA Shinichiro HAYASHI Masato MIYAKE Sachi TANAKA Kouichi WATANABE Shyuichi OHWADA Hisashi ASO Takahiro YAMAGUCHI 《Animal Science Journal》2008,79(3):382-390
Myostatin (MSTN), known as growth and differentiation factor 8 (GDF-8), is a member of the transforming growth factor β (TGF-β) superfamily that negatively regulates skeletal muscle mass. Myostatin binds with high affinity to the receptor serine threonine kinase activin receptor type IIB (ActRIIB). Activins that also belong to the TGF-β superfamily, stimulate follicle-stimulating hormone production in gonadotrophs and suppress growth hormone and adrenocorticotropic hormone production in somatotrophs and corticotrophs, respectively. The aim of the present paper was therefore to clarify the endocrine action of MSTN in adenohypophysis. The present study details the expression and cellular localization of MSTN and ActRIIB in porcine anterior pituitary gland. The mRNA of MSTN and ActRIIB was consistently expressed in RT-PCR. Immunohistochemistry of MSTN and specific hormones showed that MSTN localized in thyrotrophs and gonadotrophs, in which most of the MSTN immunoreactive cells were identified as thyrotrophs. The immunostaining of ActRIIB was restricted to corticotrophs. These results indicate that MSTN was mainly produced in thyrotrophs and its receptor, ActRIIB, was restrictively contained in corticotrophs. Interestingly, thyrotrophs immunoreactive for MSTN were frequently close to corticotrophs immunoreactive for ActRIIB. The present study suggests that MSTN from thyrotrophs may regulate corticotroph function as a paracrine mediator among the porcine anterior pituitary cells. 相似文献
85.
Masafumi SHIMIZU Norikazu FUJITA Yoshiko NAKAGAWA Tomio NISHIMURA Tamotsu FURUMAI Yasuhiro IGARASHI Hiroyasu ONAKA Ryuji YOSHIDA Hitoshi KUNOH 《Journal of General Plant Pathology》2001,67(4):325-332
An endophytic actinomycete, Streptomyces sp. R-5, which had been isolated from a field-grown rhododendron plant, was used to protect rhododendron seedlings in tissue
culture from Pestalotia disease caused by Pestalotiopsis sydowiana. R-5 had intense antagonistic activity against P. sydowiana without adversely affecting the seedlings in glass flasks. A suspension of R-5 was spread on the surface of the multiplication
medium in glass flasks in which seedlings were growing. Ten days later, the 4th upper leaf of seedlings was inoculated with
P. sydowiana and incubated for 14 days. In controls untreated with R-5, substrate mycelia of P. sydowiana grew on all leaves and stems above and below the 4th leaf within 2–3 days of inoculation. Such growth resulted in the wilting
death of 54% of seedlings by 14 days. In contrast, only the inoculated leaves turned brown in ca. 90% of seedlings growing on medium treated with R-5. None of these seedlings died. Thus, treatment of the medium surface
with R-5 efficiently protects the seedlings from infection by P. sydowiana. Scanning electron microscopy revealed that substrate mycelia of R-5 grew on and beneath the cuticle of leaves of the treated
seedlings. Fluorescent microscopy showed that R-5 was also inside the leaves.
Received 8 June 2001/ Accepted in revised form 4 July 2001 相似文献
86.
87.
Yasuhiro UNO Hiroshi YAMAZAKI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(1):147-148
In cynomolgus macaques, which are widely used in drug metabolism studies, CYP2C19
(formerly known as CYP2C75) is abundantly expressed in liver, metabolizes human CYP2C
substrates and is thus an important drug-metabolizing enzyme. One of the cynomolgus
CYP2C19 alleles (p.Phe100Asn, p.Ala103Val and p.Ile112Leu) results in
substantially reduced metabolic activity and thus is an important allele in drug
metabolism studies. For this allele, a genotyping tool was developed using allele-specific
TaqMan probe. Genotyping 40 Cambodian cynomolgus macaques using this tool found 1
homozygote, 17 heterozygotes and 22 wild type animals, and the result was confirmed by
direct-sequencing. Interestingly, this allele frequency was similar to that of Chinese
cynomolgus macaques. The genotyping tool established is useful for drug metabolism studies
using cynomolgus macaques. 相似文献
88.
Young-Ha SHIN Shunta SHIRAISHI Kiyoaki NARABARA Asaki ABE Yasuhiro KONDO 《Animal Science Journal》2012,83(2):156-161
Estrogen has been reported to act on B cell genesis in the bursa of Fabricius of chick embryos. In this study, we attempted to demonstrate the hypothesis that B cell genesis is controlled by estrogen receptor (ER) in the bursal cells and steroidogenic enzymes synthesized in the bursa. We previously reported the presence of estrogen receptor α (ERα) in the bursa during the late stage of embryogenesis and an increase in the expression of ERα messenger RNA (mRNA) between the 13th day and 16th day. The number of ER-positive cells was maximal on the 16th day. In the present study, ER-positive cells in the bursa during the late stage of embryogenesis increased 4 h after β-estradiol treatment on the 14th to 18th day. The concentration of β-estradiol in the embryonic bursa increased. These results suggest that this stage of embryogenesis is critical in B cell development in the bursa in connection with the effect of estrogen treatment. Our findings also showed that the mRNA expression of five steroidogenic enzymes occurred in the bursa of chick embryos. These results suggest that estrogen is synthesized in the embryonic bursa and estrogen acts on the bursal cells in a paracrine fashion. 相似文献
89.
Yasuhiro Utsumi Shinya Koga Naoaki Tashiro Atsushi Yamamoto Yukie Saito Takanori Arima Hirokazu Yamamoto Masahiko Kadomatsu Nao Sakanoue 《Journal of Wood Science》2006,52(6):477-482
Of all plant materials used to cover the roofs of traditional Japanese buildings, Japanese cypress (Chamaecyparis obtusa) bark, hiwada, has the longest service life and has been used from ancient times. However, wood and bark properties after hiwada harvest have not been evaluated in detail. We studied whether decortication for hiwada production in winter affected xylem and phloem formation. Decorticated trees still preserved all inner bark and part of the
outer bark, and both decorticated and control trees had similar annual ring structures at all stem heights in the xylem and
phloem. In both xylem and inner bark, no significant difference in ring width at any stem height was found between annual
rings before and after decortication. Thus, this study revealed that the decortication of bark for hiwada production does not affect the formation of xylem and the inner and outer bark if decortication is carried out by highly
skilled workers in winter. 相似文献
90.
刘璨 Maxim Lobovikov Daniel Murdiyarso Hiroyasu Oka Yeo-Chang Youn Keith Barney Makoto Inoue Hariadi Kartodihardjo Pia Katila Tetsuya Saito Bintang Simangunsong Yasuhiro Yokota 吕金芝 林海燕 《绿色中国(A版)》2005,52(22):33-36
在过去的20年里,亚洲林业经历了引人注目的转型,包括从计划经济到市场经济的转变,从天然林供给木材到人工林供给木材的转变,木材替代品与非木质林产品的增加,地方分权与当地群众的参与,生态时代的发展与生态系统管理。在促进亚洲可持续森林资源管理中,市场工具、社区参与和环境服务都得到了应用。亚洲林业的转型表现出多样化,其森林、社会与环境之间的联系是丰富多彩的。 相似文献