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71.
Jorge J. Casal R. Alejandra Mella Carlos L. Ballaré Sara Maldonado 《Physiologia plantarum》1994,92(4):555-562
Etiolated Vicia faba seedlings were exposed to continuous red light to investigate whether changes in extracellular peroxidase activity were correlated in time and localization with changes in extension growth and/or lignin content in the subapical region of the epicotyl. Continuous red light: (a) increased extracellular peroxidase activity after a lag of ca 0.5 h, followed by a maximum peak after 2.5 h due to slightly acidic isoforms (pI = 6–6.5, according to isoelectrofocusing gels), a minimum after 4 h and a second maximum after 8 h due to acidic isoforms (pI=4–5), (b) increased lignin content and epicotyl resistance to bending after a lag of ca 4 h, i.e. simultaneously with changes in acidic extracellular peroxidase activity, and (c) reduced extension growth to a stable rate after a lag of ca 1 h, not coinciding with the kinetics of any of the extracellular peroxidase isoforms. These effects of continuous red light were at least partially mediated by phytochrome. Tissue printing and anatomical studies revealed red light effects on extracellular peroxidase activity and lignin content mainly in the outer cortical parenchyma. The results are consistent with the involvement of phyto-chrome-mediated effects on extracellular peroxidases (acidic isoforms) in the transduction chain leading to lignin responses to red light. 相似文献
72.
Federica Rossi Rita Baraldi Osvaldo Facini Bartolomeo Lereari 《Plant Cell, Tissue and Organ Culture》1993,32(2):145-151
The morphogenic effect of different light wavelengths on in vitro rooting of Prunus insititia GF655-2 in relation to the presence of napthaleneacetic acid (NAA) in the culture medium was investigated. Results of experiments in which plantlets were rooted in NAA enriched medium showed that the presence of auxin induced rooting even in the dark after an initial lag period. Illumination of the cultures with Red light was as effective in promoting rooting as treatment with 0.5 M NAA; Red was more active in stimulating rooting in the short term than was NAA. The pattern of root formation resulting from the addition of NAA appeared to dominate development under White, Blue and Far Red treatments. Although it was possible to correlate the rooting response to the phytochrome photoequilibrium induced by the light treatments used, there arises a possible interference of specific Blue absorbing photoreceptors.Abbreviations B
Blue
- FR
Far Red
- HIR
High Irradiance Response
- Pfr
active (far-red absorbing) form of phytochrome
- Ptot
total phytochrome
- R
Red
- W
White
- NAA
-naphtaleneacetic acid
- BA
benzyladenine
- IAA
indole 3-acetic acid 相似文献
73.
降钙素基因相关肽的研究进展 总被引:1,自引:0,他引:1
吴祥声 《氨基酸和生物资源》1994,(1)
降钙素基因相关肽(CGRP)是由37个氨基酸残基构成的生物活性多肽,与降钙素(CT)源子一个共同的基因。CGRP分布广泛,具有很强的血管扩张、降低血压以及心肌正性肌力作用等,并参与心血管系统稳态的调节。目前,CGRP已能人工合成,将为某些心血管疾病如高血压、心肌缺血、痉挛性或闭塞性周围血管疾病等的治疗提供一条崭新的途径。 相似文献
74.
再生稻褐飞虱为害损失测定和防治指标的研究 总被引:1,自引:0,他引:1
在福建,褐飞虱是再生稻的重要害虫,中进行了再生稻褐飞虱为害损失的测定,并对褐飞虱为害再生稻造成的产量损失结构进行了通径分析。根据虫量和产量损失的关系,结合现行稻谷价格,产量水平,防治费用等因素。确定允许为害损失率,同时建立了再生稻褐飞虱防治指标模型,按照防治指标模型,制定出不同产量水平的防治指标。 相似文献
75.
76.
Baumgartner, N. and Fondeville, J. C. 1989. Photocontrol of the hypocotyl hook opening of Sinapis alba seedlings. Involvement of phytochrome and a high irradiance response.
A statistical evaluation of the hypocotyl hook opening (hook opening index) was used for measurement of the hook angle in lots of etiolated Sinapis alba L. cv. Albatros seedlings. Studies of the kinetics for hook opening were carried out in continuous fluorescent white, blue and red light (6, 15 and 40 μmol m-2 s-1 ) with 2-day-old dark-grown seedlings. At the beginning of the irradiation period the photoresponse in red light was the opposite to that in blue (low photon fluences). Blue rapidly induced the hook opening (in less than 20 min), while red produced hook tightening (photon fluences up to 70 mmol m-2 ), which precedes the normal progressive hook opening. For low fluences, the data were consistent with the involvement of phytochrome and a specific blue light photoreceptor. A phytochrome effect was observed in the hook opening, dependent upon a high irradiance response (HIR). This HIR (like that for the inhibition of the hypocotyl elongation) was characterized by a wavelength response curve with maxima in the blue and far-red regions of the spectrum. 相似文献
A statistical evaluation of the hypocotyl hook opening (hook opening index) was used for measurement of the hook angle in lots of etiolated Sinapis alba L. cv. Albatros seedlings. Studies of the kinetics for hook opening were carried out in continuous fluorescent white, blue and red light (6, 15 and 40 μmol m
77.
Ecological compensation of the impacts of a road. Preliminary method for the A50 road link (Eindhoven-Oss, The Netherlands) 总被引:5,自引:0,他引:5
After years of efforts to avoid or reduce the impact of infrastructure projects on nature, the principle of ecological compensation has been incorporated in Dutch governmental policy. Ecological compensation aims to recover those ecological functions and natural values that still remain affected after maximum effort has been made to reduce the impact of the intervention (mitigation). The accepted aim of current policy is thus no-net-loss of area and quality by means of mitigative and compensatory measures. As part of the planning process for construction of a stretch of road in The Netherlands, viz., the A50 road link in the province of North Brabant, a Nature Compensation Plan (NCP) was required to be drawn up. This work has recently been completed by the Regional Directorate of Public Works and Water Management, the initiator of the intervention. The NCP, initially presented as a Draft Plan, was drawn up by the Regional Directorate using a preliminary method designed by the Centre of Environmental Science of Leiden University for deriving compensatory measures. After an opportunity for public comment, the Draft Plan was revised to form a Final NCP. This article describes, firstly, the preliminary method for deriving ecological compensatory measures. The method starts by quantifying the effects of habitat loss, habitat disturbance (by changes in noise emissions, in the water table and in outdoor recreational patterns), barrier action and fauna casualties. Following mitigation of impacts on nature, compensation for non-mitigable effects focuses successively on area size, derived from the impacts on breeding birds, and on area quality, derived from the habitat requirements of the vegetation and fauna groups affected by the road. Guidelines for identifying appropriate locations for compensation are also formulated. Secondly, the compensation method is applied to calculate the mitigative and compensatory measures for the A50 trajectory between Eindhoven and Oss. Thirdly, two comparisons are made: the Draft NCP is compared with the results of the preliminary method, and the Draft and the Final NCP are compared with one another in order to identify the role of the interest groups that played a major role in commenting on the Draft Plan. Finally, realization of the compensatory measures and development of the preliminary method itself are discussed. On the basis of the experience with the A50 case study, a more robust compensation method for road projects is to be developed. 相似文献
78.
日粮水平对鲇鱼日总代谢,特殊动力作用和活动代谢的影响 总被引:4,自引:0,他引:4
在25℃不同日粮水平(饥饿─4%体重/d)条件下,采用封闭式呼吸仪测定了31尾鲇鱼(体重72.9─133.3g)的日总代谢率,然后,将鱼限制在呼吸室中的限动笼内测定了其中20尾鲇鱼的静止日总代谢率,并计算出了鲇鱼的特殊动力作用(SDA)和活动代谢率。日总代谢率和活动代谢率都随日粮水平的升高呈“V”形变化,分别在约1%和2%体重/d的日粮水平时最低,SDA的能量支出占摄入能量的22.14%。 相似文献
79.
乳链菌肽的分离纯化和部分生物学性质 总被引:1,自引:0,他引:1
用乳酸链球菌SM526进行乳链菌肽的发酵生产,产量为40~50mg/l.经中空纤维超滤器超滤,非极性大孔吸附树脂XAD-2层析,CM-SephadexC-25层析和SephadexG-50层析纯化了该肽。SDS-PAGE表明达均一,RP-HPLC表明其纯度不低于95%。SDS-PAGE测其Mr约为3600,用IEF测其等电点为9.5.酸性条件下稳定且抗热;对胰蛋白酶、胃蛋白酶和木瓜蛋白酶不敏感,但对α-胰凝乳酶和蛋白酶K敏感。乳链菌肽对多种革兰氏阳性菌有强烈的抑制作用;以枯草杆菌和金黄色葡萄球菌为指示菌,其作用方式是杀菌。 相似文献
80.
Takeshi Nishimura Setsuko Yamamoto Takaaki Yamamoto Munekiyo Kaneko Youichi Hara 《Prostaglandins & other lipid mediators》1996,51(2):149-159
The antithrombotic effect of topical application of the 3-oxamethano-prostaglandin (PG) I1 analog, SM-10902 in the microcirculation and in vitro antiplatelet functions of its active form SM-10906 were estimated in comparison with PGI2 and PGE1. In rat platelets, SM-10906 evoked accumulation of intracellular cyclic adenosine 3′,5′-monophosphate, and exhibited antiaggregatory and disaggregatory activities, which were all enhanced by the phosphodiesterase inhibitor theophylline. Additionally, SM-10906 was shown to inhibit platelet adhesion to collagen in human platelet-rich plasma. PGI2 and PGE1 also showed in vitro antiplatelet effects in the order of PGI2 > SM-10906 ≥ PGE1. SM-10902 exhibited a dose-dependent antithrombotic effect in the guinea pig mesenteric arteriole by a topical application, and this activity might be exerted by the antiplatelet functions of SM-10906. Although SM-10906, PGI2 and PGE1 also showed the antithrombotic effects, SM-10902 was the most potent. In conclusion, the present studies indicate that an external topical preparation of SM-10902 may be useful for the therapy of peripheral circulatory insufficiency. 相似文献