解剖学和形态学
麻醉学
听力与言语-语言病理学
行为科学
心脏和心血管系统
细胞和组织工程学
临床神经病学
危重症监护医学
牙科,口腔外科和医学
皮肤病学
急诊医学
内分泌学和新陈代谢
肠胃学和肝脏学
老人病学和老年医学
卫生保健科学和服务
血液学
免疫学
传染病
综合和补充性医学
医学伦理学
医学信息学
医学实验室技术
医学,全科和内科
医学,法律
医学,研究和试验
神经系统科学
护理
营养学和饮食学
产科医学和妇科医学
肿瘤学
眼科学
整形外科学
耳鼻喉科学
病理学
儿科学
周围血管疾病
药理学和药剂学
生理学
基本医疗保健
精神病学
公共、环境和职业卫生
放射学,核医学和医学成像
康复学
生殖生物学
呼吸系统
风湿病学
运动科学
外科学
毒理学
热带医学
泌尿学和肾脏学
病毒学
老年医学
健康政策和服务
心理学,临床
abstract::Isotope analysis of the biochemical fractions isolated quantitatively from young and mature leaves of Bryophyllum daigremontianum Berger have been carried out before and after a dark period of accumulation of organic acids. The mature leaf is enriched in (13)C compared to the young leaf. The δ(13)C values of the diffe...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00384896
更新日期:1977-01-01 00:00:00
abstract::Phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) and cinnamic acid 4-hydroxylase (CA4H, EC 1.14.13.11) undergo concomitant increases in activity after a 2 h lag following disc preparation and illumination. The increases in PAL and CA4H activity can be inhibited by actinomycin-D, cordycepin and cycloheximide. It is demons...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00387167
更新日期:1977-01-01 00:00:00
abstract::The retention of photosystems I and II and or RuDP carboxylase activity in chloroplasts isolated from the first leaves of Victory oat (Avena sativa L.) seedlings was followed as the chloroplasts senesced in darkness. Both photosystems (PS) I and II retained their full activity after 3 days at 1°C, while even after 7 d...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00387157
更新日期:1977-01-01 00:00:00
abstract::Tobacco leaves (Nicotiana tabacum var. Wisconsin 38) submitted to anaerobic conditions behave in a manner similar to that of maize, sugarcane, or sorghum leaves (C4-plants); more precisely, a lag time in O2 release is exhibited when the leaves are exposed to light after treatment in the dark under pure nitrogen. Altho...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00387973
更新日期:1977-01-01 00:00:00
abstract::Incorporation of [(14)C]uridine into ribosomal RNA and ribosomal RNA precursor fractions was studied in isolated wheat embryos and in embryos remaining within the intact grains during germination. In isolated embryos, radioactive 25S and 18S as well as 31S RNA species appeared already within the first 3 h of germinati...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00384191
更新日期:1977-01-01 00:00:00
abstract::The activities of nitrate reductase (EC1.6.6.1), nitrite reductase (EC 1.6.6.4), glutamine synthetase (EC6.3.1.2), glutamate synthase (EC1.4.7.1) and NAD(P)H-dependent glutamate dehydrogenase (EC 1.4.1.3) were investigated in mesophyll and bundle sheath cells of maize leaves (Zea mays L.). Whereas nitrate and nitrite ...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00384971
更新日期:1977-01-01 00:00:00
abstract::The response of net photosynthesis and apparent light respiration to changes in [O2], light intensity, and drought stress was determined by analysis of net photosynthetic CO2 response curves. Low [O2] treatment resulted in a large reduction in the rate of photorespiratory CO2 evolution. Lightintensity levels influence...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00384961
更新日期:1977-01-01 00:00:00
abstract::No phytochrome can be detected spectrophotometrically in soybean (Glycine max (L.) Merr. cv. Mandarin) cell suspensions grown in darkness. White light from a tungsten filament lamp and a band of far-red light have been found to induce the appearance of phytochrome in them. Red light failed to bring about phytochrome i...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00390095
更新日期:1977-01-01 00:00:00
abstract::The vegetative prothalli (1-3 weeks old) of Anemia were incubated for 24 h in [(14)C]adenine. The RNA was phenol extracted from whole cells and the poly (A) sequences were isolated by nuclease digestion followed by poly (U)-sepharose chromatography. About 2-3% of the total radioactivity was retained on the column. The...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00390085
更新日期:1977-01-01 00:00:00
abstract::The cell-wall formation in the egg of Pelvetia fastigiata (J.G. Agardh) DeToni (Fucaceae) was studied with freeze-fracture. 1. The wall is lamellated with microfibrils approximately parallel in each lamella. The average orientation of microfibrils turns about 35° in each subsequent lamella. This slow turn gives rise t...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00386007
更新日期:1976-01-01 00:00:00
abstract::Solutions of organic substances show differing influences on the direction of phloem transport of (14)C-labeled assimilates in predarkened maize leaf strips, when externally applied to one end of the strip. One group of substances "pushes" the assimilates away from the site of application. Examples of this group are 7...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00399726
更新日期:1976-01-01 00:00:00
abstract::A re-examination has been made of the supposed regulation by the axis of cotyledonary isocitrate lyase (EC 4.1.3.1) activity in Cucumis sativas L. and Cucurbita maxima Duch. and greening in cucumis. When precautions are taken to ensure that isolated cotyledons and cotyledons attached to the axis have equal access to o...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00388904
更新日期:1976-01-01 00:00:00
abstract::Intact chloroplasts capable of high rates of CO2 assimilation completely oxidized 3-phosphoglycerate and dihydroxyacetone phosphate to glycolate when CO2 concentrations were low. Bicarbonate was converted first into products of the Calvin cycle and then into glycolate. Under high oxygen and at high pH values CO2 fixat...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00388894
更新日期:1976-01-01 00:00:00
abstract::The role of microtubules and ions in cell shaping was investigated in differentiating guard cells of Allium using light and electron microscopy and cytochemistry. Microtubules appear soon after cytokinesis in a discrete zone close to the plasmalemma adjacent to the common wall between guard cells. The microtubules fan...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00390333
更新日期:1976-01-01 00:00:00
abstract::The cytokinins present in the spring sap of Acer pseudoplatanus L. were investigated. Ribosyl-trans-zeatin, trans-zeatin and dihydrozeatin were isolated and identified by combined gas chromatography-mass spectrometry (GC-MS). A number of other cytokinin active fractions were observed. One of these was less polar than ...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00390323
更新日期:1976-01-01 00:00:00
abstract::Preparations of rapidly labelled RNA are usually heavily contaminated by rapidly labelled low molecular weight components. This contaminating fraction mainly contains nucleoside triphosphates, as previously reported, but also nucleoside tetra, penta and hexaphosphates. These highly phosphorylated nucleosides are, acco...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00385426
更新日期:1976-01-01 00:00:00
abstract::2-(Chloroethyl)phosphonic acid (CEPA) inhibited the rise in tannin production and phenylalanine ammonia-lyase EC 4.1.1.5 (PAL) activity shown by Acer cells in media containing 9.0×10(-7) M 2,4-D for a period of 2-3 days after its addtion. ...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00385416
更新日期:1976-01-01 00:00:00
abstract::The pistil of tobacco (Nicotiana tabacum L. cv. Wisconsin 38) is comprised of two fused carpels. The stigma is bilobed, papillose, and at maturity is covered with a sticky exudate. The style is solid. Both stigma and style are made up of four tissue elements-epidermis, cortex, vascular, and transmitting tissue. Transm...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00389993
更新日期:1976-01-01 00:00:00
abstract::CO2 exchange, (14)CO2 fixation and (14)C-labelled photosynthetic products of differently pigmented Anacystis nidulans (strain L 1402-1) were studied during the induction period at +30°C. The algae were grown at +35° C in an atmosphere of 0.04 vol.-% CO2 and measured under the same low CO2 concentrations. Changing the ...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00389983
更新日期:1976-01-01 00:00:00
abstract::Freshly isolated protoplasts or separated cells prepared from leaves of Nicotiana tabacum L. cvs. Xanthincor Turkish Samsun exhibit substantially greater incorporation of [(3)H] leucine and [(3)H] uridine into protoplast protein and RNA, respectively, when dilute rather than concentrated suspensions are incubated. Thi...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00387350
更新日期:1976-01-01 00:00:00
abstract::Mitochondria isolated from greening etiolated laminae of Avena sativa L. show changes in the permeability of their inner membranes during chloroplast development similar to those described earlier for plastids. Oxalo-acetate, succinate and α-keto-glutarate permeate most readily inner membranes of mitochondria isolated...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00387340
更新日期:1976-01-01 00:00:00
abstract::When cambial tissues are removed from tree stems of Eucalyptus regnans F. Muell. and incubated in vitro with [(14)C]glucose, [(14)C]galactose and [(14)C]fructose in the presence of sufficient PVP (polyvinylpyrrolidone) radioactive sucrose, members of the raffinose family and related sugars are synthesized. These resul...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00387843
更新日期:1976-01-01 00:00:00
abstract::Transamination between γ-aminobutyrate and α-ketoglutarate provides a pathway for the utilization of γ-aminobutyrate in fruit-bodies of Agaricus bisporus Lge. This reaction leads to the formation of succinic semialdehyde, a metabolic intermediate in the metabolism of γ-aminobutyrate to succinate in the cell. γ-aminobu...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00387833
更新日期:1976-01-01 00:00:00
abstract::In leaves of S. nigra, fragmentation of the rachis follows the autumnal abscission of leaflets and the high levels of ethylene produced by the senescing blades. Fragmentation is accompanied by cell growth and ultrastructural changes in a zone of cells precisely differentiated at the separation zone. Studies with expla...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00384421
更新日期:1976-01-01 00:00:00
abstract::Acid ribonuclease from cotyledons of Pisum sativum is very stable, with a temperature optimum of 65° C. It has a molecular weight of 17,500 and there is evidence that a fragment, with a molecular weight of 3,100, retains enzyme activity. Acid ribonuclease from the cotyledons of five-day old seedlings may be fractionat...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00384411
更新日期:1976-01-01 00:00:00
abstract::Isoelectric focusing of the membrane polypeptides derived from castor bean (Ricinus communis L.) endosperm glyoxysomes and endoplasmic reticulum reveals a close similarity in the composition of these membranes, consistent with a developmental relationship between the organelles. ...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00390852
更新日期:1976-01-01 00:00:00
abstract::Protoplasts from cultured cells of soybean (Glycine max L.) and from sweet clover (Melilotus officinalis L.) mesophyll cells were fused with polyethylene glycol and subsequently cultured for six days. The resulting fusion products as well as unfused protoplasts of each parental species regenerated cell walls and divid...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00390842
更新日期:1976-01-01 00:00:00
abstract::A delay of 20 to 30 min precedes a rapid increase in the production of ethylene when segments are excised from the petioles of tomato plants. Measurements made during this early phase may be better estimates of production by petioles on the intact plant than those made at later times. ...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00398271
更新日期:1976-01-01 00:00:00
abstract::The denaturation of Euglena gracilis in aggressive acids has been investigated by means of the chlorophyll oxidation. A comparative study in different halogen acetic acids revealed that the reaction kinetics are determined by a reaction between the acid anion and the outer membrane. The denaturation of cell membranes ...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00398261
更新日期:1976-01-01 00:00:00
abstract::The occurrence of heterotrophic nitrification in nitrogen-starved cells of Ankistrodesmus braunii was confirmed. The levels of nitrate and nitrite were measured over a period of four weeks. The validity of quantitative determinations in the presence of highly active nitrate and nitrite reductases is discussed. Whereas...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00390025
更新日期:1976-01-01 00:00:00
abstract::Ceratonia siliqua L. exhibited a sigmoid growth pattern with each stage being controlled by specific substances. At least three auxin-like substances were involved during fruit morphogenesis with the main one being at indole-acetic acid Rf. Auxin-like substances were present at highest level during stage II, when frui...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00390015
更新日期:1976-01-01 00:00:00
abstract::Articulated anastomosing laticifers were identified at both light and electron microscopic levels in the stamens of Papaver somniferum L. They were observed associated with the phloem forming a continuous system from the filament into the anther of the stamen. Laticifers, which were comparable in structure to laticife...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00390918
更新日期:1976-01-01 00:00:00
abstract::C2H4 production of the embryonic axes and cotyledons excised from dormant and non-dormant cocklebur (Xanthium pennsylvanicum Wallr.) seeds was examined in relation to ambient O2 tensions. There were two kinds of C2H4-producing systems, quasi-anaerobic and aerobic, in both organs. Regardless of the organ, the former ac...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00390908
更新日期:1976-01-01 00:00:00
abstract::The rate of glycolate excretion by Coccochloris peniocystis Kütz. cells incubated under conditions of low bicarbonate concentration and high light intensity was linear for only the initial 15 min of incubation and no additional glycolate accumulated in the medium after 20 min. Excretion was maximal in cells grown on 5...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00393232
更新日期:1976-01-01 00:00:00
abstract::Ribulose diphosphate (RuDP) and (PEP) phosphoenolpyruvate carboxylase enzyme activities were studied in young, mature, and senescent Portulaca oleracea leaves. While the absolute amount of both the C3 (RuDP) and C4 (PEP) carboxylase is less in senescent leaves than in mature leaves, RuDP carboxylase activity is reduce...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00390316
更新日期:1976-01-01 00:00:00
abstract::The excretion of glycolate by illuminated Chlorella vulgaris cells at low CO2 tension can be stimulated about tenfold by substituting O2 for air, or by addition of cyanide, hydroxylamine, hydrazine or semicarbazide to the cells in air. For each reagent there is a concentration range giving a maximum effect. It is prop...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00397182
更新日期:1976-01-01 00:00:00
abstract::Crude extracts of dark-kept resting cells of a chlorophyll-free, carotenoid-containing mutant of Chlorella vulgaris Beijerinck (211-11h/20) were found to convert 14.44±0.77 nmol PEP per min and mg protein into pyruvate by the action of pyruvate kinase (=PK; EC 2.7.1.40). When such cells were exposed to blue light (λ<5...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00397172
更新日期:1976-01-01 00:00:00
abstract::Only 11% of the total peroxidase activity in a root tip homogenate of Zea mays (L.) was sedimentable. The majority of sedimentable activity was bound to membrane fractions with which acid hydrolases were also associated.Peroxidase activity was released from a cell wall fraction exhaustively washed using homogenization...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00388056
更新日期:1975-01-01 00:00:00
abstract::Vomifoliol, a compound related to abscisic acid (ABA) but lacking the 2,4-pentadiene sidechain and so far found in four different plant families, caused as much stomatal closure in epidermal strips of Eichhornia crassipes (Mart.) Solms as ABA at identical concentrations. It appears worthwhile to investigate whether vo...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00385281
更新日期:1975-01-01 00:00:00
abstract::Phosphate absorption by segments excised from hypocotyls of Phaseolus aureus Roxb. was inhibited by either continuous or short-term illumination with red light. Maximal inhibition was observed at pH 6.5. Illumination with 800 erg cm(-2) s(-1) of red light for 5 min was sufficient to obtain maximal inhibition. The effe...
journal_title:Planta
pub_type: 杂志文章
doi:10.1007/BF00385271
更新日期:1975-01-01 00:00:00