摘要:

AbstractBleeding sap of sunflower seedlings (Helianthus annuus) which had been transferred to59Fe‐ or54Mn‐labelled nutrient solution 16 hours before decapitation, was fractionated by gelfiltration on Sephadex G‐15.In both the59Fe‐ and the54Mn‐labelled bleeding sap three fractions could be determined, containing the microelement together with amino acids and carbohydrates.According to the results of gelfiltration, the molecular weight of these compounds ranges b

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06460.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractThe importance of light to the induction of nitrate reductase activity in barley (Hordeum vulgareL.) was studied. Activity in etiolated leaves in darkness stayed at a low endogenous level even while large amounts of nitrate were actively accumulated. Light was required for any increase in activity, though the requirement may be satisfied to a limited extent before nitrate is available. Nitrate reductase activity was induced in the dark in green leaves which had not previously had nitrate but were supplied nitrate at the beginning of the dark period. If the nitrate then made available was sufficient, nitrate reductase activity increased until the effect of the previous light treatment was exhausted. Activity then decreased even though nitrate uptake continued. Upon returning the leaves to light, enzymatic activity increased again, as expected.Nitrate uptake was eliminated as an experimental variable by giving dark‐grown plants nitrate, then detaching the leaves for induction studies. Under these conditions light saturation occurred between 3600 and 7700 lux at exemplary periods of illumination. At intensities of 3600 lux and above, activity increased sharply after a 6‐hour lag period. As light intensity was decreased below 3600 lux the lag period became longer. Thus, when sufficient nitrate was available, the extent of induction of nitrate reductase activity was regulated by li

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06461.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractThe effects of CCC on the32P amounts absorbed by cotton seedlings were studied. CCC was applied to the seedlings either as spray or as addition to the nutrient solution in concentrations of 0, 25, 50, 100 and 200 mg/1.32P was added to the medium as KH232P O4in the concentration of 40 μCi/50 ml.During the experimental period, no morphological changes were observed. The total32P uptake was inhibited in CCC treated seedlings. The application of CCC, both as spray and as addition to the medium, led to an accumulation of32P in stem, but to a decrease in root. The leaves showed different responses to different methods of application; spraying increased, while an addition of CCC to the medium decerases the32P content in the leaves. It is concluded that CCC inhibits32P uptake, whereas it ac accelerates the32Ptranslocation from root to the aerial parts

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06462.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractVerticillium albo‐atrumgrew on lactose‐containing culture media only after a prolonged lag phase. The intracellular specific activity of β‐galactosidase [EC 3.2.1.23] increased 40–200 times during he lag phase. The β‐galactosidase was induced by lactose and to a lesser degree by galactose. The appearance of the enzyme in lactose cultures was decreased by cycloheximide. Glucose and other readily metabolized carbon sources were effective repressors of β‐galactosidase production. The production of β‐galactosidase therefore appeared under control by lactose induction and cata

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06463.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractThe results of synchronous registering of bioelectrical potentials upon some cell phases under definite environemental conditons can be used more universally in studies on the nature of bioelectrical appearances in living plant cells.Determinations were made on different functional dependence of the bioelectrical potential of the outside cell membrane, the bioelectrical potential of cytoplasm and the bioelectrical potential of vacuola under the same environmental conditions. Different properties of the cell structures manifest unequal characteristics in rhytmical fluctuation of bioelectrical potentials; unsynchronous and synchronous rhytmical fluetuations in the bioelectrical potential of cytoplasm and the outside cell membrane might occur. The amplitudes of the cytoplasm biometrical potential and the corresponding amplitude of biometrical potential in the outside cell membrane range up to 70 mV and 15 mV, respectively.

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06464.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractThe effect of white, blue, yellow, red and far‐red light on the quantitative synthesis of the primary and auxilliary photosynthetic pigments in cultured leaf primordia ofOsmunda cinnamomeaL. is reported. The P660form of the now classical photoreceptor pigment system, phytochrome, has been demonstrated to be active in chlorophyll synthesis in cultured cinnamon fern leaf primordia as shown by red/far‐red reversibility of chlorophyll synthesis. Also, it is apparent from the data presented that a blue absorbing pigment (P420) is responsible for the extensive accumulation of chlorophylls and carotenoids in these cultured lea

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06465.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractAddition of octanoic acid (2· 10‐3M) to the suspending medium (final pH 4.85) ofBoletus variegatusmycelium induced a marked leaking of UV absorbing substances from the cells. The material had an absorption maximum at 260 nm, a minimum at 240 nm, and the absorption ratios 250: 260 and 280:260 were 0.81 and 0.49.The material released immediately after addition of the acid consisted mainly of low molecular weight substances. These substances, listed according to decreasing rates of leaking, were identified as pentoses, pentosephosphates, nucleosides, and mono‐ and di‐nucleotides. Also, purine and pyrimidine bases were released at this early stage of treatment.After 90 minutes' treatment, an outflux of oligoribonucleotides was observed. The oligoribonucleotides did not occur as single substances, but were forming complexes with peptides. Minor amounts of ribonucleic acid were also leaking out from the cells. Deoxyribose containing substances were never observed in the filtrates.The compounds were subjected to enzymatic degradation after they had left the cells. This was shown by a marked increase with time of inorganic phosphorus, pentose/pentosephosphates, and nucleosides in the filtrate.The leaking of low molecular weight substances immediately after acid addition is correlated to seriously reduced growth. However, the growth was wholly restored after a three days' lag period. On the other hand, when considerable amounts of oligoribonucleotide peptides had been released from the cells, growth could not be re‐est

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06466.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractThe aim of this work was to determine the effect of DMSO on the uptake and translocation of potassium and phosphorus applied on corn and bean leaves. Radioactive isotopes42K and32P were used in most of the experiments. The results obtained reveal that DMSO (0.5% and above) increases the penetration of potassium applied as nitrate or chloride, but seems to have no effect on the penetration of32P when applied as different phosphates.

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06467.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractSilene secundiflorais a Mediterranean species restricted in range to the southern coasts of Spain and the Balearic Islands. Germination tests were made in incubators and on thermo‐gradient bars to evaluate changes in temperature‐responses at intervals after seed harvest. Results were compared to average temperatures occurring in the region and interpreted in relation to the climatic characteristics of the area.Germination of freshly harvested seed was restricted to a narrow temperature band between ca. 7 and 16°C. After‐ripening during the first four months resulted in a progressive widening of the temperature band favouring germination, but this remained below average summer temperatures. Exposure of imbibed seed to high temperatures (31°C) reduced the subsequent temperature maximum for germination by about 4°C, but did not induce a fully effective secondary dormancy. The results appeared to be well correlated with a situation in which germination normally occurs in September at the start of the winter growin

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06468.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractPlants of a pure line variety, G 24, ofCicer arietinumL. were grown in sand culture. After an initial dose of a complete nutrient solution, a nitrogen free nutrient solution was supplied to the sand at intervals and a standard rhizobial culture was added twice. The plants were treated with two concentrations of gibberellic acid (20 mg/I and 100 mg/I) through the rooting medium. At suitable intervals two pots from each treatment were sampled. Observations were made regarding the earliest initiation of nodulation, the number, weight and colour of nodules and the nitrogen content of different plant organs under various treatments.GA3treatments enhanced nodule initiation. While 20 mg/1 somewhat enhanced nodule number, weight and nitrogen content, 100 mg/I caused detrimental effects in the long run. Pod formation was delayed with GA3, the effect being much more pronounced with the higher concentration used. Pod and seed weights under 20 mg/1 GA3were almost comparable to the control, but 100 mg/I proved very deleterious.

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06469.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY