摘要:

AbstractEarlier work has shown that protochlorophyll(ide) holochrome is associated with the prolamellar body membranes in etioplasts of barley (Hordeum vulgareL.), and that this pigment‐protein complex can be extracted in a stable, photoactive form by the use of saponin. For future work it would be advantageous if saponin, a detergent mixture, could be replaced by a single, well‐characterized substance. The spectral characteristics of holochrome extracted with 10 ionic and nonionic detergents were compared to those of the holochrome extracted with saponin. Mulgofen BC‐840 and digitonin extracted significant amounts of photoactive protochlorophyll(ide) holochrome, but this activity was highly labile, and no adequate substitute for saponin was found. Thus the stabilizing and solubilizing function of saponin is not simply related to the general properties of deter

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb02559.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractGrowth responses of hypocotyls ofBrassica oleraceaL. var.capitatacaused by diurnal irradiation of various duration (0.5 h/d up to continuous irradiation) and various irradiance (0.3–1.5 W m−2) with red and far‐red light from sources characterized below can be described by the equation:(W= relative effect,I= irradiance,t1= irradiation time per day,Ws= constant dependent on material and wavelength, α,Bandts, = constants dependent on wavelength.)On the basis of that equation a possible connection between longtime and short‐time irradiation responses is d

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb02560.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractConcentration‐dependence and other characteristics of uptake of3H‐labeledl‐lysine,l‐methionine andl‐proline by excised roots of barley (Hordeum vulgareL.) were studied. Use of relatively short uptake and wash periods and low solute concentrations ensured good estimates of influx across the plasmalemma.Uptake in the range of 10−7M– 6.3 × 10−3Mcan be precisely represented by four or five phases of single, multiphasic mechanisms. The mechanisms appear to be relatively specific as judged from the competition by unlabeled analogues. Structural requirements for interaction of a compound with the uptake site for methionine are given, as are the effects of analogues on the phase pattern for this amino acid. There is no indication of separate uptake and transition sites for methionine or lysine.i.e.phase transitions seem in this case to be caused by binding of molecule(s) to the uptake site.Uptake, but not phase patterns, was highly pH‐dependent. The optima were pH 5 for lysine, pH 3–5 (a broad peak) for methionine and about pH 5.5 for proline. Uptake of the three amino acids was strongly inhibited by 2,4‐dinitrophenol. sulfhydryl rea

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb02561.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe extent and manner of ethylene involvement in germination of lettuce (Lactuca SativaL. cv. Mesa 659) seed at a moderate temperature (20°C) were investigated. Inhibition of germination at low pressure of 150 mmHg in an oxygen flow‐through system was alleviated to a marked extent by ethylene. Carbon dioxide was ineffective by itself but caused further alleviation of inhibition in presence of ethylene and oxygen. Other seed treatments which partially alleviated the inhibition caused by low pressure included soaking in 10μMof fusicoccin and a prior treatment with acetone. Of the two ethylene adsorbents used, Purafil was more effective in inhibiting germination in a closed container. Although the ethylene biosynthesis inhibitor, 8‐hydroxyquinoline (1.0 mM). showed no effect on ethylene production, it markedly inhibited germination and the effect was partially reversed by ethylene and GA3. An ethoxy analog of rhizobitoxine, on the other hand, had little or no effect on germination but strongly inhibited the ethylene production. Although no causal relation of ethylene to germination was established, the evidence presented here implicates ethylene, together with other gases, in the regulation of germin

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb02562.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe reversibly photochromic pigment, phycochrome c, was extracted from the blue‐green algaNostoc muscorumstrain A. Action spectra were determined forin vitroconversions of the pigment from the short wavelength to the long wavelength form and vice versa. The action peak for the absorbance decrease at 650 nm is at 630 nm. During this decrease there is only a slight increase of the absorbance in the green region. Green and yellow light (maximum efficiency at 580 nm) completely restores absorbance at 650 nm. The observations are explained by the existence of three spectrally different forms of phycochrome c: Pc630and Pc650which equilibrate in darkness and Pc580which is reversibly photoconvertible to Pc630. We have also measured the absorbance changes brought about by saturating irradiations with light of various wavelengths (“photostationary state spectrum”). Extreme photostationary states were obtained with about 650 nm and 500 nm

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb02563.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractNuclei were isolated from protoplasts obtained fromParthenocissus tricuspidataCrown Gall callus tissues. The effect of various isolation procedures, detergent or ultrasonication, on yield and quality of nuclei was studied. A standard procedure, based on the use of 5 × 10−3% Triton × 100 — 6% PVP — 20% glycerol, may be carried out in 30 min and gives 80 to 90% yield of nuclei in which RNA polymerase activity is r

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb02564.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractCut seedlings of wheat plants(Triticum aestivumL. cv. Starke II Weibull) between 6 and 7 days old were water stressed in darkness by exposing them to air of 35% relative humidity 2.5 to 20 h. This treatment resulted in a water potential of ‐11 bars in the leaves after 20 h. The leaves were then rewatered and irradiated. The chlorophyll formation that took place in fully turgid leaves during the greening was markedly decreased in the case of the water‐stress pretreatmet. and especially the lag phase was prolonged. The longer the stress pretreatment the more evident was the subsequent effect on chlorophyll formation. However, no linear relationship was found between the amount of stress and the chlorophyll content. Protochlorophyllide regeneration from endogenously formed δ‐aminolevulinic acid was markedly decreased even after the shortest water‐stress period. However, protochlorophyllide accumulation from exogenously supplied δ‐aminolevulinic acid was only slightly decreased following the water‐stress pretreatment. Further more, the ratio of protochlorophyllide650to protochlorophyllide628was slightly reduced by the same conditions.During the stress period both abscisic acid and proline were accumulated in the leaves. The content of abscisic acid increased up to six times the normal level during water stress lasting for 20 h. The increase of proline was about three‐fold for similar treatment. After rewatering the leaves the levels of both abscisic acid and proline rapidly declined and reached. 10 h later, the levels found in unstressed seedlings.The increase in abscisic acid during water stress associated with impaired chlorophyll metabolism suggested that the after‐effect of water stress might be linked to chlorophyll metabolism through abscisic acid or some of its metabolites. The changes in proline content open the possibility that this substance could function as a reserve substance for the formation of chlorophyll after the discon tinuat

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb02565.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractPotassium has been found to enhance greatly the expansion response of cucumber cotyledons to cytokinins. A reduction of the response to kinetin is obtained with increasing age of the cotyledons. The lesser response is associated with lower levels of potassium remaining in the cotyledon. A high level of KCI in the incubation medium offsets the lower potassium content of the tissue and enables a much larger response to the cytokinins. At 40 mMKCI the response to kinetin is 4.2 times greater than in the absence of KCI. Calcium increases the effect of potassium on the response to kinetin. When incubated in 40 mMKCI and 10 mMCaCI2with 10 mg/I 6‐benzylamino‐purine, the final weight of the cotyledons is 6.8 times the initial weight after just 4 days. This KCI‐CaCI2combination is also found to promote chlorophyll synthesis in the usual cucumber cotyledon bio

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb02566.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractRoot growth respiration ofSenecio aquaticusHill (flood‐tolerant) andSenecio jacobaeaL. (flood‐sensitive) was calculated, assuming different P: O ratios. The growth respiration values were calculated on the basis of the chemical composition of root and shoot dry matter, in combination with published data on the energy costs of biosynthetic and transport processes. The comparison between calculated and experimental values suggests a relatively low efficiency of ATP utilization in the roots of the flood‐tolerant species.Root growth respiration ofS. congestus(R.Br.)DC., which is also flood‐tolerant, andPlantago lanceolataL. were also determined. The data showed that not all the flood‐tolerant species investigated had high root growth respiration values.An “overflow model’ is proposed to explain observed differences in root growth respiration be

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb02567.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractPollen from chasmogamous flowers ofSalpiglossis sinuataL. could not be induced to germinatein vitrounless stigmatal extract was applied to the culture medium. The substance that induces pollen germination in the stigmatal extract is water‐soluble and heat‐stable. Crosses could not be achieved between chasmogamous and cleistogamous flowers because of structural incompatibility. Pollinated pistils of chasmogamous flowers release a large amount of ethylene. The burst of ethylene release is due to an interaction between pollen tubes and stylar tissue and is directly proportional to the quantity of pollen placed on the stigma. Cleistogamous flower buds also produce a burst of ethylene at the time of pollination within the closed flower. The ethylene release may be a cause of reduced corolla development associated with cleistogamous flow

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb02568.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY