摘要:

AbstractIn submerged culture the mycelium ofGeotrichum candidumbreaks into fragments (arthrospores) which are either cylindrical or ellipsoidal in shape; the proportion of each spore type depends upon the glucose concentration in the medium. Above 0.2% glucose the ellipsoidal type prevails, whereas the cylindrical type is more abundant at lower glucose concentrations. The cylindrical spores and the mycelium have a very similar macromolecular composition, but the ellipsoidal spores have less RNA and protein and more carbohydrate than the mycelium.

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb04095.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe contents of GAs and growth inhibitors were investigated in the dwarf (cv. Masterpiece) and tall (cv. Kentucky Wonder) varieties of bean (Phaseolus vulgarisL.). The comparison of active substances was carried out by parallel extraction and fractionation from leaves of the two varieties followed by paper chromatography, thin layer chromatography (TLC) and bioassay, using lettuce hypocotyl growth test. Five GA‐like activities and six growth‐inhabiting activities, in which xanthoxin. ABA and bound ABA might be included, were detected in both dwarf and tall varieties. The levels of all of these GAs and inhibitors were almost identical between the two varieties. In both varieties GA3treatment caused two inhibitory activities to decrease. The expression of dwarfism in the vegetative growth stages of beans may have to be discussed also on the basis of another factor than that of the levels of endogenous GA inhibit

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb04096.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractImmature green peas were harvested from plants grown in water culture on Johnson's nutrient solution with radioactive chloride. Twenty five g of lyophilized peas were extracted with butanol, the extract chromatographed, first on Sephadex LH 20 and then on silica gel. The radioactive hormone was followed by scintillation counting without the use of any scintillant. The radioactive fractions were taken up in a few μl of chloroform and injected into a gas chromatograph interfaced with a mass spectrometer. Derivatization was not necessary. The electron impact mass spectrum showed the typical peaks of a chloroindolyl‐3‐acetic acid methyl ester: the molecular ion cluster atm/e223, 225 and the characteristic indole fragment ions atm/e164, 166 (M‐COOCH3)+. The chlorine atom was assigned to the 4 position of the indole ring after thin layer chromatography of radioactive extract and standards of four different chlorinated indolyl‐3‐acetic acid met

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb04097.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractIn order to investigate the possibility that cytokinins control transpiration indirectly through affecting leaf senescence, a direct comparison was made of the effect of different cytokinins on transpiration and senescence of oat leaves (Avena sativaL. cv. Forward). Senescence was assessed by measuring chlorophyll loss. The synthetic cytokinins N6benzyladenine (BA) and kinetin delayed senescence and increased transpiration of oat leaves to a greater extent than did the naturally occurring compounds zeatin, Nb‐Δ2isopentenyladenine (i6Ade) and 6‐ø‐hydroxybenzyladenosine (hyd‐BA riboside).During the early stages of the transpiration experiment zeatin showed similar or greater activity than BA. This period was longest when freshly excised leaves were used, was reduced when leaves were used after incubation in distilled water in the dark for 20 h and was eliminated by incubation in cytokinin solution in the dark. After this period the activity of zeatin declined relative to BA. The effect of cytokinins in increasing transpiration occurred only in the light; no effect was observed in the dark.BA showed higher activity than zeatin in senescence tests but both cytokinins were less effective as the tests progressed, this decrease in activity being more rapid when older leaves were used.The results are discussed in relation to the mechanisms by which endogenous cytokinins might control sensecence and transpiration in oat leaves and to the value of the oat leaf senscence and transpiration bioassays as tests for cytokinin activity of plant

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb04098.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe first sign of adventitious root formation in the petiole of the primary leaves ofPhaseolus vulgarisafter treatment with IAA was the dedifferentiation of mature parenchyma cells next to strands of sieve elements and companion cells. Colchicine strongly inhibited this dedifferentiation. Treatment with colchicine 3 days after treatment with IAA, caused the groups of meristematic cells formed to grow by cell enlargement only. Groups of more than about 30 meristematic cells changed into recognizable root primordia during this growth. Groups with a smaller number of meristematic cells extended also in size but did not form a recognizable root primordium.

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb04099.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe transpiration rate of oat plants, 6 days old, has been investigated. Dependent on the irradiance level of the white light used in the experiments, the transpiration rate oscillated with different period times. In darkness or at low irradiances the period was about 100–110 min. At higher irradiances the period was about 40 min. At intermediate irradiances autocorrelation analysis was used to find the period content of the transpiration rate. It was concluded that two oscillatory systems were present in the plants, characterized by their different periods.When plants cultivated in a light/dark cycle were used, the transpiration oscillations were influenced by a circadian rhythm. Oscillations in darkness were then most pronounced in the mornings. Plants cultivated in continuous light did not show such a circadian rhythm, but the oscillations died out after about 20 h.Kinetin induced transpiration oscillations in darkness and made them sustain for a longer tim

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb04100.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractStudies were conducted to determine the fate of14C‐maleic hydrazide injected into the stem xylem of 1‐year‐old silver maple (Acer saccharinumL.) and American sycamore (Platanus occidentalisL.) seedlings. Maleic hydrazide was found to translocate to all parts of the plant within 1 day after treatment. The autoradiographs indicated that the radioactivity was accumulated in meristematic regions of the leaves. A significant amount (over 15% of the applied14C) was exuded out of the roots into the nutrient solution after 30 days. The14C in the nutrient solution was in the form of unchanged maleic hydrazide, whereas in plant tissue a metabolite possibly a conjugate with sugar was formed. With the passage of time, the amount of metabolite seemed to increase in proportion to that of maleic hydrazide. Approximately 30% of the applied14C was unextractable with methanol after 30

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb04101.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractExogenously supplied nitrogenous bases in combination with IAA + sucrose hastened the formation of roots on hypocotyl cuttings ofPhaseolus mungoL. cv. G31. While purine and pyrimidine bases had little effect when used alone, together with IAA or sucrose they increased the number of roots and the effect was even more pronounced in combination with (IAA + sucrose). By contrast, guanine inhibited rooting completely in higher concentrations even in combination with (IAA + sucrose), and cuttings died within 48–72

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb04102.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractExtracts from hypocotyls of germinating peanuts (Arachis hypogaeaL.) stimulated the formation of thymidine monophosphate from thymidine and adenosine triphosphate in the presence of magnesium ions. Such extracts were incapable of incorporating isotopic phosphorus from gamma‐labelled adenosine triphosphate into thymidine during the synthesis of thymidine monophosphate but were competent in transferring phosphorus from alpha‐labelled adenosine triphosphate to thymidine. The apparent thymidine kinase activity thus appeared to result from the combined activities of an adenosine triphosphatase (adenosine triphosphate pyrophosphohydrolase, E. C. 3.6.1.3) and a nucleoside phosphotransferase (E. C. 2.7.1.77). The latter two enzymes could be largely separated by using DEAE‐Sephadex chromatog

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb04103.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractImbibition of celery (Apium graveolensL.) seeds at 32°C for up to 96 h lowered the upper temperature limit for germination. If this high temperature treatment was given in the light, these seeds germinated slightly earlier than those treated in the dark although the final percentage germination was similar for both treatments. The inhibitory effect of the high temperature treatment was completely removed by allowing the seeds to imbibe in a mixture of the gibberellins A4and A7(GA4/7) and partially removed by the cytokinin N6‐benzylaminopurine (BA). GA4/7was less effective when added before rather than after the high temperature treatment, whereas the opposite was true of BA. At constant temperatures more GA4/7was required to promote germination as the temperature was raised but addition of BA reduced the concentration of GA4/7required. A model is proposed for the control of celery seed germination by light and temperature through the action of endogenous cytokinins and gibberelli

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1978.tb04104.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY