摘要:

AbstractChanges in Fruiting Rhythm of Coprinus congregatus by Addition of Exogenous Mature Sporophores on the Surface of Cultures.Researches were performed over the regulating effect of mature sporophores on the fruiting rhythm ofCoprinus congregatusBull. ex Fr. Placing exogenous mature fruit‐bodies on the vegetative mycelium before the accomplishment of the first flush gives an abundant and perfectly synchronized fructification for this flush. But the fruiting rhythm is then disturbed: compared to control cultures, less sporophores are produced in the following flushes, and, in most cases, the cultures are finally characterized by fewer flushes than the controls. The nature of the substance(s) hypothetically produced by mature sporophores, which may regulate the production of other fruit‐bodies, and, correlatively, the fruiting rhythm, is as yet unkn

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1977.tb04036.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractPine pollen (Pinus mugo) grown in suspension cultures readily utilize exogenous carbohydrates for tube growth and starch synthesis: these processes are not influenced by β‐indolylacetic acid, gibberellic acid, kinetin and abscisic acid. It appears that the free sugars of the female gametophyte, namely sucrose, raffinose, and stachyose and their monosaccharide constituents, are the best substrates for growth and polysaccharide synthesis. The oligosaccharides are hydrolysed to their monosaccharide constituents before they are taken up. A preferential uptake of fructose is noted. Non‐metabolizable sugars are not taken up. The data presented establish that tube growth, except for the initial growth phase, can be determined by the availability of exogenous carbohydrates.Measurements of some of the key enzymes in carbohydrate metabolism show that the enzymes were present in the ungerminated pollen grain, and that the enzyme activity increased severalfold during tube growth. The increase in enzyme activity was prevented if inhibitors of protein synthesis were present in the me

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1977.tb04037.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractThe uptake and transport of Ca2+and HPO42−from roots ofLolium perenneL. was studied using variable N nutrition supplied to halves of a divided root system. Plants were grown for 4 weeks in solution containing 0.11 mMNO3−–N; then one‐half of the root system was supplied with either 4.0 mMNO3−–N or 0.28 mMNH4+–N while the other half of the root system remained in low‐N solution.Uptake and transport of Ca2+increased and uptake of HPO42−declined in root halves supplied with high NO3−–N for 16 h. After supply of high NO3−–N or NH4+–N to half the root system for 6 days, the roots supplied with high‐N exhibited significantly higher rates of uptake and percentage transport to shoots of both Ca2+and HPO42−–. However, in neither the 16‐h nor 6‐day treatment did Ca2+or HPO42−uptake of the root half supplied with low N differ significantly from the control (low N supplied to both halves of the root).Significantly higher N concentrations were found in low‐N supplied roots (compared to the control) as a result of internal translocation of N from high‐N supplied roots to low‐N supplied roots. Although N concentration in the low‐N supplied roots increased, uptake rates of Ca2+or HPO42−did not change implying that external N concentration may be the important factor which influences or governs N mediated uptake responses. This would further suggest that the site of uptake regulation for Ca2+and HPO42−exists on the outer plasma membrane which is in direct contact with the external solution.Transport of Ca2+and HPO42−to the shoot was generally increased in low‐N root halves after 6 days of high‐N supply to the other half of the root. This implies that plant growth demand may be a major factor in regulating rates of Ca2+and HPO42−transport from roots to the shoot. It also reinforces the hypothesis that uptake and transport of ions out of t

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1977.tb04038.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractOptimal extraction conditions, assay conditions, and levels of nit rate reductase activity (NRA) were determined for eight forage grass species adaptable to growing conditions in western North Dakota. Optimal pH for extraction of the enzyme nitrate reductase (NADH: nitrate oxidoreductase) for these species ranged from 7.0 to 9.5, whereas assay pH was 7.6 in all eight species. Substrate concentrations ranged from 1.0 to 10.0 mMfor maximum NRA with higher concentrations (100 mM) significantly inhibiting NRA. The enzyme was NADH2(0.1 to 0.2 mMfor maximum activity) specific. Enhancement of maximum activity with the addition of cysteine during extraction was species dependent; six species required high cysteine concentrations between 5 mMand 10 mMand one species required only a 2.5 mMconcentration. The degree of sulfhydryl protection offered by cysteine also varied. Comparisons were made betweenin vivoandin vitroassay methods. Ratios ofin vitrotoin vivoNRA ranged from 2.2. to 10.8. Use of bovine serum albumin as a protein stabilizer during extraction increased the measurable NRA in some species. Applications of nitrate reductase assay techniques to field work will be discussed.

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1977.tb04039.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractThe apices ofLupinus albusL. were analysed for cytokinin activity at three stages of development. Little cytokinin activity could be detected in the apices at the time of flowering. However, a considerable amount of activity was detected as the fruits developed. Separate analyses of seed and pod material indicated that there was a high level of cytokinin in both these parts of the fruit. After fractionation of the peaks of activity obtained from paper chromatograms on Sephadex LH‐20, four peaks of cytokinin activity were recorded. Two of these co‐eluted with zeatin and zeatin riboside. A third peak at an elution volume of 360–440 ml could be hydrolysed with β‐glucosidase to give activity at elution volumes corresponding to those of zeatin and zeatin riboside. This strongly suggested that both glucosylated zeatin and glucosylated zeatin riboside were present in the developing fruits of L. albus. The fourth peak at an elution volume of 160–280 ml did not disappear upon hydrolysis with β‐glucosidase, and it is possible that it represented a nucleot

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1977.tb04040.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractTransport of the cytokinin 6‐benzylaminopurine‐8‐14C in the root and shoot of intactCitrus aurantiumL. seedlings was studied by “replacing” the 0.5 cm root tip with the uptake solution. The cytokinin was transported basipetally in the root and was distributed in an acropetal direction in the stem and into the leaves. Kinetic analysis of the transport for periods of up to 96 h revealed a characteristic advancing front of the label along the axis of the seedling. The estimated velocity of transport of 6‐benzylamino‐purine‐8‐14C in various regions of the intact root was 2.6 to 5.1 mm/h.The transport of 6‐benzylaminopurine was predominantly in the transpiration stream, in stelar tissues of the root. Conditions of high transpiration favored enhanced transport to the shoot and an overall greater accumulation of the label. The total accumulation of 6‐benzylaminopurine in roots of intact seedlings after 48 h of transport was 354% of that in roots of shoot‐less seedlings. Root girdling and treatment of the root with KCN did not reduce the basipetal transport of the label in the root and into the shoot.Radiochromalogram scanning of root extracts and analysis of the ethanol insoluble‐NaOH soluble fraction revealed considerable metabolic changes in the translocated cytokinin. Only 51% of the radioactivity remained in the original 6‐benzylaminopurine peak after 24 h of incubation. Two other, unidentified, metabolites were detected.It is suggested that all the factors that affect the ascent of sap are involved in the long‐distance transport of cytokinins, and that the rate and mode of transport of cytokinins from the root system to the shoot may be a major factor in the expression of

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1977.tb04041.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractThe transport and distribution of IAA‐2‐14C, gibberellin A3‐3H, 6‐benzylaminopurine‐8‐14C and sucrose‐14C (U) were studied in whole seedlings ofCitrus aurantiumL. after “replacing” the root tip with the solution of radiochemicals. All four substances were transported basipetally in the root and were distributed to the stem and leaves. The pattern of distribution of the label from 6‐benzylaminopurine was similar to that of sucrose, while a considerably larger amount of gibberellin A3was transported to basal regions of the root, away from the tip, and into the shoot. Contrary to these three substances, the basipetal transport of IAA in the root was very low, and the majority of the label was retained in the terminal sections of the root.It is suggested that the different efficiencies at which various hormones move in the transpiration stream in the root may be an important factor in the attainment of a certain balance of ho

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1977.tb04042.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractA relatively simple and reproducible technique to analyse both longitudinal and transversal biochemical microgradients in roots has been presented. Although no statistically significant differences of acid phosphomonoestherase activity were found between upper and lower faces of geostimulated maize roots, an increase of activity was demonstrated in the two first mm of the horizontal roots in comparison with the vertical roots. These results were discussed in conection with the growth variation of these roots.

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1977.tb04043.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractAspergillus sydowi(Bain.&Start.) Thom&Church grew and sporulated best at 30°C. The best pH for growth and sporulation was 5.5. Light was stimulatory to sporulation but inhibitory to growth. Among the carbon sources employed, sucrose supported the best growth and sporulation. Nitrate, ammonium and asparagine were good nitrogen sources for growth and sporulation. During utilization of sucrose, the carbohydrates found in the mycelium included dulcitol, inositol, mannitol, arabinose, trehalose and galactose

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1977.tb04044.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractDuring growth in liquid culture medium, that contained single soluble or insoluble cellulosic carbon source,Aspergillus sydowi(Bain.&Start.) Thom&Church released cellulolytic enzymes into the medium. The enzymes were separated by gel filtration followed by ion exchange chromatography into three components, all of high molecular weight. One of the components (Ac) has the character of a C1cellulase enzyme. In the assay for hydrolysis of insoluble cellulose, the combined fractions, especially whenever the fraction under test contained the component Ac, released more glucose than when each component was employed alone.

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1977.tb04045.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY