摘要:

AbstractHypocotyl tissue fromPinus gerardianawas established in culture on White's basal medium supplemented with 2 % sucrose, 10% (v/v) coconut milk, 500 mg/l casein hydrolysate and 1 mg/1 2,4‐dichlorophenoxyacetic acid (2,4‐D).Various organic and inorganic nutrients were studied in order to determine the specific nutritional requirements of the tissuein vitro. Sucrose, glucose and maltose were equally effective as fixed carbon sources. The inorganic nutrient combination of White's medium was found to be better than that of Murashige and Skoog's medium. White's modified basal medium supplemented with coconut milk, casein hydrolysate and 2,4‐D was the most successful nutrient combination. Glutamine was as effective as casein hydrolysate in promoting growth of the t

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03121.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractSince the existence of root promoting substances that consist of a complex between auxin and another molecule has been suggested, we have examined the role of auxin conversion products in root regeneration byPinus lambertianaembryo cuttings. Auxin conversion products were detected using radioactive forms of the auxins IAA (indoIe‐3‐acetic acid), NAA (a‐napthaleneacetic acid) and 2,4‐D (2,4‐dichlorophenoxyacetic acid). 10−7MNAA was more effective than 10−6MIAA at promoting rooting, yet it formed conversion products much less rapidly. Also continuous exposure to IAA was necessary for optimum root formation. Based on these and other findings, we conclude that free auxin, and not the conversion products we detected, is essential to root meris

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03122.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractFrom autoradiographical experiments on water‐imbibing pea (Pisum sativum) or Phaseolus mungo cotyledons supplied with glucose‐14C or iodoacetic acid‐14C, it was shown that the compounds did not penetrate into the innermost part of the cotyledons but remained in the peripheral region during the early germination period. Changes in the rates of incorporation of14C into alcohol from glucose‐14C were examined during the early period of germination, and it was concluded that glucose supplied exo‐genously was actively metabolized in the peripheral region. Endogenous alcohol formation was supposed to occur mainly in the peripheral region in the early phases of germination. On the basis of these results, the heterogeneity of the distribution of physiological activities in the cotyledon is

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03123.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe protochlorophyllide ester isolated from dark grown barley leaves was shown to contain geranylgeraniol as esterifying alcohol. No phytylester was found. The qualitative analyses were performed with combined gas chromatography‐mass spec‐trometry. Chromatographic separation and spectrofluorometric determination of the protochlorophyll and chlorophyll pigments before and after irradiation of the dark grown leaves with light flashes at 2°C showed that part of the protochlorophyllide ester was photoconverted to chlorophy

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03124.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractSeedlings of Douglas‐fir from seed of a number of mesic and xeric origins were grown in growth chambers and a nursery to various ages up to 16 weeks. Measurements were made to determine the effect of seedling age, growth chamber and nursery pre‐conditioning, and seed source on transpiration rates under closely controlled laboratory conditions. Additional experiments were conducted on seedlings of two contrasting ecotypes to determine the effect of different pre‐conditioning combinations of plant and soil water potential on seedling transpiration rates. Results show that well‐watered seedlings of two mesic ecotypes show no decline in transpiration rates per unit leaf area up to 16 weeks of age while corresponding seedlings of three exeric ecotypes do decline. The growth chamber pre‐conditioning results in lower seedling transpiration rates and more decline in seedling transpiration rates with increasing plant water stress than for nursery pre‐conditioning. In a similar way, the xeric ecotype seedlings have more decline in transpiration rates with increasing plant water stress than do the mesic ecotype seedlings. Soil water potential influences transpiration rates through pre‐conditioning effects. Seedlings which have experienced prior soil moisture stress decrease transpiration more in response to low plant water potentials than do plants which have experienced no soil moisture stress. These behavioral characteristics illustrate adaptive means by which seedlings conserve water through the interaction of genetic and preconditioni

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03125.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractStacking of chloroplast lamellae, isolated from normal and carotenoid mutant chloroplasts of maize (Zea maysL.), was determined after a high‐salt treatment.Stacking of isolated lamellae under favourable ionic conditions was almost identical with that occurring in intact chloroplasts; thus, differences in granum content could be attributed to the architectural properties of lamellae.Gaussian analyses, performed on the red band of room temperature absorption spectra, have shown that chloroplasts with lamellae of high stacking capacity contain relatively more Chla662than chloroplasts containing lamellae of low stacking capacity. The presence of Chla705–708was characteristic of preparations containing considerable amounts of stroma lamel

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03126.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe chloroplasts from wheat leaves developed under intermittent illumination (1 ms light + 12 min dark) were able to photoreduce DPIP with DPC as electron donor but unable to photoreduce DPIP with water as electron donor. On exposure of these leaves to continuous light, the Hill activity with water as electron donor was rapidly induced. The photoactivation was sensitive to the treatment with DCMU prior to exposure to continuous light. The action spectrum for the photoactivation showed a sharp band at 680 nm with a distinct shoulder at 650 nm, and was similar to the absorption spectrum of photosytem‐2 particles. These data suggest that the electron transfer driven by photosystem 2 is essential for the activation of the water‐splitting system in the chloroplasts of intermittently illuminated lea

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03127.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractFour cellular RNA polymerases have been partially purified from cultures ofVerticillium agaricinumusing DEAE‐cellulose chromatography. Polymerases 1 and II are probably localised in the nucleolus and non‐nucleolar portion of the nucleus respectively, while III and IV are probably mitochondrial in origin. DNA stimulation and dependency on the four ribonucleoside triphosphates were shown to be characteristic of all four polymerases. The products of their activity were sensitive to ribonuclease digestion and to KOH hydrolysis. The time course study of all four polymerases showed a linear increase for 1 min followed by a plateau and a rapid decrease after 5 min.Illumination of 4‐day‐old cultures increases the activity of RNA polymerase I, II, and III while only that of I and III is increased in 7‐day cultures. There is a similar increase in the amount of carotenoids produced by 4‐ and 7‐day‐old illuminated cultures. It is tempting therefore to suggest that ribosomes or mitochondria or both may be implicated in light‐ind

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03128.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractConditions are described for measuring anthranilate synthetase, anthranilate‐PRPP‐phosphoribosyl transferase, N‐5′‐phosphoribosyl anthranilate isomerase, indole‐3‐glycerol phosphate synthetase and tryptophan synthetase in crude extracts fromTriticum aestivum(wheat) plants. Only the last enzyme has been measured before in extracts from green plants. The extractable quantities of each enzyme in all plant parts at all stages of growth were sufficient to synthesize the amount of tryptophan present within the same tissue in 48 h. Anthranilate synthetase activity was the lowest of the five enzyme activities and was the only one inhibited by tryptophanin vitro, indicating that this enzyme may be the control point in tryptophan biosynthesis in

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03129.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe abscisic acid content of the mature shoot tissue of vigorousPrunus avium, medium sizedPrunus cerasusand dwarfingPrunus cerasusself (S) was estimated by spectropolarimetry and gas chromatography. There is no correlation between the levels of ABA found in the tissue and the dwarfing potential of the trees investigated. However,Prunus ariumstem tissue shows the lowest sensitivity to ABA, whereas the explants of normal and dwarfingPrunus cerasusexhibit a stronger inhibition.

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03130.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY