摘要:

AbstractFreezing and thawing of winter rape leaves was found to cause a marked decrease of total phospholipid content in general, and that of phosphatidyl choline in particular. In the highly injured leaves the decrease of phosphatidyl choline was irreversible, and it was accompanied by a marked increase of phosphatidic acid. In the slightly damaged leaves no phosphatidic acid accumulation was detected, irrespective of phosphatidyl choline decrease. Instead of phosphatidic acid, the phosphatidyl glycerol or an unidentified P‐containing lipid increased after thawing in leaves hardened to the first (Tk50=−8°C) or to the second (Tk50=−13.5°C) level, respectively. Frost hardening was found to promote phospholipid recovery after freezing and to increase phospholipid content, including that of phosphatidyl choline and phosphatidyl ethanolamine. Possible association of frost hardening with modified phospholipase‐D properties is

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1980.tb03242.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractProtoplasts ofDaucus carotaL. cultured in a synthetic liquid medium resumed cell division after about 4 days of cultivation. During this lag period, nucleic acid and protein showed only slight increases but the protoplasts commenced cell‐wall regeneration soon after the removal of lytic enzymes. The originally spherical protoplasts became ellipsoidal before they underwent division. Radioactive glucose andmyo‐inositol were readily utilized by the protoplasts. Most of the radioactivity, however, appeared in extracellular polysaccharides and only a small portion was deposited in the regenerated wall. The sugar composition of new cell wall, as studies by chemical analysis and incorporation of labelled precursors, was shown to be considerably different from that of normal cell w

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1980.tb03243.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractChloroplasts isolated from pine needles were found to be inactive with respect to CO2fixation. Since it was suspected that pine needles may contain substances inhibitory to photosynthesis, studies were carried out using photosynthetically active isolated spinach chloroplasts and chloroplasts isolated from pine needles. When isolated pine chloroplasts were suspended in buffer and were added to isolated spinach chloroplasts they inhibited photosynthetic CO2fixation. When the pine chloroplasts were separated from the medium by centrifugation, the separated pine chloroplasts severely inhibited CO2fixation by isolated spinach chloroplasts, but the supernatant solution from the pine chloroplasts was not inhibitory. As little as 5% pine chloroplasts (based on chlorophyll content) produced 50% inhibition of CO2fixation by the spinach chloroplasts. Studies of fixation of14C‐labelled CO2by spinach chloroplasts were carried out in which after 5 min photosynthesis the pine chloroplasts were added. It was found that the subsequent inhibition of spinach CO2fixation was neither due to any effect on the rate of export of photosynthetic metabolites from the chloroplasts to the medium, nor to a direct effect on the RUBP carboxylase reaction. The principal effect was found to be an inhibition of the conversion of fructose‐1,6‐bisphosphate and sedoheptulose‐1,7‐bisphosphate to the respective monophosphates and inorganic phosphate. From this finding it was concluded that a principal effect of the inhibition by pine chloroplasts is probably an inhibition either directly or indirectly of the bisphosphatase enzymes in the spinach chloroplasts. Based on its distribution between organic and aqueous acidic or neutral solutions, the inhibitory factor of the pine chloroplasts must be lipophilic. Most of the factor could be transferred to an aqueous phase in a strongly alkaline solution. Following subsequent acidification of the aqueous phase the activity could be completely transferred back into the organic phase. This procedure allowed for separation of the inhibitory factor from most of the pigments and other lipophilic substances present in the pine chloroplasts and yielded a preparation which could be subsequently fractionated by thin layer chromatography. UV absorption was found in two fast moving spots and at the origin. The fastest running spot from the thin layer chromatography plate was found to be the one containing most of the inhibitory

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1980.tb03244.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractRoot formation was found to extend the life‐span of excised cotyledons ofHelianthus annuusL. markedly. Excised cotyledons of 12‐day‐old plants attained longer life‐span, higher root number and total root length than cotyledons excised before or after 12 days. Protein content of attached cotyledons reached a maximum level 12 days after the commencement of germination followed by a decrease. Cotyledons excised 8 days after sowing showed maximum level of protein content 44 days after excision followed by a decrease. The increase was correlated with the full development of roots. The incorporation of14C‐glycine into protein followed a pattern similar to the protein content, both in attached and detached c

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1980.tb03245.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractSomatic hybrid plants were produced by fusion of protoplasts from cell cultures of theNicotiana tabacumL. sulfur mutant Su/Su and from leaf mesophyll ofNicotiana glauca Graham.After fusion theN. glaucaprotoplasts failed to survive under the selected culture condition. From the hybrid cells light green shoots were produced. The hybrid plants exhibited intermediate characters between parental species with respect to leaf morphology, trichome density, floral structure and flower color. The chromosome number of 25 hybrid plants was 2n = 72 and bothN. glaucaandN. tabacumchromosomes were identified in the hybrids. Results of isoenzyme analysis showed bands of both parents and a specific (hybrid) band for aspartate amino‐transferase. Small subunit fraction‐1‐protein of somatic hybrids also consisted of the sum ofN. glaucaandN. tabacumbands. Leaf spot formation associated with the Su locus ofN. tabacumwas observed in somatic hy

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1980.tb03246.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractThe maternal male sterile barleymsm1with or without a dominant gene,Rfmla, which restores male fertility, was studied. Determined with SDS‐PAGE, the polypeptide pattern in the anthers of unrestoredmsm1plants remains juvenile in the middle of anther development, two major zones being absent or weak. At the stage when anther development stops inmsm1plants, the anther proteins appear to be hydrolyzed to short‐chain peptides. Restored plants, heterozygous for the restorer gene,Rfmla, behaved like the near‐isogenic normal barley, cv. Adorra. The total leaf protein pattern of young leaf tissue and the chloroplastidic membrane protein pattern are normal inmsm1cytoplasm when studied with this technique.Chlorophyllbis unnecessary for restoration byRfmla, though the restored plants have a lower chlorophyll a/b ratio than an unrestored plant in the mature stem leaf.Mature stem leaf pieces of unrestoredmsm1plants were induced to senesce with 20 mMNaCl solution. This senescence was inhibited by exogenous kinetin. Leaf pieces of restoredmsm1plants or those of near‐isogenic normal barley behaved in the same way in the NaCl solution as in distilled water. Many features of the physiology of restored plants can be explained as the functions of cytokinins.Kernels of male sterile plants have a more rapid root elongation at germination than near‐isogenic norm

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1980.tb03247.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractIn maize coleoptiles (Zea maysF1XL 640A, cv. Dekalb) canavanine and cycloheximide strongly and simultaneously inhibit cell elongation, H+extrusion and K+uptake, induced by IAA. They inhibit also, although to a much lesser degree, the same phenomena induced by fusicoccin. Cycloheximide severely depresses the incorporation of leucine into proteins, while canavanine leaves leucine incorporation almost unchanged. The data confirm that elongation, H+extrusion and K+uptake can be regarded as correlated processes; they also support the view that normal protein synthesis is essential for IAA‐induced growth, while this requirement is only partial in growth stimulated by fusicocci

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1980.tb03248.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractThe role of the oxidative pentose phosphate (PP) pathway in the dormancy‐breaking of cocklebur (Xanthium pennsylvanicumWallr.) seeds was investigated. D‐[1‐14C]‐glucose or D‐[6‐14C]‐glucose was fed to dormant and non‐dormant lower seeds or to their axial or cotyledonary segments which were imbibed for different durations, and C6/C1ratios of respired14CO2as an index of the PP pathway activity were calculated. Contrary to expectation, there was no significant difference in the C6/C1ratios between the dormant and non‐dormant seeds or segments during a water imbition period of 24 h, although the PP pathway actually operated already in an early stage of water imbibition. Also concerning the activities of G6PDH and 6PGDH, the key enzymes of this pathway, no difference between the dormant and non‐dormant seeds was found. It was thus concluded that, unlike other seeds, there is no contribution of the PP pathway to the regulation of dormancy of

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1980.tb03249.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractThe anion‐exchange capacities (AEC) of roots of intact plants of two plum clones [Marianna 2624 (Prunus cerasifera × P. munsoniana) and Myrobalan 3‐J (P. cerasifera)] were assessed with an anionic dye, eosin Y. The positively charged eosin‐specific adsorption sites were metabolically dependent and also affected by nutrient status. Myrobalan 3‐J roots adsorbed twice as much exchangeable NO3as did Marianna 2624. Since we previously showed that net nitrate uptake by Myrobalan 3‐J persisted at half the ambient nitrate concentration as that characteristic of Marianna 2624, the data provide circumstantial support for a functional role of labile anion binding in active uptake at dilute concentrations of ambie

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1980.tb03250.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractChlorophyll‐free leaf protein concentrates for human consumption can be produced after separation of the chlorophyll‐associated protein from the rest of the leaf protein. This protein separation was studied in four plant species using heat fractiona‐tion. Press juice was prepared on a laboratory scale from field grown Atriplex hortensis, Brassica napus. Brassica oleracea and Helianthus annuus. Some further experiments were made with greenhouse grown plant material. After adjustment of pH to values between 4.0 and 8.0 the press juice was heated in water baths at 20, 35, 40, 45, 50, 55 and 60°C with or without 20 min holding time at appropriate temperature. Thereafter the juices were briefly centrifuged at 2500g. The protein content of the sediment was determined and the colour of the supernatant was observed.The species showed different protein sedimentation patterns, especially at neutral and weakly alkaline pH. Brassica napus had rapidly sedimenting proteins, low temperature was sufficient for complete sedimentation of chlorophyll‐associated proteins and gave a high percentage of the total press juice protein as chlorophyll‐free protein. Atriplex hortensis had slowly sedimenting proteins irrespective of temperature, required high temperature for complete sedimentation of chlorophyll‐associated proteins and gave a low percentage chlorophyll‐free proteins. Brassica oleracea and Helianthus annuus showed intermediated properties. Reasons for these differences among the species

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1980.tb03251.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY