摘要:

AbstractExperiments were carried out with three seed lots ofBetula nanacollected in 1967 from different localities in Norway. Seeds were stratified for 0‐20 days in dark at +2‐+3 °C on filter papers moistened with distilled water, or treated with solution of GA3for 24 h at room temperature, and then moved into special germination boxes that were placed in different temperature conditions.All the seed lots had conditional dormancy. Quantitatively, the dormancy was different in the different seed lots (pronenances), but there were no qualitative difference in the reaction to stratification gibberellic acid and to germination temperature. Differences between seed lots may have been due to different stage of seed development.The dormancy was deepest at low temperatures(12 and 15°C) decreasing gradually with increasing temperature (to 24 °C). The dormancy was effectively broken by a short stratification (from 5 to 15 days), and by treatment with gibberellic acid. The deeper the dormancy and the lower the germination temperature the longer the stratification that was needed for maximum germination. Similarly, the concentration of GA3needed for maximum germination increased with decreasing temperature and with increasing do

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06432.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractThe isoenzyme patterns of individual Xanthium leaves at various stages of development were determined by acrylamid electrophoresis. The Leaf Plastochron Index was used to measure leaf and plant age. The nature of the changes occurring during leaf development differed from enzyme to enzyme and from gfrom isoenzyme to isoenzyme; for instance, one of the glucose‐6‐phosphate dehydrogenases was peculiar to very young leaves, another to rapidly expanding leaves, and yet another to still older ones. On the other hand, the number of amylase isoenzymes merely increased with leaf age. Many of the changes in the isoenzyme patterns coincide with the cessation of cell division in the leaf or with the completion of leaf growth. The particular isoenzyme patterns of a given leaf depended on both leaf and plant age. While the isoenzyme patterns of leaves from maximum aldolase activity per unit protein and at a later stage than the leaves from the vegetative pla

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06433.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractPhotoinduction of NADP‐linked glyceraldehyde‐3‐phosphate dehydrogenase activity in etiolated pea seedlings was investigated in the presence of various concentrations of four inhibitors of protein synthesis (cycloheximide, actinomycin D, chloramphenicol and puromycin) and one photosynthesis inhibitor (DCMU), and compared with increase in chlorophyll and total protein contents. The enzymatic activity and chlorophyll showed similar responses to the action of the antibiotics, whereas they were not significantly affected by the presence of

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06434.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractThe dependence of the nitrogen fixing system in the root nodules of pea plants (Pisum sativum) L. cv. Torsdag II) on light induced reactions was studied. The pots of the inoculated pea plants, after the nolules had fixed nitrogen for a fornight, were transferred to a dark room. The control plants were kept under normal lighting conditions.The decay of leghemoglobin was measured after photosynthesis had ceased. In the dark the red nodules turned green in three days, when about half of the haem had been broken down. The plants in normal lighting conditions had maintained the red nodules. The appearence of leghemoglobin and bacteroids was simultaneouos. In normal lighting conditions the number of bacteroids was about 1.6 × 108per g fresh nodules. The appearance of leghemoglobin and bacteroids was simultaneous. In normal lighting conditons the number of bacteroids was bout 1.6 × 108per g fresh nodules. At the same time as the nodules turned green in the dark most of the bacteroids disappeared and the number of rod‐shaped bacteria increased. After five days int the dark thenumber of bacteria of the green nodules was 2.2 × 108per g fresh nodules. A large increase of of bacteria in the nodules is one of the results after the termination of effective symbiosis.Quantitative estimations were made with an automatic amino acid analysator of the amino acid composition in the root nodules of pea plants grown in the light and of pea plants grown in the dark. Altogether 27 amino acids and amides and 3 unknown ninhydrin positive compounds were found in the free amino acid fraction. In the red N‐fixing nodules asparagine, the amide of aspartic acid, was the most prominent (more than 50 per cent of the total amino acid fraction), indicating the energy charge of the nitrogen fixation. 5 days in the dark affected the proportions of the amino acids as follows. Asparagine, homoserine, γ‐aminobutyric acid and ethanolamine were decreased and the most of the others increased.In the hydrolysate of the non‐soluble protein fraction 25 amino acids could be detected. The proportions of the amino acids in the root nodules of light‐grown and dark‐grown pea plants were very similar. Hydroxyproline and α, γ‐diaminopimelic acid (DAP) were found in these fraction. Most of the DAP was contained in the peptide fraction. Also hydroxyproline was found to a small extent. It was assumed that the amino acids in this fraction were derived from the peptides of both plant

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06435.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractThe blue‐green algaNostoc commune584 displays a photocontrolled developmental cycle similar to that described forN. muscorumA by Lazaroff and Vishniac (1961). In both species white fluorescent light acts at the same stage, ragulating the development of motile trichomes from sheathed aseriate colonies. However white light blocks this step in N. commune 584, whereas the formation of motile trichomes is promoted by white light in N. muscorum A. Light‐grown (aseriate) cultures in N. commune 584 were used to determine the action spectra for photomorphogenesis. Green light (max 520 nm) inhbited aseriate colony breakage, and red light (max 640 nm) promoted colony breakage and the differentiation of motile trichomes. On a quantum basis green light was about 3 times more effective than red light. The morphogenetic effects of either red or green light were reversible by irradiation with the other color of light. Repeated photoreversibility was observed, and the algal culutres responded only to the color of the last irradiation in a sequence. An unidentified substance is excreted into the media of motile cultures of both N. commune 584 and N. muscorum A which promotes motility in non‐motile cultures. The motility‐promoting substances from both species are reciprocally active. Activity is lost when the media are aut

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06436.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractDialyzed extracts from sterile and nonsterile pea seedlings perform the synthesis of tryptophan from indole‐3‐glycerol‐1‐phosphate (IGP) and L‐serine. Compared with the analogous indole methabolism, there are similar dependences with regard to pH and to serine and pyridoxal‐5‐phosphate requirements, but the IGP conversion rate only amounts to one third of that measured for indole. Indole‐3‐glycerol is not metabolized by both tissue

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06437.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractEpiphytic, IAA‐producing bacteria strains were fed with14C‐tryptophan (Try).14C‐Try absorption and, after transfer to a Try‐free medium,14C‐IAA output were stated. Using 4 different methods, the14C‐Try containing bacteria were applied to the tips of sterile corn coleoptiles and the ‘diffusible’ auxin collected at the coleoptile bases by means of agar blocks.14C‐IAA was detected in the agar blocks. Sterile coleoptiles the tips of which were wupplied with14C‐Try also deliver some14C‐IAA at their bases, but much less than both sterile coleoptiles supplied with14C‐Try‐containing bacteria and nonste

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06438.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractExcised wheat roots in culture release a substance inhibitory to their growth and which can be absorbed on activated charcoal. This growth inhibitor can be isolated in pure form by diethylether extraction followed by DEAE cellulose and thin‐layer chromatography. At very low concentration it inhibits lateral root development. The significance of this inhibitor to the problem of the continuous growth of cultured wheat roots is discusse

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06439.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractChanges in the soluble nitrogen compounds after application of 3‐amino‐1,2,4‐triazole (amitrole) to amitrole susceptible and amitrole resistant ecotypes ofCirsium arvensewere investigated. One day after treatment with amitrole the concentration of all nitrogen compounds tested in the leaves of the susceptible ecotype was reduced, but none was eliminated. Five days after treatment the concentration of the same compounds increased in the leaves above the control (0 amitrole) concentration. The resistant ecotype had less change in nitrogen compounds than did the susceptible ecotype. Changes in the soluble nitrogen compounds in the stem and root fraction were less than in the leaf fraction. The authors suggest a two phase reaction of the soluble nitrogen compounds due to amitrole treatment. It is concluded that the primary biochemical lesion of amirole in mature Cirsium arvense is not the elimination of glycine, serine, or any other soluble nitrogen com

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06440.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractIn the presence of large accumulations of protochlorophyllide, derived from exogenous δ‐aminolevulinic acid, chlorophyll synthesis in excised leaves of two varieties of barley was less than in untreated leaves. In oat leaves the accumulated protochlorophyllide, from exogenous δ‐laminolevulinic acid, stimulated chlorophyll synthesis to above the control level. — These relationships could only be demonstrated when phtodestruction of pigments was minimised by the use of flash illumination (2 milliseconds every 3 minutes). — These was no evidence fromin vivoabsorption spectra that the pigments in the barley leaves were different to those in leaves studied by other workers. However, the presence of the accumulated protochlorophyllide appeared to prevent the shift of the chlorophyll absorption maximum from 673 nm to 677 nm. — Possible mechanisms of inhibition ar

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1970.tb06441.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY