Plant Physiology

Richter, Martin; Wilms, Werner; Scheffer, Fritz

doi: 10.1104/pp.43.11.1747pmid: 16656967

Abstract The exudate production of alfalfa under the conditions of the sterile flow culture was quantitatively measured. In the first 40 days 3.10−3 μmoles amino-N, 2.5 μequivalents of organic acids and approximately 10−4 μmoles of reducing sugars were liberated per plant and per day into the percolating nutrient solution. The amino acid concentration in the outflow varies according to a daily periodicity. The exudation of a colored substance also shows daily periodical variations. This pattern is different from the pattern of the amino acid exudation, however, and directly coupled to shoot illumination. Short-term 2,4-dinitrophenol additions to the nutrient lower the liberation of amino acids into the percolating solution. 1 This research was supported by the Deutsche Forschungsgemeinschaft, Bad Godesburg, Germany. This content is only available as a PDF. © 1968 American Society of Plant Biologists This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Cheng, Christina K.-C.; Marsh, H. V.

doi: 10.1104/pp.43.11.1755pmid: 16656968

Abstract The effects of gibberellic acid on lignification in seedlings of a dwarf and a tall cultivar of pea (Pisum sativum) grown under red or white light or in the darkness, were studied. Gibberellic acid (10−6-10−4 m) promoted stem elongation in both light and dark and increased the percentage of lignin in the stems of the light-grown dwarf pea. The gibberellin had no effect on the lignin content of the tall pea although high concentrations (10−4 m) promoted growth of the tall plants. Time course studies indicated that the enhanced lignification in the gibberellin-treated dwarf plants occurred only after a lag period of several days. It was concluded that gibberellic acid-enhanced ligmification had no direct relation to gibberellic acid-promoted growth. The activity of phenylalanine ammonia-lyase (E.C. 4.3.1.5) was higher in gibberellin-treated dwarf plants grown under white or red light than in untreated dwarf plants. Gibberellic acid had no detectable effect on the activity of this enzyme when the plants were grown in darkness, just as it had no effect on lignification under dark conditions. The data suggest that in gibberellin-deficient peas the activity of phenylalanine ammonia-lyase is one of the limiting factors in lignification. 2 Present address: Department of Civil Engineering, University of Massachusetts, Amherst. 1 Part of a thesis by Christina K.-C. Cheng submitted to the University of Massachusetts in partial fulfillment of the requirements for the M.S. degree. This content is only available as a PDF. © 1968 American Society of Plant Biologists This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Lavee, S.; Galston, A. W.

doi: 10.1104/pp.43.11.1760pmid: 16656969

Abstract Explants of tobacco pith taken at various distances from the apex of a mature stem show a sharp gradient in growth potential in vitro; growth is highest in the extreme apical and basal explants, and is minimal in explants removed ca. 75 cm from the apex. Calluses produced by the vigorously growing basal explants are harder and more compact than those produced from more apical explants. The gradient in growth potential is directly correlated with gradients in RNA, protein of cell sap and soluble N per unit fresh weight, but is inversely correlated with peroxidase activity. Cell size increases from apex to base of plants. The peroxidase activity of pith explants is electrophoretically resolvable into 2 isoperoxidases, moving anodically at pH 9.0. During in vitro culture, this activity rises, due to the formation of several new isozymes moving toward the cathode. The appearance of these isozymes occurs most rapidly in apical and extreme basal explants. 1 Permanent address: The Volcani Institute of Agricultural Research, P. O. Box 15, Rehovot, Israel. This content is only available as a PDF. © 1968 American Society of Plant Biologists This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Kahn, Albert

doi: 10.1104/pp.43.11.1769pmid: 16656970

Abstract Proplastids and prolamellar bodies with tubular membranes were isolated from the dark grown primary leaves of bean seedlings (Phaseolus vulgaris L.). The combination of fluorescence microscopy and negative contrast electron microscopy provided the tentative identification of protochlorophyll holochrome as a constituent of prolamellar body membranes and new evidence for solution-filled channels within the tubular membrane systems of prolamellar bodies. 1 This investigation was supported by NSF grant GB-2897. This content is only available as a PDF. © 1968 American Society of Plant Biologists This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Kahn, Albert

doi: 10.1104/pp.43.11.1781pmid: 16656971

Abstract A light flash of about 1 millisecond duration elicits tube transformation in paracrystalline prolamellar bodies as well as maximal protochlorophyll(ide) photoconversion in etiolated bean leaves (Phaseolus vulgaris L.). These findings support a more detailed hypothesis on the linkage between tube transformation and protochlorophyll(ide) photoconversion than has been offered previously. 1 This investigation was supported by NSF grant GB-2897. This content is only available as a PDF. © 1968 American Society of Plant Biologists This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Everett, Marylee; Thimann, Kenneth V.

doi: 10.1104/pp.43.11.1786pmid: 16656972

Abstract A method has been developed whereby the second positive phototropism can be observed separately from the first positive and negative phototropic responses which also occur in oat coleoptiles. Although the second positive phototropic response has often been referred to as the base response, photoreception for it is shown to occur mainly in the apical 3 mm of the coleoptile. The Bunsen-Roscoe reciprocity law, so typical of first positive phototropism, does not apply to the second positive responses, and the amount of curvature increases linearly with the duration of the stimulus. However, although this linear proportionality between stimulus duration and response is the major factor determining response at all intensities tested, the intensity of the stimulus does influence the response somewhat. The action spectrum for the response shows no activity above 510 nm and has peaks at 375 and 450 nm. In all but one particular it closely resembles the action spectrum for the first positive phototropism, and it is concluded that the same, or similar, pigments may well be the photoreceptors for both types of response. The identity of this blue light absorbing pigment is not known. 1 Supported by a pre-doctoral fellowship from the NSF. 2 Present address: Biological Laboratories, Harvard University, Cambridge, Massachusetts. This content is only available as a PDF. © 1968 American Society of Plant Biologists This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Kutacek, Milan; Galston, Arthur W.

doi: 10.1104/pp.43.11.1793pmid: 16656973

Abstract Isatin, previously shown to promote growth in green and etiolated pea stems, is converted mainly to anthranilate in those tissues; small quantities of isatate are also formed. Fed anthranilate is converted mainly to its β-d-glucoside; smaller amounts are metabolized to anthranilamide, tryptophan and kynurenine. These data provide some basis for understanding the growth promoting activity of isatin. 3 Institute of Experimental Botany, Czechoslovak Academy of Sciences, Prague 6, C.S.S.R. 1 Supported by grants from the Herman Frasch Foundation and National Institutes of Health to the second author. 2 Dedicated to Professor Hans Söding on the occasion of his seventieth birthday. This content is only available as a PDF. © 1968 American Society of Plant Biologists This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Fox, L. Raymond; Hillman, William S.

doi: 10.1104/pp.43.11.1799pmid: 16656974

Abstract Morphologically similar pea plants having a 4-fold difference in spectrophoto-metrically detectable phytochrome can be produced by pretreatment of etiolated plants with red light (R) or with red and far-red light combined (RF). A search for response differences which could be ascribed to differences in phytochrome content has resulted only in the establishment of differences due to de-etiolation. Segments of etiolated plants differ from those of plants de-etiolated by R and RF pretreatments in 2 ways. Segments from etiolated plants appear to respond rapidly to the far-red absorbing form of phytochrome (PFR), while segments from de-etiolated plants do not respond rapidly to PFR. This statement is based upon 2 observations: (i) the red light induced growth inhibition in segments from etiolated plants rapidly escapes reversibility by far-red light, while with segments from R or RF pretreated plants, the red light effect is fully reversed by subsequent far-red light for up to 2 hr; and (ii) segments from etiolated plants were inhibited to a greater degree than were segments from RF pretreated plants when various photostationary state levels of PFR were maintained for 30 or 90 min and then removed by photoconversion to PR. The in vivo nonphotochemical transformation curves of the phytochrome of etiolated and RF pretreated plants appear to differ in 2 related respects: (i) the amount of phytochrome destroyed in de-etiolated tissue is greater than that in etiolated tissue, perhaps as a result of the fact that (ii) the rate and extent of apparent reversion of PFR to PR in etiolated tissue is about twice that in de-etiolated tissue. 1 Research carried out at Brookhaven National Laboratory under the auspices of the United States Atomic Energy Commission. This content is only available as a PDF. © 1968 American Society of Plant Biologists This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Schulman, Marvin D.; Gibbs, Martin

doi: 10.1104/pp.43.11.1805pmid: 4387009

Abstract The d-glyceraldehyde 3-P dehydrogenases of spinach leaf, pea seed, and pea shoot were purified. The NADP and NAD-linked enzymes of either spinach leaves and pea shoots could not be separated. Changes in the ratio of NADP- to NAD-linked activity of the spinach leaf and pea shoot enzymes were observed during both purification and storage of crude extracts. The spinach leaf, pea shoot, and pea seed enzymes differ electrophoretically from each other and from the rabbit muscle enzyme. The pea seed and shoot enzymes contain bound nucleotide cofactor, resist proteolytic attack, have similar Michaelis-Menton kinetic constants and are competitively inhibited by d-sedoheptulose-7-phosphate and d-sedoheptulose 1,7-diphosphate. Charcoal removes the bound nucleotide from the pea seed enzyme but not from the pea shoot enzymes. NADP and NADPH were found to inhibit the reductive but not oxidative reaction catalyzed by the charcoal treated seed enzyme. The function of the pea shoot NADP and NAD-linked enzymes in chloroplast metabolism is discussed in regard to their location and catalytic properties. Although the NADP-linked activity can be assigned a primary, if not exclusive function in photosynthesis, the assignment of a distinct metabolic function to the NAD-linked activity cannot be made at present. 3 Predoctoral Fellow of the National Institutes of Health. Present address: Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106. 1 This work was generously supported by the National Science Foundation. 2 Based upon part of a thesis submitted to Cornell University in partial fulfillment of the requirements for the degree of Doctor of Philosophy. This content is only available as a PDF. © 1968 American Society of Plant Biologists This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)