Plant Physiology

Rabinowitz, Hannah; Reisfeld, Avi; Sagher, Daphna; Edelman, Marvin

doi: 10.1104/pp.56.3.345pmid: 16659300

Abstract Ribulose 1,5-diphosphate carboxylase (RUDPcase) from autotrophically grown Euglena gracilis was purified to homogeneity as measured by analytical ultracentrifugation, polyacrylamide gel electrophoresis, and immunoprecipitation reactions. The enzyme represented about 9% of total protein and 24% of soluble protein in the autotrophic cell. Light-grown, heterotrophic cells seemed to contain considerably less RUDPcase. Native carboxylase from autotrophic Euglena showed an s20, w at low protein concentrations of 17 to 17.5, suggesting a molecular weight of >500,000 daltons. Upon denaturation, the enzyme dissociated into two subunits having different amino acid compositions and molecular weights of 59,000 and 12,000 daltons. Based upon the amino acid mass ratios, a quaternary organization of 7 to 8 large and 8 to 10 small subunits per native enzyme molecule was indicated. The phylogenetic relationship of carboxylase from Euglena and from three higher plants was investigated. In general, the size, subunit formation, and quaternary structure of RUDPcase from the various sources seemed to be similar. A partial immunochemical reaction between anti-RUDPcase serum from Euglena and the enzymes from lettuce, cucumber, and New Zealand spinach suggested that the algal and higher plant carboxylases were related but not identical. This was borne out by amino acid analyses which showed a close correspondence between the large, but not the small, subunits of Euglena and lettuce. This content is only available as a PDF. © 1975 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)

Mancinelli, Alberto L.; Rabino, Isaac

doi: 10.1104/pp.56.3.351pmid: 16659301

Abstract Under continuous far red light, anthocyanin synthesis in young, dark-grown cabbage seedlings (Brassica oleracea cv. Red Acre) is irradiance-dependent and fails to follow the reciprocity (irradiance × time = constant) relationships. Under intermittent far red treatments extended over a prolonged period of time, anthocyanin synthesis becomes dose dependent, and reciprocity relationships are valid. Intermittent far red treatments with short dark intervals between successive irradiations are as effective as continuous treatments, if the total radiation doses applied with the two types of treatments are equal and are applied over equally long periods of time. The high effectiveness of inter-mittent treatments, the dose dependence, and the validity of the reciprocity relationships suggest that cycling between red-absorbing form of phytochrome and far red-absorbing form of phytochrome and the formation of electronically excited far red-absorbing form of phytochrome, or the involvement of a second photoreactive system, besides phytochrome, may play only a minor role in high irradiance reaction anthocyanin synthesis brought about by prolonged exposures to far red irradiation. 2 Present address: Division of Biological Sciences, SUNY at Stony Brook, N.Y. 11794. 1 Research was supported in part by National Science Foundation Grants GB-35460 and BMS74-19976 to A.L.M. This content is only available as a PDF. © 1975 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)

Leguay, Jean-Jacques; Guern, Jean

doi: 10.1104/pp.56.3.356pmid: 16659302

Abstract Using suspension-cultured Acer pseudoplatanus cells requiring 2,4-dichlorophenoxyacetic acid for growth, the dependence of the population doubling time and the maximum increase in cell population density on the auxin concentration was studied. It appears that in the range of 2,4-dichlorophenoxyacetic acid concentration from 4 × 10−8 to 4 × 10−6 M, the rate of cell division during the logarithmic growth phase is independent of the auxin concentration, while the maximum number of cell generations obtained is limited by the initial auxin concentration. The significance of these two aspects of auxin action are discussed. 1 This work was supported by the Centre National de la Recherche Scientifique, Equipe de Recherche Associée no 486. This content is only available as a PDF. © 1975 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)

Doss, Robert P.

doi: 10.1104/pp.56.3.360pmid: 16659303

Abstract Short term inhibitor treatment can be used to examine the processes that occur during an inductive dark period in the short day plant Lemna perpusilla Torr., strain 6746. Several inhibitors of protein biosynthesis are most effective in reducing per cent flowering when treatment occurs over the 2-hour intervals beginning at the 12th hour or the 14th hour of a 8 (16) photoperiodic cycle. The antimetabolite, 5-fluorouracil, is most effective when treatment occurs early in the dark period. Evidence is cited suggesting that distilled water incubation inhibits flowering by interfering with protein biosynthesis. 1 This was supported in part by a Chancellor's Patent Fund Grant, a Priority C Research Grant, and a National Defense Education Act Predoctoral Fellowship. 2 A portion of this report is taken from a dissertation submitted in partial fulfillment of the requirements for a Ph.D. degree in plant physiology at the University of California, Davis. This content is only available as a PDF. © 1975 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)

Key, Joe L.; Silflow, Carolyn

doi: 10.1104/pp.56.3.364pmid: 16659304

Abstract The occurrence and distribution of poly(A) sequences in the RNA of soybean (Glycine max var. Wayne) have been studied. Only one of the two species of AMP-rich RNA contains poly(A). D-RNA does not contain detectable poly(A) sequences. The TB-RNA is the poly(A) RNA in this system. At least a part (up to 50% or more) of the mRNA in polyribosomes contains a poly(A) sequence. The poly(A) RNA is heterodisperse in size but has a mean size of approximately 18S (2,000 nucleotides) in urea and formamide gels. The poly(A) fragment resulting from ribonuclease A and T1 digestion migrates as a broad band overlapping the 4 to 5.8S regions of the gels with a mean size of somewhat greater than 5S. No evidence was found for the occurrence of a discrete oligo(A) fragment in the poly(A) RNA; however, oligonucleotides which migrate faster than the poly(A) fraction were observed in preparations which were not bound to oligo(dT) cellulose prior to electrophoresis. This oligonucleotide region was enriched in AMP (up to about 65%) as would be expected after ribonuclease A and T1 digestion. 1 This research was supported by United States Public Health Service Research Grant CA 11624 from the National Cancer Institute and by Atomic Energy Commission Contract AT(38-1)643. This content is only available as a PDF. © 1975 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)

Lakso, Alan N.; Kliewer, W. Mark

doi: 10.1104/pp.56.3.370pmid: 16659305

Abstract Phosphoenolpyruvate (PEP) carboxylase activity in immature `Carignane' grape berries (Vitis vinifera L.) had a temperature optimum of about 38 C, whereas malic enzyme activity rose with increasing temperature between 10 and 46 C. In vitro temperature inactivation rates for the PEP carboxylase were markedly greater than for the malic enzyme activity. From the simultaneous action of malic acid-producing enzymes (PEP carboxylase and malic dehydrogenase) and malic acid-degradating enzyme (malic enzyme) systems at different temperatures, the greatest tendency for malic acid accumulation in immature grape berries was at 20 to 25 C. Time-course measurements of enzymic activity from heated, intact berries revealed greater in vivo temperature stability for the malic enzyme activity than for the PEP carboxylase activity. 2 Present address: Department of Pomology and Viticulture, New York State Agricultural Experiment Station, Geneva, N.Y. 14456. 1 This work was supported in part by a National Science Foundation Traineeship to A.N.L. This report is from a dissertation submitted by A.N.L. in partial fulfillment of the requirements for the Ph.D. degree at the University of California, Davis. This content is only available as a PDF. © 1975 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)

Jacobs, Mark; Ray, Peter M.

doi: 10.1104/pp.56.3.373pmid: 16659306

Abstract Like indoleacetic acid, buffers of acidic pH, which stimulate elongation of pea (Pisum sativum var. Alaska) stem tissue, induce the appearance within the tissue of a watersoluble xyloglucan polymer that probably arises from previously deposited wall material. Neutral pH buffers, which inhibit the elongation response to indoleacetic acid in this tissue, inhibit indoleacetic acid-induced increase in soluble xyloglucan. The findings provide further evidence that release of soluble xyloglucan from the cell walls of pea results from the biochemical action on the cell wall that is responsible for wall extension. The data also indicate that treatment of tissue with either auxin or acidic pH has a similar biochemical effect on the cell wall. This is consistent with the H+ secretion theory of auxin action. 2 Present address: Department of Biology, Swarthmore College, Swarthmore, Pa., 19081. 1 This research was supported by a grant to P.M.R. from the National Science Foundation. This content is only available as a PDF. © 1975 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)

Glass, Anthony

doi: 10.1104/pp.56.3.377pmid: 16659307

Abstract The dynamics of changes in K+ influx across the plasmalemma and of internal K+ concentrations [K+]1 of intact barley (Hordeum vulgare) roots were examined as the roots were converted from `high-salt' to `low-salt' roots. Following the transfer of plants grown in 0.5 mm CaSO4 solutions plus various concentrations of KCl to 0.5 mm CaSO4 solutions, influx rates increased and internal K+ concentrations declined as a function of time and the initial K+ status of the tissue. The relationship between plasmalemma influx and [K+]1 was examined over a wide range of [K+]1 values by growing intact plants in various concentrations of KCl. Plasmalemma influx was inversely correlated with the square of [K+]1. A model for the regulation of plasmalemma influx by [K+]1 is considered. This content is only available as a PDF. © 1975 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)

Flint, Dennis; Ayers, George S.; Ries, Stanley K.

doi: 10.1104/pp.56.3.381pmid: 16659308

Abstract The time of synthesis, the molecular weight, and the relative glutamine-glutamate and proline to leucine ratios of the endosperm proteins of wheat (Triticum aestivum L. cv. Logan) were determined using a sodium dodecyl sulfate-polyacrylamide gel technique. In general, synthesis of most proteins occurred through much of the maturation of the seed, but past 20 days the rate of synthesis of the high molecular weight proteins declined more rapidly than those of lower molecular weight. The synthesis of at least one protein occurred only late in seed maturation. Several of the high molecular weight proteins had glutamate-glutamine to leucine ratios higher than the remainder of the proteins. No evidence for proteins of a polyglutamine-glutamate and/or proline nature was found. 2 Present address: Shell Development Company, Modesto, Calif. 95352. 1 Michigan Agriculture Experiment Journal Article No. 7111. This content is only available as a PDF. © 1975 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)

Juneja, Prem S.; Pearcy, Susan C.; Gholson, Robert K.; Burton, Robert L.; Starks, Kenneth J.

doi: 10.1104/pp.56.3.385pmid: 16659309

Abstract (14C)Benzyl alcohol was administered either by uptake through the roots or by injection directly into the stems of wheat (Triticum aestivum L. em Thell), sorghum (Sorghum bicolor. L Moench) and two strains of barley (Hordeum vulgare L.). One strain of barley was susceptible to the greenbug (Schizaphis granium Rondani), and the other was greenbug-resistant. In all four plants, several radioactive metabolites were formed. The major neutral metabolite has been identified as benzyl-β-d-glucopyranoside. This glucoside was found to have no biological activity against the greenbug under conditions in which the parent compound, benzyl alcohol, inhibits the reproduction of this insect pest. 2 Present address: Winton Hill Technical Center, Proctor and Gamble Company, Cincinnati, Ohio 45224. 1 Journal Article J 2939 of the Agricultural Experiment Station, Oklahoma State University. This research was supported in part by United States Department of Agriculture Contract No. 12-14-100-10, 439 (34). This content is only available as a PDF. © 1975 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)