Plant Physiology

Dennis, Frank G.; Lumis, Glen P.; Olien, C. Robert

doi: 10.1104/pp.50.5.527pmid: 16658210

Abstract Ice formation in stems, as determined by means of an electrophoretic mobility technique, occurs much more rapidly in azalea than in sour cherry. The difference is more marked in the bark than in the wood. Disrupting the structure of the tissues completely eliminates differences in freezing patterns, although gross anatomical differences do not appear to account for differences in species response. Microscopic examination of frozen stems indicated that little redistribution of water occurred during freezing in azalea, and the tissues were disrupted as these crystals developed. In cherry, on the other hand, water diffused to nucleating centers where crystal growth was not opposed, giving rise to “glaciers.” 2 Present address: Department of Horticultural Science, University of Guelph, Guelph, Ontario, Canada. 1 Michigan Agricultural Experiment Station Journal Article No. 5658. This content is only available as a PDF. © 1972 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)

Roberts, R. M.; Cetorelli, J. J.; Kirby, E. G.; Ericson, Mary

doi: 10.1104/pp.50.5.531pmid: 16658211

Abstract When radioactive d-glucosamine is provided to Acer pseudoplatanus cells in liquid culture in order to label those glycoproteins that contain amino sugars, it is incorporated predominantly into a crude cell wall fraction. This observation was confirmed histologically by preparing autoradiographs of thin tissue sections from plasmolyzed cells. Highly purified cell wall material from unlabeled cells has also been shown to contain small amounts of glucosamine. Similarly, about one-half of the amino sugar recovered from cultured cells of Nicotiana tabacum is present in their cell walls. In corn roots, however, the labeled glycoproteins that are formed after glucosamine incorporation are predominantly cytoplasmic and not deposited outside the protoplast. 2 To whom reprint requests should be addressed. 1 Supported by National Science Foundation Grants GB 23533 (to R.M.R.) and GB 30235 (to M. J. Chrispeels). This content is only available as a PDF. © 1972 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)

Ching, Te May; Ching, Kim K.

doi: 10.1104/pp.50.5.536pmid: 16658212

Abstract An average of 540 picomoles of total adenosine phosphates was found in the embryo of mature seeds of ponderosa pine (Pinus ponderosa Laws.) and 1140 picomoles in the gametophyte. Adenylate energy charges were 0.44 and 0.26, respectively. After stratification, total adenosine phosphates increased 7-fold and 6-fold in embryo and gametophyte, respectively, and energy charges rose to 0.85 and 0.75. During germination, total adenosine phosphates increased to a 20-fold peak on the 9th day in gametophytic tissue, parallel with the peak of reserve regradation and organellar synthesis, and then decreased. In embryo and seedling, total adenosine phosphates elevated 80-fold with two distinct oscillating increases of AMP and ADP. The oscillating increases occurred before the emergence of radicle and cotyledons during which the highest mitotic index prevailed in all tissues. Energy charges fluctuated between 0.65 at the rapid cell dividing stage to 0.85 at the fully differentiated stage of the seedling, while energy charges remained around 0.75 in the gametophyte. These data indicated that the content of adenosine phosphates of germinating seeds reflects growth, organogenesis, and morphogenesis, and that a compartmentalized energy metabolism must exist in dividing and growing plant cells. This content is only available as a PDF. © 1972 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)

Holtz, R. Barry; Stewart, Peter S.; Patton, Stuart; Schisler, Lee C.

doi: 10.1104/pp.50.5.541pmid: 16658213

Abstract The membranes of sporophore cap tissue from the cultivated mushroom, Agaricus bisporus (Lange) Sing., were isolated using discontinuous sucrose gradient ultracentrifugation of a tissue homogenate. A membrane-rich fraction was concentrated at the 1.16/1.18 g/cc interface and a mitochondria-rich fraction at the 1.18/1.20 g/cc interface. The membrane fraction was judged to be greater than 90% membrane vesicles by electron microscopy. The protein to lipid ratio of the membrane fraction was 1.1; the molar ratio of sterol to phospholipid was 0.77. The specific radioactivity of a Mg-activated ATPase was 2.5 times greater in the membrane fraction than in the homogenate. No 5′-nucleotidase or Na-K-Mg-activated ATPase activity was observed. 2 Current address: Marine Biology Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, Calif. 92037. 1 Authorized for publication as Paper No. 4144 on February 29, 1972, in the Journal Series of The Pennsylvania Agricultural Experiment Station. This content is only available as a PDF. © 1972 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)

Ward, Bailey; Myers, Jack

doi: 10.1104/pp.50.5.547pmid: 16658214

Abstract A treatment procedure using lysozyme and ethylenediaminetetracetic acid gave intact but permeable cells (permeaplasts) of Anacystis nidulans. Rates of electron transport from water to carbon dioxide, ferricyanide, 2,6-dichlorophenol indophenol, benzoquinone, and methyl viologen, and from reduced indophenol to methyl viologen were measured as a function of treatment time. Rates of oxygen evolution in complete photosynthesis and electron flow from water to methyl viologen showed rapid and parallel decline with treatment time. Electron flow from water to ferricyanide and from reduced indophenol to methyl viologen increased during the first half hour of treatment (phase 1) to 60 to 80% of the original photosynthetic rate. Longer treatment (phase 2) resulted in decreased rate of ferricyanide reduction but not in rate of methyl viologen reduction from indophenol. Electron flow from water to quinone was two to three times higher than for complete photosynthesis in intact cells. It remained high during phase 1 and declined during phase 2. Phase 1 permeaplasts apparently retain high activity for photosystems 1 and 2 photoreactions. 2 Present address: Department of Biology, University of Mississippi, University, Miss. 38677. 1 This study was supported by Grant GM 11300 from the National Institutes of Health. This content is only available as a PDF. © 1972 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)

Stewart, Cecil R.

doi: 10.1104/pp.50.5.551pmid: 16658215

Abstract Proline was metabolized when vacuum infiltrated into starved bean (Phaseolus vulgaris L.) leaves from plants previously in the dark for 48 hours, but an equivalent increase in protein proline was not observed. When 14C-proline was infiltrated into starved leaves, a large percentage of the 14C was recovered in other amino acids, organic acids, and CO2, in addition to that recovered as protein proline. However, extensive oxidation of proline was observed only if enough proline was added to increase substantially the endogenous concentration of proline. Increasing the endogenous concentration did not affect the amount of proline that was incorporated into protein. When added to leaves from plants previously in the light of near saturating intensity for more than 16 hr, very little 14C-proline was oxidized, even when a sufficient amount of proline was added to increase the endogenous concentration. Adding sucrose to starved leaves along with the proline slowed down the oxidation of proline. Thus, it appears that some carbohydrate or intermediate of carbohydrate metabolism may inhibit the oxidation of proline in leaves. Based on kinetics of labeling, the pathway of proline oxidation was by conversion to glutamic acid and subsequent metabolism to intermediates in the Krebs cycle and to CO2. This content is only available as a PDF. © 1972 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)

Loescher, Wayne; Nevins, Donald J.

doi: 10.1104/pp.50.5.556pmid: 16658216

Abstract Sugar and uronic acid residues were derived from wall polysaccharides of oat (Avena sativa, var. Victory) coleoptiles by means of 2 N trifluoroacetic acid, 72% sulfuric acid, or enzymic hydrolysis. The products of hydrolysis were reduced and acetylated to form alditol acetates which were analyzed using gas chromatography. Time-course studies of auxin-promoted changes in various wall fractions indicate that when exogenous glucose was available, increases in certain wall constituents paralleled increases in length. However, under conditions where exogenous glucose was not available, and where wall synthesis was limited, such correlations with growth were not apparent. Under these latter conditions total wall weight initially increased slightly, then decreased. These changes in weight were the net of increases in cellulose and some noncellulosic constituents and a decrease of over 75% in noncellulosic glucose. When coleoptile sections were preincubated without exogenous glucose for 8 hours to deplete endogenous wall precursors and subsequently treated with auxin, there were no detectable increases in wall weight. There was instead an auxin-promoted decrease in wall weight, and this decrease paralleled a decrease in noncellulosic glucose. There were no significant changes in other wall components. The auxin-promoted decreases in noncellulosic glucose are interpreted as a possible step in the mechanism of growth. This content is only available as a PDF. © 1972 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)

Sukumaran, N. P.; Weiser, C. J.

doi: 10.1104/pp.50.5.564pmid: 16658217

Abstract Time-temperature profiles of freezing leaves from frost-resistant (Solanum acaule Bitt.) and frost-susceptible (Solanum tuberosum L. subsp. tuberosum Hawkes) types of potatoes did not reveal any major differences. The pattern of change in resistance of leaves to low voltage, low frequency current during freezing was different in the frost-resistant and susceptible leaves. In tissue sections from both types of leaves, cells freeze extracellularly at cooling velocities lower than 5 C per minute. Cells from leaves of resistant plants showed a higher osmotic pressure but not a higher water permeability than those from susceptible plants. The extent of injury caused by even very slow freezing was greater than that caused by equivalent isopiestic desiccation, particularly in susceptible leaves. The higher osmotic pressure in cells of leaves from resistant plants can account for the greater desiccation resistance but not for the frost resistance observed. 1 Scientific journal series paper No. 7701 of the Minnesota Agricultural Experiment Station. This research was supported by a grant from the Rockefeller Foundation. This content is only available as a PDF. © 1972 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)

Murai, T.; Akazawa, T.

doi: 10.1104/pp.50.5.568pmid: 16658218

Abstract Photophosphorylation catalyzed by chromatophores prepared from Chromatium strain D was stimulated by bicarbonate. The stimulative effect was pH dependent and the lower the pH the more marked the activation. At pH 8.0, bicarbonate (8 mm) exhibited a negligible effect, whereas at pH 7.0 approximately a 5-fold activation was observed. The apparent activation constant of bicarbonate was determined to be approximately 10.2 mm, at which concentration approximately a 7-fold activation of photophosphorylation was observed. 2 Recipient of the California Foundation for Biochemical Research Fellowship. 1 This work was supported in part by research grants from the Ministry of Education of Japan (No. 560009) and the Toray Science Foundation (Tokyo). This content is only available as a PDF. © 1972 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)

Drake, B. G.; Salisbury, F. B.

doi: 10.1104/pp.50.5.572pmid: 16658219

Abstract Leaf resistance for water vapor (total diffusion resistance minus boundary layer resistance), transpiration, and leaf temperature were measured in attached leaves of greenhouse-grown Xanthium strumarium L. plants that had been pretreated for 72 hours with high (40 C day, 35 C night), or low (10 C day, 5 C night) air temperatures. Measurements were made in a wind tunnel at light intensity of 1.15 cal cm−2 min−1, air temperatures between 5 and 45 C, and wind speed of 65 cm sec−1. Leaf resistances in low temperature pretreated plants were higher (8 to 27 sec cm−1) than in controls or high temperature pretreated plants (0.5 to 3 sec cm−1) at leaf temperatures between 5 and 25 C. Thus, the pretreatment influenced stomatal aperture. 2 Present address: Radiation Biology Laboratory, Smithsonian Institution, 12441 Parklawn Drive, Rockville, Md. 20852. 1 This work in part submitted as a Ph.D. dissertation by the Senior author and supported by National Aeronautics and Space Administration Grant NGR 45-002-068. This content is only available as a PDF. © 1972 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)