Showing papers in "Plant and Cell Physiology in 1980"
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TL;DR: A cell line of Nicotiana tabacum L. var.
Abstract: A cell line of Nicotiana tabacum L. var. Wisconsin 38 was selected (S-10 cells) which is capable of growth in medium containing 10 g liter(-1) NaCl. The fresh and dry weights of S-10 cells at stationary phase in medium containing 10 g liter(-1) NaCl were about 60 and 100% respectively, of that of S-10 cells grown without NaCl. When cells normally maintained in the absence of the salt (S-0 cells) were transferred to medium containing 10 g liter(-1) NaCl, they underwent a 14-day lag period before growth could be detected and they reached stationary phase 36 days after inoculation compared to 14 days for S-10 cells. At stationary phase, fresh and dry weights of S-0 and S-10 cells were the same in the presence of salt. The S-0 cells exhibited a reduced growth rate once growth began in medium with 10 g liter(-1) NaCl. The cell mass doubling time of S-0 cells in medium with 10 g liter(-1) NaCl was 4 days compared to 1.2 days for these cells grown in the absence of the salt and 1.6 days for S-10 cells grown in medium with 10 g liter(-1) NaCl. The resistance of the salt-selected cells was stable in the presence of the salt. However, after 5 cell mass doublings following transfer into medium without NaCl, these cells lost their resistance to salt and responded to NaCl like the cell population (S-0 cells) which had not been selected for growth on NaCl.
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TL;DR: The phototransformation of undegraded pea phytochrome from its red-light-absorbing form to its far-red- light- absorption form was examined at 2-4°C after laser flash excitation using a custom-designed multichannel transient spactra analyzer.
Abstract: The phototransformation of undegraded pea phytochrome, which was estimated to be about 30 to 40% pure, from its red-light-absorbing form to its far-red-light-absorbing form was examined at 2-4°C after laser flash excitation at 655 nm using a custom-designed multichannel transient spactra analyzer. A difference spectrum measured 10 μsec after the flash showed an absorbance increase at 692 nm, a decrease at 660 nm and a slight decrease at 604 nm. With time in darkness, the peak at 692 nm gradually decreased in magnitude and shifted to 695 nm. A decay curve of absorbance at 692 nm between 10 and 500 μsec after the flash could be resolved into two reaction components, one proceeding with a rate constant of 46,000 sec(-1) and the other with one of 2,500 sec(-1). The faster component has not been reported previously. Difference spectra also indicated that a small but significant increase in absorbance between 400 and 410 nm and decrease around 360 nm took place 10-260 μsec after the flash.
67 citations
TL;DR: Although the amount of wall xyloglucan increased during cell growth, the ratio of xylglucan to total hemicellulose remained constant at about 50%, and the results from methylation analysis and fragmentation analysis indicated that each xylogucan was mainly constructed of two kinds of oligosaccharide repeating units.
Abstract: Two kinds of xyloglucans were obtained from the cell walls of suspension-cultured soybean cells together with an additional one from the culture medium. They had almost the same properties, i.e., sugar composition, [α]d value, and iodine staining spectrum. The molecular weights of the two kinds of wall xyloglucans were 180,000 and 60,000, whereas that of the extracellular xyloglucan shifted from 60,000 to 30,000 with the progress of cultivation. The results from methylation analysis and fragmentation analysis with endoglucanase indicated that each xyloglucan was mainly constructed of two kinds of oligosaccharide repeating units, a heptasaccharide (glucose/xylose, 4 : 3) and a nonasaccharide (glucose/xylose/galactose/fucose, 4 : 3 : 1 : 1). Although the amount of wall xyloglucan increased during cell growth, the ratio of xyloglucan to total hemicellulose remained constant at about 50%.
TL;DR: The enzyme had its absorption maxima at 275, 375 and 440 nm, suggesting that pea NADH-glutamate synthase is a flavoprotein, and Sulfhydryl reagents, metal-chelatingReagents, phthalein acids and azaserine were strong inhibitors.
Abstract: Both ferredoxin-glutamate synthase (EC 1.4.7.1) and NADH-glutamate synthase (EC 1.4.1.14) were isolated separately on DEAE-cellulose chromatography from etiolated pea shoots. The latter enzyme was purified 1,400-fold by ammonium sulfate fractionation and column chromatographies of DEAE-cellulose, Sephadex G-200 and blue-Sepharose. The enzyme had a molecular weight of 220,000 and an isoelectric point of 4.3. The optimum pH was 7.6. Apparent Km values for l-glutamine, 2-oxoglutarate and NADH were 400, 37 and 4 µm, respectively. The enzyme had its absorption maxima at 275, 375 and 440 nm, suggesting that pea NADH-glutamate synthase is a flavoprotein. It showed NADH-diaphorase activity toward ferricyanide and 2,6-dichlorophenol indophenol as the electron acceptor. Sulfhydryl reagents, metal-chelating reagents, phthalein acids and azaserine were strong inhibitors. Ammonium and phosphate ions enhanced the enzyme activity.
TL;DR: In this paper, the effects of COPPER CHLoride on PHOTOSYNTHETIC ELECTRON-TRANSPORT and CHLOROPHYLL-PROTEIN COMPLEXES of SPINACIA-OLERACEA were investigated.
Abstract: EFFECTS OF COPPER CHLORIDE ON PHOTOSYNTHETIC ELECTRON-TRANSPORT AND CHLOROPHYLL-PROTEIN COMPLEXES OF SPINACIA-OLERACEA
TL;DR: Changes in sugar compositions and the distribution pattern of the molecular weight of cell wall polysaccharides during indole-3-acetic acid (IAA)-induced cell elongation were investigated and an important role of galactan turnover in cell wall extension is discussed.
Abstract: Changes in sugar compositions and the distribution pattern of the molecular weight of cell wall polysaccharides during indole-3-acetic acid (IAA)-induced cell elongation were investigated. Differential extraction of the cell wall and gel permeation chromatography of wall polysaccharides indicated that galactans, polyuronides, xylans, glucans and cellulose were present in the azuki bean epicotyl cell wall. When segments were incubated in the absence of sucrose, IAA enhanced the degradation of galactans in both the pectin and hemicellulose fractions, whereas to some extent it enhanced the polymerization of xylans and glucans in the hemicellulose fraction and an increase in the amounts of polyuronides in the pectin fraction and of a-cellulose. In the presence of 50 nw sucrose, IAA caused large increases in the amounts of all the wall polysaccharides, and enhanced the polymerization of galactans, xylans and glucans in the hemicellulose fraction. These results and an important role of galactan turnover in cell wall extension are discussed.
TL;DR: Changes in the ultraviolet absorption spectrum took place when coupling factor 1 of spinach chloroplasts (CF1) was mixed with ATP or ADP, and PPi effectively inhibited the absorbance change induced by ADP and Mg(2+).
Abstract: Changes in the ultraviolet absorption spectrum took place when coupling factor 1 of spinach chloroplasts (CF1) was mixed with ATP or ADP. The difference spectrum had a maximum at about 278 nm and a minimum at about 250 nm. The profile of the difference spectrum inidcates a shift in the absorption spectrum of the ADP or ATP bound to CF1. The ratio of the maximal absorbance change at about 278 nm to the absorbance of CF1 at that wavelength was 0.027-0.048. The molar concentration of nucleotide required to give the maximal absorbance change was 2-3 times that of CF1 when Ca(2-) or Mg(2+) was present. AMP induced no significant spectral change. When ADP was added, the absorbance change reached a plateau within a few minutes if Mg(2-) or Ca(2+) was present. The absorbance change induced by ATP reached a plateau within a few minutes only when Ca(2+) was present. In the presence of Mg(2+), it reached a plateau of nearly the same level, but at a slower rate. The absorbance change was reduced in the presence of EDTA. PPi effectively inhibited the absorbance change induced by ADP and Mg(2+).
TL;DR: The level of the soluble sugars in calcium deficient leaves increased to more than 10-fold that in the control at the late stage of treatment, and the contents of soluble and bound calcium, in contrast to soluble sugars, decreased only in the young leaves of calcium deficient plants.
Abstract: To determine the metabolic role of calcium we grew cucumber plants without calcium. Symptoms of leaf injury such as chlorosis and marginal curling appeared a few days after the removal of calcium. The level of the soluble sugars in calcium deficient leaves increased to more than 10-fold that in the control at the late stage of treatment. In contrast, the level of the soluble sugars in the root decreased because of the calcium deficiency. The contents of soluble and bound calcium, in contrast to soluble sugars, decreased only in the young leaves of calcium deficient plants. The content of each soluble sugar measured by liquid chromatography was stable in the control leaves during treatment. Changes in sucrose, fructose, glucose, maltose and galactose in calcium deficient leaves were similar to the change in the total soluble sugars. The increases in stachyose and the mixture of raffinose and cellobiose took place only at the late stage of calcium starvation. The starch content in calcium deficient leaves was somewhat higher than that of the control, except for the remarkable decrease at the late stage. α-Amylase activities were not altered much in either the control or the calcium deficient plant during 5 days of treatment, but a clear increase took place at the late stage of calcium starvation. The reason for the distinct increase in the soluble sugars in calcium deficient leaves could be explained by the decline in transport due to the calcium deficiency.
TL;DR: With first and second passage calli induced from seedlings of Digitalis purpurea, D. lanata, the total contents of digitoxin equivalents decreased but those of digoxin equivalents slightly increased, and shoot-forming calli accumulated considerable amounts of cardenolides, which were assayed as digitoxin and Digoxin equivalents by radioimmunoassay.
Abstract: With first and second passage calli induced from seedlings of Digitalis purpurea, D. lanata, D. lutea, D. mertonensis, D. ambigua and D. ferruginea Gigantea and those induced from leaf discs of D. purpurea and D. lanata, the contents of digitoxin and digoxin equivalents were assayed and compared with the contents involved in the inocula. Although the total contents of digitoxin and digoxin equivalents in the first passage calli induced from seedlings varied between zero and nine times as high as in the original seedlings, those in the second passage calli were almost undetectable. The total contents of digitoxin equivalents in the first passage calli induced from leaf discs of D. purpurea were approximately equal to those in the original leaf discs, but those in the second passage calli were less than those in the inocula. In the first passage calli induced from leaf discs of D. lanata, the total contents of digitoxin equivalents decreased but those of digoxin equivalents slightly increased. However, in the second passage calli, the amounts of both cardenolides decreased. Root-forming calli accumulated no more digitoxin nor digoxin equivalents than completely dedifferentiated calli. However, shoot-forming calli accumulated considerable amounts of cardenolides, which were assayed as digitoxin and digoxin equivalents by radioimmunoassay.
TL;DR: More than 70% flowering was observed in Spirodela polyrrhiza SP20 under long and short days, when fronds were grown in a medium supplemented with 5×10-5 M salicylate (SA).
Abstract: More than 70% flowering was observed in Spirodela polyrrhiza SP20 under long and short days, when fronds were grown in a medium supplemented with 5×10-5 M salicylate (SA). To our knowledge this is the first report of such profuse flowering of this duckweed in vitro. Besides flowering, SA also affected the multiplication rate, anthocyanin and chlorophyll contents, and gibbosity. Aspirin had an effect similar to that of SA.