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Ipomeamarone 15-hydroxylase activity was found in a microsomal fraction from cut-injured and Ceratocystis fimbriata-infected sweet potato (Ipomoea batatas Lam. cv. Norin No. 1) root tissues and its optimum pH was 8.0. The enzyme reaction required O(2) and NADPH. The K(m) values calculated for ipomeamarone and NADH were... |
The distribution and molecular weights of cellular proteins in soluble and membrane-associated locations were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Coomassie blue staining of leaf (Digitaria sanguinalis L. Scop.) extracts and isolated cell extracts. Leaf polypeptides also were pul... |
The stepwise synthesis and assembly of photosynthetic membrane components in the y-1 mutant of Chlamydomonas reinhardi have been previously demonstrated (Ohad 1975 In Membrane Biogenesis, Mitochondria, Chloroplasts and Bacteria, Plenum, pp 279-350). This experimental system was used here in order to investigate the pro... |
The presence of a nonspecific acid phosphatase which had high activity with 3-phosphoglycerate as substrate has recently been reported in Spinacia oleracea L. chloroplasts (Mulligan, Tolbert 1980 Plant Physiol 66: 1169-1173). The subcellular localization of this activity has been reinvestigated by differential centrifu... |
Phosphofructokinase has been partially purified from spinach (Spinacia oleracea) chloroplasts and studied from the standpoint of light/dark regulation. At concentrations reported to occur physiologically, NADPH effected a sharp inhibition of the enzyme by: (a) lowering its affinity (increasing the apparent K(m)) for bo... |
Protein bodies were prepared from the cotyledons of pumpkin (Cucurbita sp.) seeds by employing a nonaqueous isolation method. Both light micrographic examination and the marker enzyme assays have shown that the isolated protein bodies were intact and contamination with other cell organelles or cytoplasmic components wa... |
A NADPH-dependent reductase activity, capable of converting (+)-dihydroquercetin (2,3-trans) to its 3,4-diol (a leucocyanidin), has been demonstrated in crude, soluble protein extracts derived from cell suspension cultures of Douglas fir (Pseudotsuga menziessi). Neither NADH nor ascorbate substituted as the H-donor. Qu... |
An alkaline fructose 1,6-bisphosphatase activity associated with soybean (Glycine max cv Beeson) chloroplasts appears to be membrane-bound. The pH optimum of the membrane-associated activity corresponds to that found for activity associated with the stroma. Illumination of washed thylakoids results in an increase in al... |
A Mg(2+)-dependent, alkaline phosphatase has been isolated from mature pollen of Lilium longiflorum Thunb., cv. Ace and partially purified. It hydrolyzes 1l- and 1d-myo-inositol 1-phosphate, myo-inositol 2-phosphate, and beta-glycerophosphate at rates decreasing in the order named. The affinity of the enzyme for 1l- an... |
Cell suspension cultures were established from the callus proliferation of leaf explants of 10- to 12-day-old seedlings of the peanut (Arachis hypogaea L. var. TMV-3). The cells could be cultivated in both agitated and still media, the latter promoting more of chlorophyll (Chl) synthesis. High Chl content (210-240 micr... |
Rabbit antiserum was raised against ferredoxin-dependent glutamate synthase (EC 1.4.7.1) purified from green leaves of Oryza sativa L. cv Delta. Ferredoxin-dependent glutamate synthase, detected in green leaf, etiolated leaf, and root tissues cross-reacted completely with the antiferredoxin glutamate synthase immunoglo... |
The effects of 1 millimolar glyphosate (N-[phosphonomethyl]glycine) upon the activities of enzymes of aromatic amino acid biosynthesis, partially purified by ion-exchange chromatography from mung bean seedings (Vigna radiata [L.] Wilczek), were examined. Multiple isozyme species of shikimate dehydrogenase, chorismate m... |
Nitrate reductase was localized in mycelial cells of Neurospora crassa by immunohistochemical labeling with ferritin. The enzyme is found in the cell wall-plasmalemma region and in the tonoplast membranes. |
The ultrastructural changes occurring in the scutellar epithelium cells of rice seeds have been studied during germination and early seedling growth. During this time, several prominent structural changes occur, including (a) formation, development, and proliferation of organelles such as mitochondria, rough endoplasmi... |
The site of synthesis of the plastid membrane-located enzyme, protochlorophyllide reductase, has been determined. Plastid ribosome-deficient and normal rye (Secale cereale L., cv Rheidol) plants were grown in darkness at 33 degrees C and 22 degrees C, respectively. Extracts from these plants were analyzed for the level... |
Chloroplasts isolated from seedlings of a virescens mutant of barley (Hordeum vulgare L cv Gateway) grown for 6 days under continuous illumination had lower levels of photosystem II activities on a chlorophyll basis than wild-type seedlings. After 8 days, however, the photosystem II rates of the mutant and wild-type we... |
Photoconversion of protochlorophyllide in etiolated leaves of Avena sativa L., var. Pennal or Peniarth and Phaseolus vulgare L., var. ;The Prince' results in the sequential appearance of spectrally distinct chlorophyllide complexes (Chlide 678, 684, and 672). This paper reports on the generation of similar forms in vit... |
Indoleacetic acid induces senescence in isolated carnation (Dianthus caryophyllus, cv. White Sim) petals, increasing the duration and amount of ethylene production. This effect is inhibited by Actinomycin D, an inhibitor of RNA synthesis, and cycloheximide, a translational inhibitor of protein synthesis. The ability of... |
Sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of the starchy endosperm protein of rice (Oryza sativa L. Japonica cv Koshihikari) during seed development confirmed that storage protein begins to accumulate about 5 days after flowering. Two polypeptide groups, 22 to 23 and 37 to 39 kilodaltons, the c... |
Improvements are described in the preparation and in vitro conditions of an intact pea (Pisum sativum Progress No. 9) chloroplast system which provides high efficiency for translation of endogenous messenger RNA, using light as an energy source. High rates result in the incorporation into protein of up to 100 nanomoles... |
When abraded oat (Avena sativa L. cv Victory) leaf segments are floated on KCl solution, white light causes acidification of the solution external to leaf tissue. The presence of mannitol amplifies the light-induced proton secretion. Mature leaves as well as young ones acidify the medium in light, while senescing leave... |
Coniferyl alcohol is the primary substrate for peroxidase-mediated lignification, a process which depends on the generation of H(2)O(2) by NADH oxidation. We measured the concentrations of various phenols (synthetic and natural) at which maximal enhancement of NADH oxidation occurs. Coniferyl alcohol was found to stimu... |
The effect of increasing assay medium sorbitol concentration from 0.33 to 1.0 molar on the photosynthetic reactions of intact and broken spinach (Spinacia oleracea L. var. Long Standing Bloomsdale) chloroplasts was investigated by monitoring O(2) evolution supported by the addition of glyceric acid 3-phosphate (PGA), o... |
The secretion of alpha-amylase from single isolated (Hordeum vulgare L. cv Himalaya) aleurone layers was studied in an automated flow-through apparatus. The apparatus, consisting of a modified sample analyzer linked to a chart recorder, automatically samples the flow-through medium at 1 minute intervals and assays for ... |
NAD malic enzyme can exist in dimer, tetramer, or octamer form. Freshly prepared enzyme from Solanum tuberosum var. Chieftan exists predominantly as the octamer and during storage is progressively converted into lower molecular weight forms. High ionic strength favors dimer formation, whereas high concentrations of mal... |
The structure of canavalin, a jack bean (Canavalis ensiformis) protein homologous to phaseolin, the major seed storage protein of Phaseolus vulgaris, has been investigated by x-ray crystallography and found to be a hexamer composed of three identical pairs of similar but nonidentical subunits related by a perfect 3-fol... |
Intact peroxisomes were prepared from green leaves of a number of C(3) species, both monocots and dicots. A protoplast extract from which chloroplasts have been removed by a 1-minute 10,000g centrifugation was applied to a step gradient of 5, 15, 30, and 45% Percoll containing 0.5 molar sucrose, 0.1% BSA, and 25 millim... |
Guard cell pairs were dissected from freeze-dried leaves of plants representing 15 families, including monocots, dicots, and pteridophytes. All three major photosynthetic carbon pathways (C(2), C(4), and Crassulacean acid metabolism) were represented. These individual guard cell pairs were assayed quantitatively for ri... |
Immature seeds of Phaseolus vulgaris removed from the pod at 32 days of development do not germinate unless first subjected to a desiccation treatment. This change from development to germination caused by premature drying is mirrored in the pattern of protein synthesis by the axes. Rehydrated axes from 32-day-develope... |
The cleavage of D(s)-isocitrate catalyzed by isocitrate lyase from Linum usitatissimum results in the ordered release of succinate and glyoxylate. The glyoxylate analog 3-bromopyruvate irreversibly inactivates the flax enzyme in a process exhibiting saturation kinetics and protection by glyoxylate or isocitrate or the ... |
The effect of cyanide and rotenone on malate (pH 6.8), malate plus glutamate (pH 7.8), citrate, alpha-ketoglutarate, and succinate oxidation by cauliflower (Brassica oleracea L.) bud, sweet potato (Ipomoea batatis L.) tuber, and spinach (Spinacia oleracea and Kalanchoë daigremontiana leaf mitochondria was investigated.... |
Studies of isolated intact spinach (Spinacia oleracea L.) chloroplasts reveal that most of the available sulfhydryl groups are associated with stromal protein as opposed to a thylakoid membrane fraction under non-denaturing conditions. Increases in sulfhydryl content of approximately 50% occurred with illumination and ... |
Developing chloroplasts of Cucumis sativus L., cv Beit Alpha which were incubated with either Mg-protoporphyrin IX or Mg-protoporphyrin IX monomethyl ester in darkness produced a partially phototransformable protochlorophyllide species that was tentatively identified as Mg-2,4-divinyl pheoporphyrin a(5). S-Adenosylmeth... |
Nitrate or ammonium was added to soybean (Glycine max L. Merrill cv Corsoy) plants grown in plastic pouches 10 days after nodules first appeared. By the third day of treatment with 10 millimolar nitrate, nitrogenase specific activity (per unit nodule weight) had decreased to 15% to 25% of that of untreated plants. Long... |
A light-dependent reversible grana stacking-unstacking process, paralleled by a reorganization of thylakoid components, has been noticed in greening etiolated bean (Phaseolus vulgaris, var. red kidney) leaves upon transfer to darkness. The reorganization, based on biochemical and biophysical criteria, involves mainly t... |
Intact chloroplasts from spinach (Spinacia oleracea L., hybrid 424) readily incorporate [(14)C]glycerol-3-phosphate and [(14)C]acetate into diacylglycerol, monoacylglycerol, diacylglycrol, free fatty acids (only when acetate is the precursor), phosphatidic acid, phosphatidylcholine, and most notably phosphatidylglycero... |
A manganese-containing superoxide dismutase (EC 1.15.1.1) was fully characterized from leaves of the higher plant Pisum sativum L., var. Lincoln. The amino acid composition determined for the enzyme was compared with that of a wide spectrum of superoxide dismutases and found to have a highest degree of homology with th... |
Rates of respiratory CO(2) loss and nitrogenase activities of H(2) uptake-negative mutant strains and H(2) uptake-positive revertant strains of Rhizobium japonicum have been investigated. Two-dimensional gel protein patterns of bacteroids formed by inoculation of soybeans (Glycine max L.) with these two strains show th... |
Propargylglycine, vinylglycine, and cysteine each cause irreversible inactivations of cystathionine gamma-synthase (and, in parallel, of O-phosphohomoserine sulfhydrylase) activities in crude extracts of Lemna paucicostata. Inactivation by propargylglycine or vinylglycine is completely prevented by 40 millimolar O-phos... |
A protein, extracted from Katahdin potato (Solanum tuberosum L. cv ;Katahdin') tubers and purified by ion exchange chromatography and gel filtration, agglutinates avirulent strains of the bacterial wilt pathogen, Pseudomonas solanacearum, but only weakly agglutinates virulent strains. The agglutinin has very low hemagg... |
At least four different proteinases are present in senescing apple leaves (Malus domestica Borkh. cv. Golden Delicious) as determined by their pH optima, substrate specificity, and their reactivity to proteinase inhibitors. An enzyme active at pH 4.5 to 5.0 appears to be a sulfhydryl-dependent (iodoacetamide and phenyl... |
After preparation on self-generated Percoll gradients, avocado (Persea americana Mill, var. Fuerte and Hass) mitochondria retain a high proportion of cyanide-insensitive respiration, especially with alpha-ketoglutarate and malate as substrates. Whereas alpha-ketoglutarate oxidation remains unchanged, the rate of malate... |
Cotyledons of developing Phaseolus vulgaris L. cv Greensleeves seeds were labeled for 2 to 3 hours with (3)H-amino acids, and newly synthesized phytohemagglutinin (PHA) was isolated by affinity chromatography with thyroglobulin-Sepharose. The presence of 1% Tween in the homogenate increased the yield of radioactive PHA... |
The effects of aminoacetonitrile (a competitive inhibitor of glycine oxidation) on net photosynthesis, glycolate pathway intermediates, and ribulose-1,5-bisphosphate (RuBP) levels have been investigated at different O(2) and CO(2) concentrations with soybean (Glycine max)[L] Merr. cv Pioneer 1677) leaf discs floated on... |
The ATP phosphohydrolase (ATPase) activity of a corn (Zea mays L., WF9 x Mo17) root plasma membrane fraction was enriched almost 2-fold by selective extraction with 0.1% (w/v) deoxycholate. The detergent treatment solubilized about 30% of the total membrane protein and some ATP hydrolyzing activity that was not K(+)-st... |
Depodding soybean (Glycine max [L] Merr. cv Wye) plants results in an apparent inhibition of senescence as indicated by leaf chlorophyll and soluble protein retention. However, leaf photosynthesis and ribulose bisphosphate carboxylase (Rubisco) levels begin to decline earlier in depodded than in control, podded plants.... |
Guard cells and three other cell types from Vicia faba L. ;Longpod' leaflets were assayed for enzymes that catalyze one step in each of five major carbon pathways in green plants: the photosynthetic carbon reduction pathway (ribulose-bisphosphate carboxylase, EC 4.1.1.39), the photosynthetic carbon oxidation pathway (h... |
Changes in activities of photosynthetic enzymes and photochemical processes were followed with aging of vegetative and flag leaves of wheat (Triticum aestivum L. cv Roy). Activities of stromal enzymes began to decline prior to photochemical activities. In general, total soluble protein and the activities of ribulose-1,... |
The gibberellic acid (GA(3))-induced alpha-amylases from the aleurone layers of Himalaya barley (Hordeum vulgare L. cv Himalaya) have been purified by cycloheptaamylose-Sepharose affinity chromatography and fractionated by DEAE-cellulose chromatography. Four fractions (alpha-amylases 1-4) were obtained which fell into ... |
Extracts of immature kernels of Zea mays L. catalyzed the synthesis of indol-3-yl-acetyl-myo-inositol arabinoside from indol-3-yl-acetyl-myo-inositol and UDP-[U-(14)C]xylose. The product contained radioactivity which upon hydrolysis with trifluoroacetic acid cochromatographed with arabinose and not xylose. The amount o... |
Roots of sunflower plants (Helianthus annuus L. var. Mammoth Russian) subjected to L12:D12, L18:D6, and L12:D12 followed by continuous light all display rhythms of about 12 hours for glutamine synthetase (GS) activity (transferase reaction) with one peak in the ;light phase' and one in the ;dark phase.' Root energy cha... |
The influence of polyploidization on ribulose-1,5-bisphosphate carboxylase (RuBPCase), buffer-soluble protein (BSP), chlorophyll (Chl), and DNA was examined in fully expanded leaves of isogenic diploid-tetraploid (DDC 2X-4X) and tetraploid-octoploid (IC 4X-8X) sets of alfalfa (Medicago sativa L.). The concentration of ... |
Host plant glutamine synthetase (GS) has been purified 100-fold from N(2)-fixing alfalfa (Medicago sativa L.) nodules by a new procedure involving preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) as a final step. An SDS-polypeptide fraction corresponding to plant GS was identified and co... |
The oat (Avena sativa L.) seed globulin was found to be synthesized in vitro as 60,000 to 64,000 dalton precursors. In vivo protein labeling yielded polypeptides of 58,000 to 62,000 daltons, suggesting cleavage of signal sequences from the precursors. Further cleavage is apparently required to separate the alpha and be... |
Nitrate reductase was localized in mycelial cells of Neurospora crassa by immunohistochemical labeling with ferritin. The enzyme is found in the cell wall-plasmalemma region and in the tonoplast membranes. |
The light-harvesting chlorophyll protein system of the alga Chlamydobotrys stellata consists of an as yet uncharacterized algal chlorophyll a-protein, called LHCPa, and a common photosystem II-related chlorophyll a/b-protein, called LHCPb (Brandt, Kaiser-Jarry, Wiessner 1982 Biochim Biophys Acta 679: 404-409). For furt... |
Tomatoes (Lycopersicon esculentum L.) contained a high level of beta-galactosidase activity which was due to three forms of the enzyme. During tomato ripening, the sum of their activities remained relatively constant, but the levels of the individual forms of beta-galactosidase changed markedly. The three enzymes were ... |
Nitrate reductase-deficient barley (Hordeum vulgare L.) mutants were assayed for the presence of a functional molybdenum cofactor determined from the activity of the molybdoenzyme, xanthine dehydrogenase, and for nitrate reductase-associated activities. Rocket immunoelectrophoresis was used to detect nitrate reductase ... |
A pyrophosphate-dependent phosphofructokinase (PPi-PFK) activity is detectable in extracts of a wide variety of primitive and advanced plants, the Charalean algae, and in the photosynthetic bacterium, Rhodospirillum rubrum. Angiosperms with extractable PPi-PFK activities 4- to 70-fold higher than the respective ATP-PFK... |
A family of immunologically identical glycoproteins with apparent molecular weights of approximately 40,000 are among the major tuber proteins of potato (Solanum tuberosum L.). These proteins, as purified by ion-exchange and affinity chromatography, have been given the trivial name ;patatin.' To determine if patatin ca... |
In Poterioochromonas malhamensis Peterfi (syn. Ochromonas malhamensis Pringsheim) osmotically induced shrinkage is reversed by an accumulation of isofloridoside. Addition of Ca(2+) ions to homogenates from standard volume cells initiates an enzyme system for the activation of isofloridoside-phosphate synthase. This pro... |
alpha-Amylase activity increased in attached cotyledons of germinated Vigna mungo seeds until the 5th day after imbibition and decreased thereafter, whereas in detached and incubated cotyledons the activity continuously increased and, at the 6th day, reached the value more than three times that of the maximum activity ... |
Reduced glutathione, but not mercaptoethanol or dithiothreitol, inhibits phosphoenolpyruvate carboxylase (PEPC) in desalted leaf extracts from Sedum praealtum D.C. The inhibition is more evident at low pH values (< 7.2) and becomes increasingly smaller at higher pH. In the presence of the inhibitor, the hyperbolic rate... |
A new indole oxygenase from the leaves of Tecoma stans was isolated and purified to homogenity. The purified enzyme system catalyzes the conversion of indole to anthranilic acid. It is optimally active at pH 5.2 and 30 degrees C. Two moles of oxygen are consumed and one mole of anthranilic acid is formed for every mole... |
NADH:nitrate reductase (EC 1.6.6.1) was isolated and purified from the green cotyledons of 5-day-old squash seedlings (Cucurbita maxima L.). The 10-hour purification procedure consisted of two steps: direct application of crude enzyme to blue Sepharose and specific elution with NADH followed by direct application of th... |
A mechanical isolation procedure was developed to study the respiratory properties of mitochondria from the mesophyll and bundle sheath tissue of Panicum miliaceum, a NAD-malic enzyme C(4) plant. A mesophyll fraction and a bundle sheath fraction were obtained from young leaves by differential mechanical treatment. The ... |
Ribonucleic acid and protein synthesis in developing wheat kernels have been studied through in vivo labeling of wheat heads in culture. In INIA 66R wheat labeled with [5-(3)H]uridine for 24-hour periods between 9 and 33 days after flowering, the total rate of RNA accumulation in endosperm/testa pericarp tissues was hi... |
It was shown previously that when peas (Pisum sativum L.) are grown with suboptimal sulfur supply the level of legumin (the more S-rich of the two major seed storage proteins) in the mature seed is selectively reduced (Randall, Thomson, Schroeder, 1979 Aust J Plant Physiol 6: 11-24). This paper reports a study of the c... |
The effect of varied anaerobic atmospheres on the metabolism of sweet potato (Ipomoea batatas [L.] Lam.) roots was studied. The internal gas atmospheres of storage roots changed rapidly when the roots were submerged under water. O(2) and N(2) gases disappeared quickly and were replaced by CO(2). There were no appreciab... |
In air largely freed from CO(2), senescence of isolated oat (Avena sativa cv Victory) seedling leaves is no longer prevented by white light; instead, the leaves lose both chlorophyll and protein as rapidly as in the dark. Senescence in light is also accelerated in pure O(2), but it is greatly delayed in N(2); 100% N(2)... |
Cotyledons of maturing Phaseolus vulgaris seeds contain three isozymes of alpha-mannosidase which can be separated by isoelectrofocusing. They have isoelectric points of 5.3, 5.8, and 6.5 to 7.5 and were named I, II, and III in order of ascending pI. All three had an acid pH optimum (4.5) and required Zn(2+) for maxima... |
The formation of multiple forms of amylases in germinating rice (Oryza sativa L. cv Kimmaze) grains was examined by means of isoelectric focusing, cross-immunoelectrophoresis, and rocket-line immunoelectrophoresis followed by a reaction of enzymic characterization by using beta-limit dextrin or starch as substrate. The... |
The pattern of protein synthesis in roots of 3-day-old maize seedlings (Zea mays L.) is rapidly and dramatically altered when the incubation temperature is raised from 25 to 40 degrees C. One-dimensional sodium dodecyl sulfate gels reveal that although synthesis of the proteins observed at 25 degrees C continues at 40 ... |
The specific measurement of alpha-amylase activity in crude plant extracts is difficult because of the presence of beta-amylases which directly interfere with most assay methods. Methods compared in this study include heat treatment at 70 degrees C for 20 min, HgCl(2) treatment, and the use of the alpha-amylase specifi... |
Johnsongrass (Sorghum halepense (L.) Pers.) is sensitive to methanearsonate, foliar application resulting in a topkill. Investigation of the pattern of photosynthesis by radioautography revealed an accumulation of malate in methanearsonate-treated leaves. Accumulation of malate was attributed to an inhibition of NADP(+... |
During initial exposure to 40 nanomolar propargylglycine (PAG), Lemna paucicostata colonies undergo abnormal fragmentation and a lag in frond emergence, most severe at 24 to 48 hours. Thereafter, frond emergence resumes and the frond/colony ratio rises. Such ;adapted' plants withstand subculture into the same concentra... |
Purified aconitase, an iron-sulfur protein, from either beef heart mitochondria or pig heart can be activated fully by light when combined with washed thylakoid membranes from pea (Pisum sativum L.) chloroplasts. The light activation of the enzyme does not require any other additive or cofactor and is sensitive to 3-(3... |
Treatment of hypocotyl sections or cell suspension cultures of dwarf French bean (Phaseolus vulgaris L.) with an abiotic elicitor (denatured ribonuclease A) resulted in increased extractable activity of the enzyme l-phenylalanine ammonia-lyase. This induction could be transmitted from treated cells through a dialysis m... |
Chlamydomonas reinhardii cells, growing photoautotrophically under air, excreted to the culture medium much higher amounts of NO(2) (-) and NH(4) (+) under blue than under red light. Under similar conditions, but with NO(2) (-) as the only nitrogen source, the cells consumed NO(2) (-) and excreted NH(4) (+) at similar ... |
The enzyme 3'-AMP nucleotidase was purified 2,500- to 5,000-fold from extracts of an acetone powder of wheat (Triticum aestivum) embryonic axes germinated for 40 hours. Sodium dodecyl sulfate acrylamide gel electrophoresis and chromatography on Biogel-P100 indicate that the enzyme is monomeric with a molecular weight o... |
A membrane fraction enriched with a magnesium-dependent, monovalent cation-stimulated ATPase was isolated from red beet (Beta vulgaris L.) storage roots by a combination of differential centrifugation, extraction with KI, and sucrose density gradient centrifugation. This fraction was distinct from endoplasmic reticulum... |
The galactosylation steps in the biosynthesis of galactolipids involve two different enzymes; a UDP-Gal:diacylglycerol galactosyltransferase and a galactolipid:galactolipid galactosyltransferase. Previous localization studies have shown that in spinach these enzymes are located in the chloroplast envelope. Our results ... |
Upon exposure to 2 degrees C day/night (D/N), leaves of Solanum commersonii (Sc) began acclimating on the 4th day from a -5 degrees C (killing temperature) hardy level to -12 degrees C by the 15th day. Leaves of S. tuberosum L. (St) cv ;Red Pontiac' typically failed to acclimate and were always killed at -3 degrees C. ... |
Nodule senescence was induced in intact soybean [Glycine max. (L.) Merr., cv Woodworth] plants by an 8-day dark treatment. Dark-induced senescence resulted in the complete loss of acetylene reduction activity, a 67% loss of total soluble protein, and an almost complete loss in total leghemoglobin of nodule extracts. Is... |
The effects of the photosystem II herbicides diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) and atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) on the photosynthetic membranes of a cyanobacterium, Aphanocapsa 6308, were compared to the effects on a higher plant, Spinacia oleracea. The inhibition of photo... |
The developmental profile of the glyoxysomes and their component enzymes catalase, malate synthase, and isocitrate lyase were compared in the scutellum of two maize (Zea mays) lines, Illinois High Oil (IHO, approximately 20% lipid content) and Illinois Low Oil (ILO, less than 0.5% lipid content). The microbodies partic... |
Two enzymes from soybean (Glycine max L. Merr. cv Harosoy 63) cotyledons released elicitor-active carbohydrates from cell walls of the phytopathogenic fungus Phytophthora megasperma f.sp. glycinea. They were identified as isoenzymes of beta-1,3-endoglucanase (EC 3.2.1.39) with isoelectric points of pH 8.7 and 10.5. The... |
The major cytokinin binding protein of wheat germ (CBP) was extensively purified employing chromatography on Cibacron F3GA-Sepharose CL6B and concanavalin A-agarose as key purification steps. The major polypeptides present in the purified CBP preparations have molecular weights of 60,000 +/- 4,000, 42,000 +/- 3,000, an... |
A protein kinase was extensively purified to near-homogeneity from wheat germ by a procedure involving affinity chromatography on casein-Sepharose 4B, gel filtration, and repeated chromatography on carboxymethyl-Sepharose CL-6B. The protein kinase preparations have the highest specific activities (up to 656 nanomoles p... |
When intact mesophyll chloroplasts of Zea mays var Kelvedon Glory were illuminated, activation of NADP-malate dehydrogenase occurred. Activity declined rapidly on darkening. Light activation of the enzyme was very much greater in the presence of pyruvate ( approximately 10- to 20-fold) than with the electron acceptors ... |
When a plasma membrane-enriched fraction isolated from red beet (Beta vulgaris L.) was incubated in the presence of 40 micromolar [gamma-(32)P] ATP, 40 micromolar MgSO(4) at pH 6.5, a rapidly turning over phosphorylated protein was formed. Phosphorylation of the protein was substrate-specific for ATP, sensitive to diet... |
To compare oat (Avena sativa L. cv Froker) aleurone protein bodies with those of the starchy endosperm, methods were developed to isolate these tissues from mature seeds. Aleurone protoplasts were prepared by enzymic digestion and filtration of groat (caryopsis) slices, and starchy endosperm tissue was separated from t... |
The indolizidine alkaloid, swainsonine, was previously shown to be a potent inhibitor of lysosomal and jack bean alpha-mannosidase (Dorling, Huxtable, Colegate 1980 Biochem J 191: 649-651). We examined the effects of various concentrations of this alkaloid on a number of commercially available glycosidases and found sw... |
Nitrate reductase from wheat (Triticum aestivum L. cv Bindawarra) leaves is inactivated by pretreatment with NADH, in the absence of nitrate, a 50% loss of activity occurring in 30 minutes at 25 degrees C with 10 micromolar NADH. Nitrate (50 micromolar) prevented inactivation by 10 micromolar NADH while cyanide (1 micr... |
The nitrogen content of cell wall preparations from normal tomato (cv Ailsa Craig) fruit remained constant during ripening, whereas salt-soluble protein increased throughout this process. Tomato polygalacturonase released about twice as much protein from the preparations as salts did, with a maximum at the orange stage... |
Phosphoglycerate dehydrogenase (EC 1.1.1.95), an enzyme believed to be involved in the synthesis of serine, an intermediate in ureide biosynthesis, has been purified about 200-fold from nodules of soybean (Glycine max L. Merr. cv Amsoy 71). The reaction was reversible and exhibited a strong pH dependence with optima of... |
A fourth molecular from of alpha-galactosidase, designated L(IV), an alkaline alpha-galactosidase, was isolated from leaves of Cucurbita pepo and purified 165-fold. It was active over a narrow pH range with optimal hydrolysis of p-nitrophenyl-alpha-d-galactoside and stachyose at pH 7.5. The rate of stachyose hydrolysis... |
Quiescent cottonseeds (Gossypium hirsutum L.) were fractionated non-aqueously to protein bodies and nonparticulate cytoplasm for analyses of sugar contents. Nonparticulate cytoplasm was more than 3-fold richer in total free sugars than were protein bodies, but based on the content of cytoplasm in each fraction, sugars ... |
The N,N'-dicyclohexylcarbodiimide (DCCD)-sensitive ATPase of pea (Pisum sativum L.) cotyledon mitochondria was solubilized from submitochondrial particle membranes with sodium cholate and ammonium sulfate. Ammonium sulfate precipitation of the enzyme resulted in an increase in specific activity. At between 38% and 45% ... |
Alcohol dehydrogenase (ADH) was measured in the various organs of rice seedlings (Oryza sativa) growing in air. In extracts from ungerminated seeds, the ADH is stable, but in extracts from seedlings more than 2 days old the enzyme initially present loses activity in a time- and temperature-dependent fashion, due to the... |
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