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You searched for: Journal Plant physiology Remove constraint Journal: Plant physiology Publication Year 1997 Remove constraint Publication Year: 1997 Subject term dose response Remove constraint Subject term: dose response
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1. Accelerated early growth of rice at elevated CO2. Is it related to developmental changes in the shoot apex?

Author:
Jitla, D.S.; Rogers, G.S.; Seneweera, S.P.; Basra, A.S.; Oldfield, R.J.; Conroy, J.P.
Source:
Plant physiology 1997 v.115 no.1 pp. 15-22
ISSN:
0032-0889
Subject:
plant development; buds; diameter; dose response; carbon dioxide; Oryza sativa; developmental stages; internodes; crop yield; length; tillers; leaves
Abstract:
... The influence of elevated CO2 on the development of the shoot apex and on subsequent vegetative growth and grain yield investigated using rice (Oryza sativa L. cv Jarrah) grown in flooded soil at either 350 or 700 microliter CO2 L-1. At 8 d after planting (DAP), elevated CO2 increased the height and diameter of the apical dome and lengths of leaf primordia and tiller buds but had no effect on thei ...

2. Al partitioning patterns and root growth as related to Al sensitivity and Al tolerance in wheat

Author:
Samuels, T.D.; Kucukakyuz, K.; Rincon-Zachary, M.
Source:
Plant physiology 1997 v.113 no.2 pp. 527-534
ISSN:
0032-0889
Subject:
Triticum aestivum; roots; aluminum; quantitative analysis; dose response; phytotoxicity; cultivars; translocation (plant physiology); biological resistance
Abstract:
... Studies of Al partitioning and accumulation and of the effect of Al on the growth of intact wheat (Triticum aestivum L.) roots of cultivars that show differential Al sensitivity were conducted. The effects of various Al concentrations on root growth and Al accumulation inthe tissue were followed for 24 h. At low external Al concentrations, Al accumulation in the root tips was low and root growth w ...

3. Antagonistic but complementary actions of phytochromes A and B allow optimum seedling de-etiolation

Author:
Smith, H.; Xu, Y.; Quail, P.H.
Source:
Plant physiology 1997 v.114 no.2 pp. 637-641
ISSN:
0032-0889
Subject:
Arabidopsis thaliana; seedlings; hypocotyls; phytochrome; dose response; red light; far-red light; genetic variation; genotype; etiolation
Abstract:
... Using dichromatic radiation, we show that the actions of phytochromes A and B (phyA and phyB) in Arabidopsis thaliana are antagonistic in mediating red and far-red radiation effects on seedling de-etiolation and yet act in a complementary manner to regulate de-etiolation, irrespective of spectral composition. At low phytochrome photoequilibria inhibition of hypocotyl extension was strong, because ...

4. Auxin-induced epinasty of tobacco leaf tissues. A nonethylene-mediated response

Author:
Keller, C.P.; Van Volkenburgh, E.
Source:
Plant physiology 1997 v.113 no.2 pp. 603-610
ISSN:
0032-0889
Subject:
Nicotiana tabacum; leaves; cell growth; epinasty; dose response; acetic acid; ethylene; biosynthesis; naphthaleneacetic acid; aminooxyacetic acid; indole acetic acid
Abstract:
... Interveinal strips (10 x 1.5 mm) excised from growing tobacco (Nicotiana tabacum L. cv Xanthi) leaves curled >300 degrees when incubated for 20 h in 5 to 500 micromolar alpha-naphthalene acetic acid or 50 to 500 micromolar indole-3-acetic acid. Epinasty was not induced without auxin or by the auxin analog beta-naphthalene acetic acid, and less substantial epinasty was induced in midrib and vein se ...

5. Blue-light-induced shrinking of protoplasts from maize coleoptiles and its relationship to coleoptile growth

Author:
Wang, X.; Iino, M.
Source:
Plant physiology 1997 v.114 no.3 pp. 1009-1020
ISSN:
0032-0889
Subject:
protoplasts; coleoptiles; Zea mays; dose response; volume; blue light; red light; photoreceptors
Abstract:
... Protoplasts isolated from red-light-grown maize (Zea mays L.) coleoptiles shrank transiently upon brief exposure (e.g. 30 s) to blue light under background irradiation with red light. The maximal volume reduction (about 4% at a saturating fluence) occurred about 5 min after blue-light stimulation. The response was prevented by the anion-channel blocker 5-nitro-2-(3-phenylpropylamino)-benzoic acid. ...

6. Ca2+-activated anion channels and membrane depolarizations induced by blue light and cold in Arabidopsis seedlings

Author:
Lewis, B.D.; Karlin-Neumann, G.; Davis, R.W.; Spalding, E.P.
Source:
Plant physiology 1997 v.114 no.4 pp. 1327-1334
ISSN:
0032-0889
Subject:
Arabidopsis thaliana; seedlings; hypocotyls; ion transport; cytoplasm; calcium; dose response; blue light; cold stress; luminescence; plasma membrane
Abstract:
... The activation of an anion channel in the plasma membrane of Arabidopsis thaliana hypocotyls by blue light (BL) is believed to be a signal-transducing event leading to growth inhibition. Here we report that the open probability of this particular anion channel depends on cytoplasmic Ca2+ ([Ca2+]cyt) within the concentration range of 1 to 10 micrometers, raising the possibility that BL activates th ...
PubMed:
9276950
PubMed Central:
PMC158425

7. Cellulose and callose biosynthesis in higher plants. 1. Solubilization and separation of (1 leads to 3)- and (1 leads to 4)-beta-glucan synthase activities from mung bean

Author:
Kudlicka, K.; Brown, R.M. Jr.
Source:
Plant physiology 1997 v.115 no.2 pp. 643-656
ISSN:
0032-0889
Subject:
digitonin; hexosyltransferases; polypeptides; biosynthesis; dose response; callose; Vigna radiata; cellulose; cell membranes; solubility; electrophoresis; beta-glucans; enzyme activity; protein composition
Abstract:
... (1 leads to 3) and (1 leads to 4)-beta-glucan synthase activities from higher plants have been physically separated by gel electrophoresis in nondenaturing conditions. The two glucan synthases show different mobilities in native polyacrylamide gels. Further separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a different polypeptide composition in these synthases. Three ...

8. Differential ammonia-elicited changes of cytosolic pH in root hair cells of rice and maize as monitored by 2',7'-bis-(2-carboxyethyl)-5 (and -6)-carboxyfluorescein-fluorescence ratio

Author:
Kosegarten, H.; Grolig, F.; Wieneke, J.; Wilson, G.; Hoffmann, B.
Source:
Plant physiology 1997 v.113 no.2 pp. 451-461
ISSN:
0032-0889
Subject:
ammonia; Zea mays; dose response; fluorescein; chemical reactions; glutamine; Oryza sativa; fluorescence; glutamates; nutrient uptake; cytosol; biochemical pathways; root hairs; ligases; pH; alkalinity; measurement; enzyme activity; glutamic acid
Abstract:
... Intact hair cells of young rice (Oryza sativa L.) and maize roots (Zea mays L.), grown without external nitrogen, were specifically loaded with 2',7'-bis-(2-carboxyethyl)-5 (and -6)-carboxyfluorescein acetoxymethyl ester to monitor fluorescence ratio cytosolic pH changes in response to external ammonia (NH4+/NH3) application. In neutral media, cytosolic pH of root hairs was 7.15 +/- 0.13 (O. sativ ...

9. Differential induction of lipoxygenase isoforms in wheat upon treatment with rust fungus elicitor, chitin oligosaccharides, chitosan, and methyl jasmonate

Author:
Bohland, C.; Balkenhohl, T.; Loers, G.; Feussner, I.; Grambow, H.J.
Source:
Plant physiology 1997 v.114 no.2 pp. 679-685
ISSN:
0032-0889
Subject:
protein synthesis; dose response; chitosan; seedlings; jasmonic acid; linoleate 13S-lipoxygenase; Puccinia graminis; Triticum aestivum; leaves; plant pathogenic fungi; oligosaccharides; chitin; enzyme activity; isozymes; protein composition
Abstract:
... A glycopeptide elicitor prepared from germ tubes of the rust fungus Puccinia graminis Pers. f. sp. tritici Erikss. & Henn (Pgt),as well as chitin oligosaccharides, chitosan, and methyl jasmonate (MJ) stimulated lipoxygenase (LOX) activity (E.C. 1.13.11.12) in wheat (Triticum aestivum) leaves. Immunoblot analysis using anti-LOX antibodies revealed the induction of 92- and 103-kD LOX species after P ...

10. Dissecting the diphenylene lodonium-sensitive NAD(P)H: quinone oxidoreductase of zucchini plasma membrane

Author:
Trost, P.; Foscarini, S.; Preger, V.; Bonora, P.; Vitale, L.; Pupillo, P.
Source:
Plant physiology 1997 v.114 no.2 pp. 737-746
ISSN:
0032-0889
Subject:
dose response; hypocotyls; NADP (coenzyme); oxidoreductases; Cucurbita pepo; enzyme inhibitors; binding sites; etiolation; plasma membrane; enzyme activity; protein composition
Abstract:
... Quinone oxidoreductase activities dependent on pyridine nucleotides are associated with the plasma membrane (PM) in zucchini (Cucurbita pepo L.) hypocotyls. In the presence of NADPH, lipophilic ubiquinone homologs with up to three isoprenoid units were reduced by intact PM vesicles with a Km of 2 to 7 micromolars. Affinities for both NADPH and NADH were similar (Km of 62 and 51 micromolars, respec ...

11. Diurnal fluctuations in ethylene formation in Chenopodium rubrum

Author:
Machackova, I.; Chauvaux, N.; Dewitte, W.; Onckelen, H. van.
Source:
Plant physiology 1997 v.113 no.3 pp. 981-985
ISSN:
0032-0889
Subject:
1-aminocyclopropane-1-carboxylic acid; Chenopodium rubrum; seedlings; light; dose response; ethylene; biosynthesis; diurnal variation; photoperiod; flowering; shoots; roots; quantitative analysis; malonic acid; oxidoreductases; enzyme activity; chemical constituents of plants; indole acetic acid
Abstract:
... Ethylene formation was studied in 5- to 6-d-old Chenopodium rubrum seedlings under the following light regimes: continuous light (CL), continuous darkness (CD), and alternating light/darkness (12 h of each). No significant regular oscillations in ethylene formation were found in either the CL or CD groups. In the light/dark regime, pronounced diurnal fluctuations in ethylene formation were observe ...

12. Extracellular matrix assembly in diatoms (Bacillariophyceae). II. 2,6-dichlorobenzonitrile inhibition of motility and stalk production in the marine diatom Achnanthes longipes

Author:
Wang, Y.; Lu, J.; Mollet, J.C.; Gretz, M.R.; Hoagland, K.D.
Source:
Plant physiology 1997 v.113 no.4 pp. 1071-1080
ISSN:
0032-0889
Subject:
nitrile herbicides; biosynthesis; dose response; plant anatomy; developmental stages; adhesion; polymers; immunocytochemistry; Bacillariophyta
Abstract:
... The cellulose synthesis inhibitor 2,6-dichlorobenzonitrile (DCB) and the DCB analogs 2-chloro-6-fluorobenzonitrile, 3-amino-2,6-dichlorobenzonitrile, and 5-dimethylamino-naphthalene-1-sulfonyl-(3-cyano-2, 4-dichloro)aniline (DCBF) inhibited extracellular adhesive production in the marine diatom Achnanthes longipes resulting in a loss of motility and a lack of permanent adhesion. The effect was ful ...

13. Gibberellins and stem growth in Arabidopsis thaliana. Effects of photoperiod on expression of the GA4 and GA5 loci

Author:
Xu, Y.L.; Gage, D.A.; Zeevaart, J.A.D.
Source:
Plant physiology 1997 v.114 no.4 pp. 1471-1476
ISSN:
0032-0889
Subject:
Arabidopsis thaliana; flowering; dose response; loci; stems; genetic code; gene expression; genes; gibberellins; enzyme activity; oxygenases; photoperiod
Abstract:
... Arabidopsis thaliana (L.) Heynh. is a quantitative long-day (LD) rosette plant in which stem growth is mediated by gibberellins (GAs). Application of GAs to plants in short-day (SD) conditions resulted in rapid stem elongation and flower formation, with GA4 and GA9 being equally effective, and GA1 showing lower activity. The effects of photoperiod on the levels of endogenous GAs were measured by c ...
PubMed:
9276956
PubMed Central:
PMC158440

14. Growth and N allocation in rice plants under CO2 enrichment

Author:
Makino, A.; Harada, M.; Sato, T.; Nakano, H.; Mae, T.
Source:
Plant physiology 1997 v.115 no.1 pp. 199-203
ISSN:
0032-0889
Subject:
Oryza sativa; leaves; roots; nitrogen; dose response; nutrient uptake; nutrient transport; photoperiod; night temperature; biomass; leaf area index; nitrogen content; carbon dioxide
Abstract:
... The effects of CO2 enrichment on growth and N allocation of rice (Oryza sativa L.) were examined. The plants were grown hydroponically in growth chambers with a 14-h photoperiod (1000 micromole quanta m-2 s-1) and a day/night temperature of 25/20 degrees C. From the 28th to 70th d after germination, the plants were exposed to two CO2 partial pressures, namely 36 and 100 Pa. The CO2 enrichment incr ...

15. Growth, water relations, and accumulation of organic and inorganic solutes in roots of maize seedlings during salt stress

Author:
Gonzalez Rodriguez, H.; Roberts, J.K.M.; Jordan, W.R.; Drew, M.C.
Source:
Plant physiology 1997 v.113 no.3 pp. 881-893
ISSN:
0032-0889
Subject:
salt tolerance; root tips; Zea mays; dose response; biosynthesis; cell growth; salinity; seedlings; organic compounds; osmotic pressure; stress response; vacuoles; cell division; solutes; plant-water relations; sodium chloride; measurement
Abstract:
... Seedlings of maize (Zea mays L. cv Pioneer 3906), hydroponically grown in the dark, were exposed to NaCl either gradually (salt acclimation) or in one step (salt shock). In the salt-acclimation treatment, root extension was indistinguishable from that of unsalinized controls for at least 6 d at concentrations up to 100 mM NaCl. By contrast, salt shock rapidly inhibited extension, followed by a gra ...

16. Hormonal regulation of dormancy in developing sorghum seeds

Author:
Steinbach, H.S.; Benech-Arnold, R.L.; Sanchez, R.A.
Source:
Plant physiology 1997 v.113 no.1 pp. 149-154
ISSN:
0032-0889
Subject:
Sorghum bicolor; seed development; seed dormancy; seed germination; abscisic acid; gibberellic acid; biosynthesis; fluridone; paclobutrazol; dose response; cultivars; genetic variation; pollination; genotype; biological resistance
Abstract:
... The role of abscisic acid (ABA) and gibberellic acid (GA) in determining the dormancy level of developing sorghum (Sorghum bicolor [L.] Moench.) seeds from varieties presenting contrasting preharvest sprouting behavior (Redland B2,susceptible; IS 9530, resistant) was investigated. Panicles from both varieties were sprayed soon after pollination with fluridone or paclobutrazol to inhibit ABA and GA ...

17. Identification and characterization of linoleic acid as an endogenous modulator of in vitro N-1-naphthylphthalamic acid binding

Author:
Suttle, J.C.
Source:
Plant physiology 1997 v.113 no.2 pp. 519-525
ISSN:
0032-0889
Subject:
naphthalene; linoleic acid; in vitro culture; dose response; nutrient transport; microsomes; phthalates; auxins; binding sites; epicotyls; structure-activity relationships; chemical constituents of plants; Pisum sativum
Abstract:
... An endogenous inhibitor of the in vitro binding of the phytotropin N-1-naphthylphthalamic acid to microsomal membranes was detected in extracts prepared from etiolated pea (Pisum sativum L.) epicotyls. Following extensive purification, the inhibitor was identified as linoleic acid. Authentic linoleic acid inhibited N-1-naphthylphthalamic acid binding noncompetitively in a dose-dependent manner, ex ...

18. Inorganic carbon accumulation stimulates linear electron flow to artificial electron acceptors of photosystem I in air-grown cells of the cyanobacterium synechococcus UTEX 625

Author:
Li, Q.L.; Canvin, D.T.
Source:
Plant physiology 1997 v.114 no.4 pp. 1273-1281
ISSN:
0032-0889
Subject:
Synechococcus; cultured cells; light intensity; photosystem I; photosystem II; glycols; aldehydes; carbon; inorganic compounds; dose response; nutrient transport; oxygen; gas exchange; aerobic conditions; anaerobic conditions; light harvesting complex; electron transfer
Abstract:
... The effect of inorganic carbon (Ci) transport and accumulation on photosynthetic electron transport was studied in air-grown cells of the cyanobacterium Synechococcus UTEX 625. When the cells were depleted of Ci, linear photosynthetic electron flow was almost completely inhibited in the presence of the photosystem I (PSI) acceptor N,N-dimethyl-p-nitrosoaniline (PNDA). The addition of Ci to these c ...

19. Involvement of thylakoid overenergization in tentoxin-induced chlorosis in Nicotiana spp

Author:
Holland, N.; Evron, Y.; Jansen, M.A.K.; Edelman, M.; Pick, U.
Source:
Plant physiology 1997 v.114 no.3 pp. 887-892
ISSN:
0032-0889
Subject:
seedlings; plant pathogenic fungi; Nicotiana plumbaginifolia; dose response; Nicotiana tabacum; Alternaria alternata; chlorosis; oxygen; adenosinetriphosphatase; superoxide dismutase; adenosine triphosphate; pathogenicity; enzyme activity; gramicidin; ascorbic acid; biosynthesis; free radicals; thylakoids; transgenic plants; photophosphorylation; mutants
Abstract:
... The purpose of this work was to clarify the mechanism of tentoxin-induced chlorosis inNicotiana spp. seedlings. We found that chlorosis does not correlate with the inhibition of chloroplast ATP synthesis in vivo, since it occurs at tentoxin concentrations far higher than that required for the inhibition of photophosphorylation measured in the same seedlings. However, tentoxin-induced chlorosis doe ...

20. Isoprene increases thermotolerance of isoprene-emitting species

Author:
Singsass, E.L.; Lerdau, M.; Winter, K.; Sharkey, T.D.
Source:
Plant physiology 1997 v.115 no.4 pp. 1413-1420
ISSN:
0032-0889
Subject:
Pueraria montana var. lobata; Quercus alba; Phaseolus vulgaris; leaves; heat stress; dose response; temperature; isoprenoids; quantitative analysis; chlorophyll; fluorescence; cell membranes; hydrophobicity; emissions; stress response
Abstract:
... Isoprene-emitting plants lose a large portion of their assimilated C as isoprene. Because isoprene synthesis can be regulated, it has been assumed that isoprene benefits the plant. Since the rate of isoprene emission from leaves is highly responsive to temperature, we hypothesized that isoprene benefits plants by increasing their thermotolerance. We used three methods to measure isoprene-induced t ...

21. Local and systemic responses to antioxidants to tobacco mosaic virus infection and to salicylic acid to tobacco. Role in systemic acquired resistance

Author:
Fodor, J.; Gullner, G.; Adam, A.L.; Barna, B.; Komives, T.; Kiraly, Z.
Source:
Plant physiology 1997 v.114 no.4 pp. 1443-1451
ISSN:
0032-0889
Subject:
dehydroascorbic acid; necrosis; salicylic acid; Tobacco mosaic virus; glutathione; dose response; glutathione transferase; Nicotiana tabacum; disease resistance; leaves; quantitative analysis; superoxide dismutase; pathogenicity; enzyme activity; isozymes; antioxidants; ascorbic acid; glutathione-disulfide reductase; catalase; chemical constituents of plants
Abstract:
... Changes in ascorbate and glutathione levels and in activitiesof ascorbate peroxidase, catalase, dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione S-transferase (GST), and superoxide dismutase (SOD) were investigated in tobacco mosaic virus (TMV)-inoculated lower leaves and in noninoculated upper leaves of Nicotiana tabacum L. cv Xanthi-nc. In separate experiments the effec ...

22. Mechanosensitive expression of a lipoxygenase gene in wheat

Author:
Mauch, F.; Kmecl, A.; Schaffrath, U.; Volrath, S.; Gorlach, J.; Ward, E.; Ryals, J.; Dudler, R.
Source:
Plant physiology 1997 v.114 no.4 pp. 1561-1566
ISSN:
0032-0889
Subject:
messenger RNA; wind; dose response; seedlings; stress response; linoleate 13S-lipoxygenase; amino acid sequences; gene expression; transcription (genetics); Triticum aestivum; genes; enzyme activity
Abstract:
... Touch stimulation of wheat (Triticum aestivum L.) seedlings led to a strong and dose-dependent increase in the level of lipoxygenase mRNA transcripts. The touch-induced response occurred within 1 h and was transient. A similar response was observed after wind treatment and wounding. The mechanical strain-regulated lipoxygenase might translate mechanical strain into lipoxygenase pathway-dependent g ...
PubMed:
9276964
PubMed Central:
PMC158451

23. Negative regulation in the expression of a sugar-inducible gene in Arabidopsis thaliana. A recessive mutation causing enhanced expression of a gene for beta-amylase

Author:
Mita, S.; Hirano, H.; Nakamura, K.
Source:
Plant physiology 1997 v.114 no.2 pp. 575-582
ISSN:
0032-0889
Subject:
Arabidopsis thaliana; anthocyanins; messenger RNA; dose response; chemical constituents of plants; glucose; sucrose; transgenic plants; starch; gene expression; cultured cells; genes; mutants; petioles; genetic variation; enzyme activity; beta-amylase
Abstract:
... Expression of a beta-amylase gene of Arabidopsis thaliana (AT beta-Amy) is regulated by sugars. We identified a mutant, hba1, in which the level of expression of AT beta-Amy in leaves of plants that had been grown in a medium with 2% sucrose was significantly higher than that in wild-type plants. Higher than wild-type levels of beta-amylase in hba1 plants depended on the presence of 1 to 2% sucros ...
PubMed:
9193090
PubMed Central:
PMC158338

24. Nitrogenase activity is affected by reduced partial pressures of N2 and NO3-

Author:
Blumenthal, J.M.; Russelle, M.P.; Vance, C.P.
Source:
Plant physiology 1997 v.114 no.4 pp. 1405-1412
ISSN:
0032-0889
Subject:
nitrogen fixation; dose response; symbiosis; nitrogen; Medicago sativa; Ensifer meliloti; ion transport; nitrogenase; enzyme activity; nitrates; measurement
Abstract:
... Optimal use of legumes in cropping systems requires a thorough understanding of the interaction between inorganic N nutrition and symbiotic N2 fixation. Our objective was to test the hypothesis that increased NO3(-) uptake by alfalfa (Medicago sativa L.) would compensate for lower N2 fixation caused by low partial pressure of N2. Root systems of hydroponically grown alfalfa at 2 mg L-1 NO3(-)-N we ...

25. Quantum yields and rate constants of photochemical and nonphotochemical excitation quenching. Experiment and model

Author:
Laisk, A.; Oja, V.; Rasulov, B.; Eichelmann, H.; Sumberg, A.
Source:
Plant physiology 1997 v.115 no.2 pp. 803-815
ISSN:
0032-0889
Subject:
Helianthus annuus; ion transport; light intensity; photoinhibition; measurement; carbon dioxide; dose response; Gossypium hirsutum; light harvesting complex; electron transfer; Sorghum bicolor; Nicotiana tabacum; leaves; Amaranthus cruentus; mathematical models; equations; net assimilation rate; temperature; prediction; cytochrome b
Abstract:
... Sunflower (Helianthus annuus L.), cotton (Gossypium hirsutum L.), tobacco (Nicotiana tabacum L.), sorghum (Sorghum bicolor Moench.), amaranth (Amaranthus cruentus L.), and cytochrome b6f complex-deficient transgenic tobacco leaves were used to test the response of plants exposed to different light intensities and CO2 concentrations before and after photoinhibition at 4000 micromoles photons m-2 s- ...

26. Regulation of the accumulation and reduction of nitrate by nitrogen and carbon metabolites in maize seedlings

Author:
Sivasankar, S.; Rothstein, S.; Oaks, A.
Source:
Plant physiology 1997 v.114 no.2 pp. 583-589
ISSN:
0032-0889
Subject:
Zea mays; seedlings; roots; shoots; nitrate reduction; nitrogen; carbon; metabolites; asparagine; glutamine; sucrose; dose response; nutrient uptake; nitrate reductase; enzyme activity; nitrite reductase; aspartate-ammonia ligase; genes; gene expression; transcription (genetics)
Abstract:
... The accumulation and reduction of nitrate in the presence of the nitrogen metabolites asparagine (Asn) and glutamine (Gln) and the carbon metabolite sucrose (Suc) were examined in maize (Zea mays L.) seedlings in an attempt to separate their effects on the nitrate uptake system and the nitrate reduction system. After 8 h of exposure to nitrate in the presence of 1 mM Asn, tissue nitrate accumulati ...

27. Restoration of phototropic responsiveness in decapitated maize coleoptiles

Author:
Kaldenhoff, R.; Iino, M.
Source:
Plant physiology 1997 v.114 no.4 pp. 1267-1272
ISSN:
0032-0889
Subject:
Zea mays; coleoptiles; decapitation; photoreceptors; phototropism; blue light; shade; lanolin; dose response; translocation (plant physiology); indole acetic acid
Abstract:
... The literature indicates that the tip of maize (Zea mays L.) coleoptiles has the localized functions of producing auxin for growth and perceiving unilateral light stimuli and translocating auxin laterally for phototropism. There is evidence that the auxin-producing function of the tip is restored in decapitated coleoptiles. We examined whether the functions for phototropism are also restored by us ...
PubMed:
11536822
PubMed Central:
PMC158419

28. Salicylic acid is needed in hypersensitive cell death in soybean but does not act as a catalase inhibitor

Author:
Tenhaken, R.; Rubel, C.
Source:
Plant physiology 1997 v.115 no.1 pp. 291-298
ISSN:
0032-0889
Subject:
metabolism; Glycine max; dose response; catalase; necrosis; hydrogen peroxide; virulence; enzyme inhibitors; cultured cells; genes; salicylic acid; oxidation; disease resistance; Pseudomonas syringae pv. glycinea; peroxidase; metabolites; ascorbic acid
Abstract:
... The function of salicylic acid (SA) in hypersensitive cell death was studied in a soybean (Glycine max)-Pseudomonas syringae pv glycinea system. The infection of cell cultures with bacteria leads to a hypersensitive reaction (HR), which is dependent on an appropriate avirulence gene and on low concentrations of SA. The requirements for SA is essential for a process shortly before the onset of the ...

29. Seed germination of Arabidopsis thaliana phyA/phyB double mutants is under phytochrome control

Author:
Poppe, C.; Schafer, E.
Source:
Plant physiology 1997 v.114 no.4 pp. 1487-1492
ISSN:
0032-0889
Subject:
Arabidopsis thaliana; seed dormancy; dormancy breaking; imbibition; seed germination; phytochrome; red light; far-red light; dose response; morphogenesis; mutants; genetic variation
Abstract:
... We examined the photocontrol of seed germination in the phyA/phyB double mutants of Arabidopsis thaliana seeds. Dormant phyA/phyB seeds showed a red/far-red light (R/FR)-reversible induction of seed germination. This suggests the involvement of at least one other phytochrome, phyC, D, and/or E, in controlling seed germination. We designated this spectrally active phytochrome in phyA/phyB as phyX. ...
PubMed:
9276958
PubMed Central:
PMC158442

30. Sterol modulation of the plasma membrane H+-ATPase activity from corn roots reconstituted into soybean lipids

Author:
Grandmougin-Ferjani, A.; Schuler-Muller, I.; Hartmann, M.A.
Source:
Plant physiology 1997 v.113 no.1 pp. 163-174
ISSN:
0032-0889
Subject:
ion transport; measurement; dose response; morpholine fungicides; hydrogen; plasma membrane; adenosinetriphosphatase; protein composition; phospholipids; Zea mays; Glycine max; adenosine triphosphate; enzyme inhibitors; hydrolysis; proton pump; enzyme activity; stigmasterol; cholesterol; pH; binding sites; triazole fungicides
Abstract:
... A partially purified H+-ATPase from the plasma membrane (PM) of corn (Zea mays L.) roots was inserted into vesicles prepared with soybean (Glycine max L.) phospholipids and various concentrations of individual sterols using either a freeze-thaw sonication or an octylglucoside dilution procedure. Both methods yielded a functional enzyme that retained its native characteristics. We have investigated ...

31. Substrate kinetics of the plant mitochondrial alternative oxidase and the effects of pyruvate

Author:
Hoefnagel, M.H.N.; Rich, P.R.; Zhang, Q.; Wiskich, J.T.
Source:
Plant physiology 1997 v.115 no.3 pp. 1145-1153
ISSN:
0032-0889
Subject:
inflorescences; Glycine max; dose response; pyruvic acid; cotyledons; oxidoreductases; ubiquinones; mitochondria; oxidation; Arum italicum; kinetics; enzyme activity; protein composition; measurement
Abstract:
... The kinetics of alternative oxidase (AOX) of Arum italicum spadices and soybean (Glycine max L.) cotyledons were studied both with intact mitochondria and with a solubilized, partially purified enzyme. Ubiquinone analogs were screened for their suitability as substrates and ubiquinol-1 was found to be most suitable. The kinetics of ubiquinol-1 oxidation via AOX in both systems followed Michaelis-M ...

32. Sugar-dependent gibberellin-induced chalcone synthase gene expression in petunia corollas

Author:
Moalem-Beno, D.; Tamari, G.; Leitner-Dagan, Y.; Borochov, A.; Weiss, D.
Source:
Plant physiology 1997 v.113 no.2 pp. 419-424
ISSN:
0032-0889
Subject:
anthocyanins; biosynthesis; dose response; Petunia hybrida; corolla; sucrose; naringenin-chalcone synthase; gibberellic acid; nutrient uptake; gene expression; enzyme activity
Abstract:
... The induction of anthocyanin synthesis and anthocyanin biosynthetic gene expression in detached petunia (Petunia hybrida) corollas by gibberellic acid (GA3) requires sucrose. Neither sucrose nor GA3 alone can induce these processes. We found that GA3 enhances sucrose uptake by 20 to 30%, and we tested whether this is the mechanism by which the hormone induces gene expression. Changing the intracel ...

33. Turnover of galactans and other cell wall polysaccharides during development of flax plants

Author:
Gorshkova, T.A.; Chemikosova, S.B.; Lozovaya, V.V.; Carpita, N.C.
Source:
Plant physiology 1997 v.114 no.2 pp. 723-729
ISSN:
0032-0889
Subject:
plant development; galactans; biosynthesis; cell growth; radiolabeling; galactose; Linum usitatissimum; developmental stages; xylose; arabinose; dose response; phloem; cell wall components; cell differentiation; metabolites
Abstract:
... We investigated the synthesis and turnover of cell wall polysaccharides of the flax (Linum usitatissimum L.) plant during development of the phloem fibers. One-month-old flax plants were exposed to a 40-min pulse with 14CO2 followedby 8-h, 24-h, and 1-month periods of chase with ambient CO2, and radioactivity in cell wall sugars was determined in various plant parts. The relative radioactivity of ...

34. ZEA3: a negative modulator of cytokinin responses in plant seedlings

Author:
Martin, T.; Sotta, B.; Jullien, M.; Caboche, M.; Faure, J.D.
Source:
Plant physiology 1997 v.114 no.4 pp. 1177-1185
ISSN:
0032-0889
Subject:
seedling growth; plant development; dose response; phenotype; hypocotyls; cell growth; developmental stages; cotyledons; cell division; gene expression; benzyladenine; mutants; length; genes; genetic variation; Nicotiana plumbaginifolia; plant morphology; roots
Abstract:
... In Nicotiana plumbaginifolia cytokinins affect seedling development by inhibiting root growth and hypocotyl elongation and by stimulating cotyledon expansion. The zea3.1 mutant was selected for its inability to grow in conditions of low nitrogen and for its ability to grow independently on inhibitory concentrations of zeatin (J.D. Faure, M. Jullien, M. Caboche [1994] Plant J 5: 481-491). The zea3. ...

35. The ascorbate carrier of higher plant plasma membranes preferentially translocates the fully oxidized (dehydroascorbate) molecule

Author:
Horemans, N.; Asard, H.; Caubergs, R.J.
Source:
Plant physiology 1997 v.114 no.4 pp. 1247-1253
ISSN:
0032-0889
Subject:
glutathione; dose response; radiolabeling; enzyme activity; dithiothreitol; cytosol; Phaseolus vulgaris; oxidoreductases; thiourea; binding proteins; translocation (plant physiology); oxidation; plasma membrane; cyanides; thiols; cysteine; ascorbic acid
Abstract:
... Recently, the uptake of 14C-labeled ascorbate (ASC) into highly purified bean (Phaseolus vulgaris L.) plasma membrane vesicles was demonstrated in our laboratory. However, the question of the redox status of the transported molecule (ASC or dehydroascorbate [DHA]) remained unanswered. In this paper we present evidence that DHA is transported through the plasma membrane. High-performance liquid chr ...

36. The effect of elevated partial pressures of CO2 on the relationship between photosynthetic capacity and N content in rice leaves

Author:
Nakano, H.; Makino, A.; Mae, T.
Source:
Plant physiology 1997 v.115 no.1 pp. 191-198
ISSN:
0032-0889
Subject:
ribulose-bisphosphate carboxylase; carbon dioxide; nitrogen content; protein content; dose response; nitrogen; Oryza sativa; osmotic pressure; nutrient availability; net assimilation rate; cytochrome f; sucrose synthase; phosphates; photosynthesis; light; chlorophyll; enzyme activity; leaves
Abstract:
... The effects of growth CO2 levels on the photosynthetic rates; the amounts of ribulose-1,5-bisphosphate carboxylase (Rubisco), chlorophyll (Chl), and cytochrome f; sucrose phosphate synthase activity; and total N content were examined in young, fully expanded leaves of rice (Oryza sativa L.). The plants were grown hydroponically under two CO2 partial pressures of 36 and 100 Pa at three N concentrat ...

37. The effects of salicylic acid and tobacco mosaic virus infection on the alternative oxidase of tobacco

Author:
Lennon, A.M.; Neuenschwander, U.H.; Ribas-Carbo, M.; Giles, L.; Ryals, J.A.; Siedow, J.N.
Source:
Plant physiology 1997 v.115 no.2 pp. 783-791
ISSN:
0032-0889
Subject:
Nicotiana tabacum; leaves; cell suspension culture; mitochondria; Tobacco mosaic virus; pathogenicity; disease resistance; salicylic acid; dose response; enzyme activity; oxygenases; pathogenesis; messenger RNA; measurement; cytochromes; transgenic plants; gene expression; electron transfer; systemic acquired resistance
Abstract:
... Salicylic acid (SA) is a signal in systemic acquired resistance and an inducer of the alternative oxidase protein in tobacco (Nicotiana tabacum cv Xanthi nc) cell suspensions and during thermogenesis in aroid spadices. The effects of SA on the levels of alternative oxidase protein and the pathogenesis-related 1a mRNA (a marker for systemic acquired resistance), and on the partitioning of electrons ...

38. The massugu1 mutation of arabidopsis identified with failure of auxin-induced growth curvature of hypocotyl confers auxin insensitivity to hypocotyl and leaf

Author:
Watahiki, M.K.; Yamamoto, K.T.
Source:
Plant physiology 1997 v.115 no.2 pp. 419-426
ISSN:
0032-0889
Subject:
1-aminocyclopropane-1-carboxylic acid; Arabidopsis thaliana; hypocotyls; roots; dose response; mutants; genetic variation; loci; chromosome mapping; recessive genes; 2,4-D; benzyladenine; abscisic acid; plant morphology; phenotype; indole acetic acid; etiolation
Abstract:
... Unilateral application of indole-3-acetic acid (IAA) in a lanolin base to hypocotyls of partially etiolated seedlings of wild-type Arabidopsis thaliana induced growth curvature in a dose-dependent manner. The effects of IAA in concentrations from 1 to 1000 micromolar were studied, with maximum IAA-induced curvature at 100 micromolar. Three IAA-insensitive mutants were isolated and are all in the s ...
PubMed:
9342863
PubMed Central:
PMC158499

39. ATP hydrolysis activity and polymerization state of ribulose-1,5-bisphosphate carboxylase oxygenase activase. Do the effects of Mg2+, K+, and activase concentrations indicate a functional similarity to actin?

Author:
Lilley, R.M.; Portis, A.R. Jr.
Source:
Plant physiology 1997 v.114 no.2 pp. 605-613
ISSN:
0032-0889
Subject:
ribulose-bisphosphate carboxylase; dose response; polymerization; Spinacia oleracea; adenosine triphosphate; magnesium; biochemical pathways; anions; potassium; hydrolysis; actin; enzyme activity; adenosinetriphosphatase
Abstract:
... The ATPase activity and fluorescence of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) activase were determined over a range of MgCl2, KCl, and activase concentrations. Both salts promoted ADP release from ATP and intrinsic fluorescence enhancement by adenosine 5'-[gamma-thio] triphosphate, but Mg2+ was about 10 times more effective than K+. ATPase and fluorescence enhancement both incr ...

40. Acetaldehyde is a causal agent responsible for ethanol-induced ripening inhibition in tomato fruit

Author:
Beaulieu, J.C.; Peiser, G.; Saltveit, M.E.
Source:
Plant physiology 1997 v.113 no.2 pp. 431-439
ISSN:
0032-0889
Subject:
temperature; Solanum lycopersicum var. lycopersicum; ripening; ethanol; dose response; acetaldehyde; biosynthesis; quantitative analysis; alcohol dehydrogenase; aldehyde dehydrogenase; enzyme inhibitors
Abstract:
... Inhibition of tomato (Lycopersicon esculentum Mill.) fruit ripening by exogenously applied ethanol was shown to be caused by elevated endogenous levels of acetaldehyde (AA). Exposure of excised pericarp discs of mature-green tomato fruit to ethanol or AA vapors produced elevated levels of both compounds in the tissue, but only the levels of AA were associated with ripening inhibition. Ripening inh ...

41. Activation of pollen tube callose synthase by detergents. Evidence for different mechanisms of action

Author:
Li, H.J.; Bacic, A.; Read, S.M.
Source:
Plant physiology 1997 v.114 no.4 pp. 1255-1265
ISSN:
0032-0889
Subject:
Nicotiana alata; pollen tubes; callose; biosynthesis; hexosyltransferases; detergents; digitonin; dose response; pyridoxal; sulfonates; phosphatidylcholines; trypsin; cell wall components; beta-glucans
Abstract:
... In pollen tubes of Nicotiana alata, a membrane-bound, Ca2+-independent callose synthase (CalS) is responsible for the biosynthesis of the (1,3)-beta-glucan backbone of callose, the main cell wall component. Digitonin increases CalS activity 3- to 4-fold over a wide range of concentrations, increasing the maximum initial velocity without altering the Michaelis constant for UDP-glucose. The CalS act ...
PubMed:
9276948
PubMed Central:
PMC158418

42. Al-induced, 51-kilodalton, membrane-bound proteins are associated with resistance to Al in a segregating population of wheat

Author:
Taylor, G.J.; Basu, A.; Basu, U.; Slaski, J.J.; Zhang, G.; Good, A.
Source:
Plant physiology 1997 v.114 no.1 pp. 363-372
ISSN:
0032-0889
Subject:
cultivars; sulfur; protein synthesis; dose response; quantitative analysis; callose; phytotoxicity; radiolabeling; stress response; cytosol; microsomes; Triticum aestivum; aluminum; mitochondria; tonoplast; genetic variation; plasma membrane; genotype; protein composition
Abstract:
... Incorporation of 35S into protein is reduced by exposure to Al in wheat (Triticum aestivum), but the effects are genotype-specific. Exposure to 10 to 75 micromolars Al had little effect on 35S incorporation into total protein, nuclear and mitochondrial protein, microsomal protein, and cytosolic protein in the Al-resistant cultivar PT741. In contrast, 10 micromolars Al reduced incorporation by 21 t ...

43. Blockage of brassinosteroid biosynthesis and sensitivity causes dwarfism in garden pea

Author:
Nomura, T.; Nakayama, M.; Reid, J.B.; Takeuchi, Y.; Yokota, T.
Source:
Plant physiology 1997 v.113 no.1 pp. 31-37
ISSN:
0032-0889
Subject:
height; plant characteristics; Pisum sativum; seedlings; shoots; brassinosteroids; biosynthesis; quantitative analysis; chemical reactions; biochemical pathways; internodes; dose response; length; dwarfing; mutants; genetic variation; chemical constituents of plants; genotype; width
Abstract:
... Endogenous brassinosteroids (BRs) in the dwarf mutants Ika and Ikb of garden pea (Pisum sativum L.) and comparable wild-type plants were quantified by gas chromatography-selected ion monitoring using deuterated internal standards. In young shoots of the Ikb mutant, the levels of brassinolide, castasterone, and 6-deoxocastasterone were 23-, 22-, and 9-fold lower, respectively, than those of wild-ty ...

44. Ca2+ and calmodulin dynamics during photopolarization in Fucus serratus zygotes

Author:
Love, J.; Brownlee, C.; Trewavas, A.J.
Source:
Plant physiology 1997 v.115 no.1 pp. 249-261
ISSN:
0032-0889
Subject:
developmental stages; trifluoperazine; Fucus serratus; cytochalasin B; dose response; Ascophyllum; clones; gene expression; zygote; messenger RNA; lanthanum; calcium; polymerization; culture media; calmodulin; plant anatomy; chlorides; verapamil; fertilization (reproduction); light; ethylene glycol tetraacetic acid
Abstract:
... The role of Ca2+ in zygote polarization in fucoid algae (Fucus, Ascophyllum, and Pelvetia species) zygote polarization is controversial. Using a local source of Fucus serratus, we established that zygotes form a polar axis relative to unilateral light (photopolarization) between 8 and 14 h after fertilization (AF), and become committed to this polarity at approximately 15 to 18 h AF. We investigat ...

45. Cloning and overexpression of two cDNAs encoding the low-CO2-inducible chloroplast envelope protein LIP-36 from Chlamydomonas reinhardtii

Author:
Chen, Z.Y.; Lavigne, L.L.; Mason, C.B.; Moroney, J.V.
Source:
Plant physiology 1997 v.114 no.1 pp. 265-273
ISSN:
0032-0889
Subject:
Chlamydomonas reinhardtii; gene expression; complementary DNA; genetic code; chloroplasts; plant proteins; carbon dioxide; dose response; photorespiration; amino acid sequences; restriction mapping
Abstract:
... Chlamydomonas reinhardtii, a unicellular green alga, grows photoautotrophically at very low concentrations of inorganic carbon due to the presence of an inducible CO2-concentrating mechanism. During the induction of the CO2-concentrating mechanism at low-CO2 growth conditions, at least five polypeptides that are either absent or present in low amounts in cells grown on high-CO2 concentrations are ...
PubMed:
9159951
PubMed Central:
PMC158302

46. Cold acclimation and freezing tolerance. A complex interaction of light and temperature

Author:
Gary, G.R.; Chauvin, L.P.; Sarhan, F.; Huner, N.P.A.
Source:
Plant physiology 1997 v.114 no.2 pp. 467-474
ISSN:
0032-0889
Subject:
messenger RNA; dose response; redox reactions; net assimilation rate; light intensity; acclimation; Secale cereale; gene expression; transcription (genetics); frost resistance; photosynthesis; genes; temperature; plant morphology; chloroplasts
Abstract:
... By comparing growth under five different temperature and irradiance regimes (20 degrees C and 800, 250, and 50 micromoles m-2 s-1 and 5 degrees C and 250 and 50 micromoles m-2 s-1), we have examined the effects of light, temperature, and the relative reduction state of photosystem II on plant morphology, freezing tolerance (lethal temperature at which freezing injury occurs [LT50]), transcript lev ...

47. Desensitization and dark recovery of the photoreceptor current in Chlamydomonas reinhardtii

Author:
Govorunova, E.G.; Sineshchekov, O.A.; Hegemann, P.
Source:
Plant physiology 1997 v.115 no.2 pp. 633-642
ISSN:
0032-0889
Subject:
dose response; calcium; photosensitivity disorders; ion transport; cell membranes; potassium; Chlamydomonas reinhardtii; phototaxis; photoreceptors; light
Abstract:
... Photoexcitation of rhodopsin in Chlamydomonas reinhardtii triggers a complex of rapid bioelectric processes in the cell membrane. Photoreceptor and flagellar currents are the major components of this cascade and are the basis for the phototaxis and photoshock response, respectively. Desensitization and dark recovery of the extracellularly recorded photoreceptor current were investigated in double- ...

48. Dynamics of acetaldehyde production during anoxia and post-anoxia in red bell pepper studied by photoacoustic techniques

Author:
Zuckerman, H.; Harren, F.J.M.; Reuss, J.; Parker, D.H.
Source:
Plant physiology 1997 v.113 no.3 pp. 925-932
ISSN:
0032-0889
Subject:
Capsicum annuum; oxygen; dose response; hypoxia; acetaldehyde; ethanol; fermentation; catalase; enzyme activity; carbon dioxide; biosynthesis; measurement; tricarboxylic acid cycle; volatile compounds; acoustic properties; stress response
Abstract:
... Acetaldehyde (AA), ethanol, and CO2 production in red bell pepper (Capsicum annum L.) fruit has been measured in a continuous flow system as the fruit was switched between 20% O2 and anaerobic conditions. Minimum gas phase concentrations of 0.5 nL L-1, 10 nL L-1, and 1 mL L-1, respectively, can be detected employing a laser-based photoacoustic technique. This technique allows monitoring of low pro ...

49. Effect of xyloglucan oligosaccharides on growth, viscoelastic properties, and long-term extension of pea shoots

Author:
Cutillas-Iturralde, A.; Lorences, E.P.
Source:
Plant physiology 1997 v.113 no.1 pp. 103-109
ISSN:
0032-0889
Subject:
Pisum sativum; shoots; internodes; length; cell walls; growth regulators; xyloglucans; oligosaccharides; dose response; pH; temperature
Abstract:
... The growth-promoting effect of xyloglucan-derived oligosaccharides was investigated using a bioassay with entire pea (Pisum sativum L., var Alaska) shoots. After a 24-h incubation period at 25 degrees C, xyloglucan oligosaccharide (XGO) solutions with concentrations of 10(-6) M notably increased the growth rate of pea shoots whereas the same oligosaccharides at 10(-7) M were less effective. To inv ...

50. Effects of osmoprotectants upon NaCl stress in rice

Author:
Garcia, A.B.; Almeida Engler, J. de.; Iyer, S.; Gerats, T.; Montagu, M. van.; Caplan, A.B.
Source:
Plant physiology 1997 v.115 no.1 pp. 159-169
ISSN:
0032-0889
Subject:
salt tolerance; biosynthesis; dose response; quantitative analysis; salinity; Oryza sativa; osmotic pressure; developmental stages; proline; stress response; trehalose; gene expression; genetic markers; genes; sodium chloride; chlorophyll; roots; leaves
Abstract:
... Plants accumulate a number of osmoprotective substances in response to NaCl stress, one of them being proline (Pro). While characterizing some of the changes in solute accumulation in NaCl-stressed rice (Oryza sativa L.), we identified several other potential osmoprotectants. One such substance, trehalose, begins to accumulate in small amounts in roots after 3 d. We performed a series of experimen ...

51. Gas exchange and C allocation in Dunaliella salina cells in response to the N source and CO2 concentration used for growth

Author:
Giordano, M.; Bowes, G.
Source:
Plant physiology 1997 v.115 no.3 pp. 1049-1056
ISSN:
0032-0889
Subject:
Dunaliella; cultured cells; cell growth; photosynthesis; net assimilation rate; light; nitrogen; carbon dioxide; dose response; culture media; ammonia; nitrates; cell division; ribulose-bisphosphate carboxylase; phosphoenolpyruvate carboxylase; carbonate dehydratase; enzyme activity; protein synthesis; chlorophyll; beta-carotene; osmotic pressure; chemical constituents of plants
Abstract:
... The halotolerant alga Dunaliella salina was cultured on 10 mM NH4+ or NO3- with air CO2 or 5% (v/v) CO2. Cells grown on NH4+ rather than NO3- were up to 17% larger in volume but had similar division rates. The photosynthetic K0.5 of dissolved inorganic C per cell was reduced, but the light- and CO2-saturated photosynthesis, dark respiration, and light-independent fixation rates were increased. The ...

52. Gene-expression patterns and levels of jasmonic acid in rice treated with the resistance inducer 2,6-dichloroisonicotinic acid

Author:
Schweizer, P.; Buchala, A.; Metraux, J.P.
Source:
Plant physiology 1997 v.115 no.1 pp. 61-70
ISSN:
0032-0889
Subject:
pathogenesis-related proteins; protein synthesis; dose response; quantitative analysis; Oryza sativa; jasmonic acid; linoleate 13S-lipoxygenase; Pseudomonas syringae; pathogenicity; gene expression; plant pathogenic fungi; disease resistance; genes; Magnaporthe grisea; chemical constituents of plants; niacin; enzyme activity; leaves
Abstract:
... Acquired disease resistance can be induced in rice (Oryza sativa) by a number of synthetic or natural compounds, but the molecular mechanisms behind the phenomenon are poorly understood. One of the synthetic inducers of resistance, 2,6-dichloroisonicotinic acid (INA), efficiently protected rice leaves from infection by the rice blast fungus Magnaporthe grisea (Hebert) Barr. A comparison of gene-ex ...

53. Heat denaturation profiles of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and Rubisco activase and the inability of Rubisco activase to restore activity of heat-denatured Rubisco

Author:
Eckardt, N.A.; Portis, A.R. Jr.
Source:
Plant physiology 1997 v.113 no.1 pp. 243-248
ISSN:
0032-0889
Subject:
plant physiology; ribulose-bisphosphate carboxylase; enzyme activity; dose response; chloroplasts; plant proteins; enzyme inhibitors; heat treatment; denaturation; temperature; dithiothreitol
Abstract:
... We compared the heat-denaturation profiles of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and Rubisco activase and further examined the ability of Rubisco activase to restore the activity of heat-denatured Rubisco originally reported (E. Sanchez de Jimenez, L. Medrano, and E. Martinez-Barajas [1995] Biochemistry 34: 2826-2831). Rubisco was heat-treated in both the carbamylated and un ...

54. Histone hyperacetylation in maize in response to treatment with HC-toxin or infection by the filamentous fungus Cochliobolus carbonum

Author:
Ransom, R.F.; Walton, J.D.
Source:
Plant physiology 1997 v.115 no.3 pp. 1021-1027
ISSN:
0032-0889
Subject:
Zea mays; dose response; histones; embryo (plant); genetic variation; developmental stages; enzyme inhibitors; mycotoxins; pathogenicity; Bipolaris zeicola; plant pathogenic fungi; acetylation; inbred lines; pathogenesis; plant morphology; genotype; isozymes; leaves; tissue culture
Abstract:
... HC-toxin, the host-selective toxin produced by the filamentous fungus Cochliobolus carbonum, inhibits maize (Zea mays L.) histone deacetylases (HDs) in vitro. Here we show that HDs are also inhibited by HC-toxin in vivo, as demonstrated by the accumulation of hyperacetylated forms of the core (nucleosomal) histones H3.1, H3.2, H3.3, and H4 in both maize embryos and tissue cultures. Hyperacetylatio ...

55. Importance of the chiral centers of jasmonic acid in the responses of plants. Activities and antagonism between natural and synthetic analogs

Author:
Holbrook, L.; Tung, P.; Ward, K.; Reid, D.M.; Abrams, S.; Lamb, N.; Quail, J.W.; Moloney, M.M.
Source:
Plant physiology 1997 v.114 no.2 pp. 419-428
ISSN:
0032-0889
Subject:
Helianthus annuus; Brassica napus; measurement; chemical degradation; dose response; jasmonic acid; gene expression; Triticum aestivum; Nicotiana tabacum; esters; stereochemistry; enzyme activity; chemical structure; seed germination; transgenic plants; cotyledons; proteinase inhibitors; reporter genes; chemical constituents of plants; chlorophyll; beta-glucuronidase
Abstract:
... The importance of the two chiral centers at C-3 and C-7 in the molecular structure of jasmonic acid in plant responses was investigated. We separated methyl jasmonate (MeJA) into (3R)- and (3S)-isomers with a fixed stereochemistry at C-3, but epimerization at C-7 is possible. The four isomers of the nonepimerizable analog 7-methyl MeJA were synthesized. These six esters and their corresponding aci ...

56. Influence of salicylic acid on H2O2 production, oxidative stress, and H2O2-metabolizing enzymes. Salicylic acid-mediated oxidative damage requires H2O2

Author:
Rao, M.V.; Paliyath, G.; Ormrod, D.P.; Murr, D.P.; Watkins, C.B.
Source:
Plant physiology 1997 v.115 no.1 pp. 137-149
ISSN:
0032-0889
Subject:
lipid peroxidation; cell membranes; salicylic acid; dose response; hydrogen peroxide; carotenes; oxidation; peroxidase; leaves; Arabidopsis thaliana; copper; superoxide dismutase; enzyme activity; ascorbic acid; biosynthesis; phytotoxicity; zinc; catalase; stress response; biochemical pathways; thiourea; protein content; chlorophyll
Abstract:
... We investigated how salicylic acid (SA) enhances H2O2 and the relative significance of SA-enhanced H2O2 in Arabidopsis thaliana. SA treatments enhanced H2O2 production, lipid peroxidation, and oxidative damage to proteins, and resulted in the formation of chlorophyll and carotene isomers. SA-enhanced H2O2 levels were related to increased activities of Cu,Zn-superoxide dismutase and were independen ...
PubMed:
9306697
PubMed Central:
PMC158469

57. Inhibitors of protein kinases and phosphatases alter root morphology and disorganize cortical microtubules

Author:
Baskin, T.I.; Wilson, J.E.
Source:
Plant physiology 1997 v.113 no.2 pp. 493-502
ISSN:
0032-0889
Subject:
Arabidopsis thaliana; cortex; microcystin-LR; dose response; morphogenesis; phosphoric monoester hydrolases; developmental stages; enzyme inhibitors; microtubules; abnormal development; deltamethrin; phosphorylation; enzyme activity; plant morphology; roots; plant proteins
Abstract:
... To investigate molecular mechanisms controlling plant morphogenesis, we examined the morphology of primary roots of Arabidopsis thaliana and the organization of cortical microtubules in response to inhibitors of serine/threonine protein phosphatases and kinases. We found that cantharidin, an inhibitor of types 1 and 2A protein phosphatases, as previously reported for okadaic acid and calyculin A ( ...
PubMed:
9046596
PubMed Central:
PMC158165

58. Regulation of acyltransferase activity in immature maize embryos by abscisic acid and the osmotic environment

Author:
Pacheco-Moises, F.; Valencia-Turcotte, L.; Altuzar-Martinez, M.; Rodriguez-Sotres, R.
Source:
Plant physiology 1997 v.114 no.3 pp. 1095-1101
ISSN:
0032-0889
Subject:
seed germination; Zea mays; biosynthesis; dose response; osmotic pressure; embryo (plant); developmental stages; triacylglycerols; mannitol; abscisic acid; enzyme activity; acyltransferases; protein composition; seed development
Abstract:
... Maize (Zea mays L.) embryos, isolated from the developing seed and incubated in dilute buffer, show reduced triacylglycerol (TAG) synthesis, and accumulation stops after 24 h. Synthesis and accumulation can be maintained at high levels if the incubation medium contains abscisic acid (ABA) and/or a high osmotic concentration. Radiolabeled free fatty acids accumulate at higher levels in embryos that ...
PubMed:
9232885
PubMed Central:
PMC158399

59. Regulation of the cinnamate 4-hydroxylase (CYP73A1) in Jerusalem artichoke tubers in response to wounding and chemical treatments

Author:
Batard, Y.; Schalk, M.; Pierrel, M.A.; Zimmerlin, A.; Durst, F.; Werck-Reichhart, D.
Source:
Plant physiology 1997 v.113 no.3 pp. 951-959
ISSN:
0032-0889
Subject:
protein synthesis; dose response; phytochrome; genetic code; oxygenases; stress response; phenobarbital; cinnamic acid; tubers; gene expression; transcription (genetics); genes; clofibrate; enzyme activity; chemical treatment; benzopyrenes; Helianthus tuberosus
Abstract:
... trans-Cinnamate 4-hydroxylase (C4H) is a plant-specific cytochrome (P450) that is encoded by the gene CYPZ3A and catalyzes the second step of the multibranched phenylpropanoid pathway. Increases in C4H activity in response to physical and chemical stresses have been well documented, but the mechanism of these increases has never been studied in detail. This paper reports on the regulatory mechanis ...

60. Solubilization and separation of a plant plasma membrane NADPH-O2- synthase from other NAD(P)H oxidoreductases

Author:
Gestelen, P. van.; Asard, H.; Caubergs, R.J.
Source:
Plant physiology 1997 v.115 no.2 pp. 543-550
ISSN:
0032-0889
Subject:
quinacrine; dose response; seedlings; gas exchange; pyridines; Phaseolus vulgaris; peroxidases; cytochrome c; adenosinetriphosphatase; oxaloacetic acid; plasma membrane; imidazoles; solubility; oxygen; protein composition; cyanides
Abstract:
... Solubilization and ion-exchange chromatography of plasma membrane proteins obtained from bean (Phaseolus vulgaris L.) seedlingsresulted in a single NAD(P)H-O2(-)-synthase protein peak. This enzyme showed a high preference toward NADPH as a substrate (reaction rate, 27.4 nmol O2- produced min-1 mg-1 protein), whereas NADH reactions ranged from 0 to maximally 15% of the NADPH reactions. The protein ...

61. Sugar repression of mannitol dehydrogenase activity in celery cells

Author:
Prata, R.T.N.; Williamson, J.D.; Conkling, M.A.; Pharr, D.M.
Source:
Plant physiology 1997 v.114 no.1 pp. 307-314
ISSN:
0032-0889
Subject:
dose response; fructokinase; galactitol; galactose; enzyme activity; glucose; sorbitol; fructose; mannose; oxidoreductases; enzyme inhibitors; mannitol; glucokinase; cell suspension culture; Apium graveolens
Abstract:
... We present evidence that the activity of the mannitol-catabolizing enzyme mannitol dehydrogenase (MTD) is repressed by sugars in cultured celery (Apium graveolens L.) cells. Furthermore, this sugar repression appears to be mediated by hexokinases (HKs) in a manner comparable to the reported sugar repression of photosynthetic genes. Glucose (Glc)-grown cell cultures expressed little MTD activity du ...

62. Suppression of ripening-associated gene expression in tomato fruits subjected to a high CO2 concentration

Author:
Rothan, C.; Duret, S.; Chevalier, C.; Raymond, P.
Source:
Plant physiology 1997 v.114 no.1 pp. 255-263
ISSN:
0032-0889
Subject:
Solanum lycopersicum var. lycopersicum; ripening; gene expression; dose response; acidification; ethylene; biosynthesis; carbon dioxide
Abstract:
... High concentrations of CO2 block or delay the ripening of fruits. In this study we investigated the effects of high CO2 on ripening and on the expression of stress- and ripening-inducible genes in cherry tomato (Lycopersicon esculentum Mill.) fruit. Mature-greentomato fruits were submitted to a high CO2 concentration (20%) for 3 d and then transferred to air. These conditions effectively inhibited ...

63. Tris is a competitive inhibitor of K+ activation of the vacuolar H+-pumping pyrophosphatase

Author:
Gordon-Weeks, R.; Korenkov, V.D.; Steele, S.H.; Leigh, R.A.
Source:
Plant physiology 1997 v.114 no.3 pp. 901-905
ISSN:
0032-0889
Subject:
Vigna radiata; hypocotyls; vacuoles; potassium; proton pump; ion transport; pyrophosphatases; enzyme activity; kinetics; enzyme inhibitors; buffers; dose response; pH
Abstract:
... The effects of a range of commonly used pH buffers on the hydrolytic activity of the plant vacuolar H+-transporting inorganic pyrophosphatase (V-PPase) from mung bean (Vigna radiata L.) hypocotyls were tested. All of the buffers inhibited K+ stimulation of the V-PPase, and the degree of inhibition was dependent on the concentrations of both the buffer and K+. The effects were dependent on the orga ...

64. Xylem sap pH increase: a drought signal received at the apoplastic face of the guard cell that involves the suppression of saturable abscisic acid uptake by the epidermal symplast

Author:
Wilkinson, S.; Davies, W.J.
Source:
Plant physiology 1997 v.113 no.2 pp. 559-573
ISSN:
0032-0889
Subject:
guard cells; ion transport; drought; sap; shoots; turgor; dose response; leaves; symplast; stomatal movement; Commelina communis; translocation (plant physiology); phloem; water content; xylem; biosynthesis; stress response; pH; chemical constituents of plants; abscisic acid; leaf conductance
Abstract:
... Drought increased the pH of Commelina communis xylem sap from 6.1 to 6.7. Conductances of transpiring leaves were 50% lower in pH 7.0 than in pH 6.0 buffers, but bulk leaf abscisic acid (ABA) concentration and shoot water status were unaffected by pH. Stomatal apertures of isolated abaxial epidermis incubated on simple buffers increased with external pH, so in vivo this must be overridden by alter ...

65. The effect of Cu2+ on ion transport systems of the plant cell plasmalemma

Author:
Demidchik, V.; Sokolik, A.; Yurin, V.
Source:
Plant physiology 1997 v.114 no.4 pp. 1313-1325
ISSN:
0032-0889
Subject:
Nitella; copper; ion transport; potassium; chlorides; dose response; calcium; membrane permeability; adenosinetriphosphatase; enzyme activity; enzyme inhibitors; plasma membrane
Abstract:
... Changes in plasmalemma permeability caused by excessive Cu2+ levels were examined in cells of a freshwater alga (Nitella flexilis) using a conventional microelectrode voltage-clamp technique. A rapid Cu2+-induced increase of plasmalemma conductance starting from 5 micrometer Cu2+ was shown. Cu2+-induced plasmalemma conductance (ClGm) was nonselective and potential-independent, resembling the condu ...

66. A radial concentration gradient of indole-3-acetic acid is related to secondary xylem development in hybrid aspen

Author:
Tuominen, H.; Puech, L.; Fink, S.; Sundberg, B.
Source:
Plant physiology 1997 v.115 no.2 pp. 577-585
ISSN:
0032-0889
Subject:
gene transfer; plant development; hybrids; biosynthesis; dose response; stems; morphogenesis; cell growth; developmental stages; transgenic plants; genetic variation; Agrobacterium radiobacter; cell division; gene expression; Populus tremuloides; Populus tremula; cambium; xylem; indole acetic acid
Abstract:
... The radial distribution pattern of indole-3-acetic acid (IAA) was determined across the developing tissues of the cambial region in the stem of hybrid aspen (Populus tremula L. x Populus tremuloides Michx). IAA content was measured in consecutive tangential cryosections using a microscale mass spectrometry technique. Analysis was performed with wild-type and transgenic trees with an ectopic expres ...