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You searched for: Source 1997 v.114 no.2 Remove constraint Source: 1997 v.114 no.2 Subject dose response Remove constraint Subject: dose response
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1. 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 ...

2. 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 ...

3. 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 ...

4. 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 ...

5. 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 ...

6. 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 ...

7. 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

8. 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 ...

9. 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 ...