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Plant Physiol. (1998) 117: 283-292 Drought-Induced Effects on Nitrate Reductase Activity and mRNA and on the Coordination of Nitrogen and Carbon Metabolism in Maize Leaves1
Department of Environmental Biology, Institute of Grassland and Environmental Research, Plas Gogerddan, Aberystwyth, Ceredigion SY23 3EB, United Kingdom (C.H.F.); Laboratoire du Metabolisme, Institut National de la Recherche Agronomique, Route de Saint Cyr, F-78026 Versailles, France (M.-H.V.); and Lehrstuhl für Genetik, Fakultät für Biolgie, Universität Bielefeld, Postfach 10 01 31, D-33501 Bielefeld, Germany (A.M., T.W.B.)
Maize (Zea mays L.)
plants were grown to the nine-leaf stage. Despite a saturating N
supply, the youngest mature leaves (seventh position on the stem)
contained little NO3
The assimilation of N in the leaves of higher plants requires both
energy and C skeletons. Triose phosphate produced in the leaves as a
result of photosynthetic C assimilation can be used for the synthesis
of either carbohydrates or ketoacids (e.g. 2-oxoglutarate) via the
anapleurotic pathway. 2-Oxoglutarate produced in the cytosol is
imported into the chloroplasts, where it may serve as the acceptor for
NH4+ during amino acid
synthesis. To meet the needs of growth and development for both
carbohydrates and amino acids, C partitioning is coordinated by a
sophisticated regulatory system. Many points of reciprocal control
exist between the pathways of C and N assimilation (Champigny and
Foyer, 1992 During prolonged periods of drought, the decrease in water availability
for transport-associated processes leads to changes in the
concentrations of many metabolites, followed by disturbances in amino
acid and carbohydrate metabolism. For example, there is an increase in
the synthesis of compatible solutes such as special amino acids (e.g.
Pro), sugars and sugar-alcohols, and Gly betaine (Yancey et al., 1982 Studies of the effects of drought on N acquisition have frequently
concerned phenomena associated with roots stressed either by the
addition of PEG (Talouizite and Champigny, 1988 The reduction of NO3 In situations of water deprivation, maximal foliar extractable NR
activity has been found to decrease in some cases (Plaut, 1974 SPS plays a pivotal role in Suc synthesis (Kerr and Huber, 1987 PEPCase catalyzes the carboxylation of PEP to oxaloacetate. This
cytosolic enzyme fixes HCO3 Maize (Zea mays L.) plants were grown individually in
10-L pots in a growth chamber with a 16-h photoperiod at 23°C
day/18°C night and 170 µmol photons m Photosynthesis Measurements and Sample Preparation
Isolation of RNA and Northern-Blot Analysis RNA was extracted from frozen leaf tissue as described by Verwoerd et al. (1989) . The isolated RNA was precipitated twice, each time with
4 m LiCl for 60 min at 0°C, to remove traces of DNA and
small RNA species. Electrophoretic separation of total denatured RNA
samples, transfer onto blotting membranes (Zeta Probe, Bio-Rad), and
hybridization with 32P-labeled cDNAs
corresponding to NR (Gowrie and Campbell, 1989), PEPCase (Sheen and
Bogorad, 1987), or SPS (Worrell et al., 1991) of maize were performed
as previously described (Migge et al., 1996). The signals
visible after autoradiography were quantified by phosphor imaging. In
all cases, three replicates were performed.
Enzyme Assays NR NR was extracted from leaf tissue that had been reduced to a fine powder in a mortar with liquid N. The extraction buffer (50 mm Mops-KOH, pH 7.8, 5 mm NaF, 1 µm Na2MoO4, 10 µm FAD, 1 µm leupeptin, 1 µm microcystin, 0.2 g 1 fresh
weight PVP, 2 mm  -mercaptoethanol, and 5 mm
EDTA) was then added to the leaf tissue powder (1 mL 50 mg1 fresh weight). The homogenate was
centrifuged at 4°C for 5 min at 12,000g. NR activity was
measured immediately in the supernatant. The reaction mixture consisted
of 50 mm Mops-KOH buffer, pH 7.5, supplemented with 1 mm NaF, 10 mm KNO3, 0.17 mm NADH, and either 10 mm
MgCl2 or 5 mm EDTA. The reaction was
terminated after 8 or 16 min by the addition of an equal volume of
sulfanilamide (1% [w/v] in 3 n HCl) and then
naphthylethylene-diamine dihydrochloride (0.02% [w/v]) to the
reaction mixture, and the A540 was
measured. The activation state of NR is defined as the activity
measured in the presence of 10 mm
MgCl2 divided by the activity measured in the
presence of 5 mm EDTA (expressed as a percentage).
SPS Frozen leaf material was ground in a mortar with liquid N in a medium (250 mg fresh weight mL1) containing 100 mm Tricine buffer, pH 7.5, and 200 mm KCl, 5 mm DTT, 4% (w/v) insoluble PVP, 0.33 mm PMSF,
6 µm leupeptin, 0.6 mm N-ethyl maleimide, and
1.3 mm EDTA. The homogenate was centrifuged at
12,000g for 5 min and the supernatant was desalted using
a Sephadex G-25 column (PD10, Pharmacia). The proteins were eluted with
100 mm Tricine buffer, pH 7.5, containing 200 mm KCl and 5 mm DTT. SPS activity was
determined under Vmax conditions or under
conditions of limiting substrates in the presence of Pi
(Vsel). The Vmax
assay medium consisted of 50 mm Mops-NaOH buffer, pH 7.5, 15 mm MgCl2, 1 mm DTT, 10 mm Fru-6-P, 10 mm UDP-Glc, and 40 mm Glc-6-P. The Vsel assay was
similar to this except that the concentrations of Fru-6-P, UDP-Glc, and
Glc-6-P were 2, 6, and 6 mm, respectively, and 5 mm Pi was added to the assay medium. All reactions were
incubated at 25°C for 15 min and then stopped by the addition of 7.5 m NaOH, 1/1, v/v). Unreacted Fru-6-P was destroyed by
boiling for 10 min. After the assay mixture was cooled, anthrone
(0.14% [w/v] in 13.8 n H2SO4)
was added and the sample was incubated at 40°C for a further 20 min.
The A620 was then measured.
PEPCase Leaf tissue was ground in liquid N in a medium containing 100 mm Tris-HCl, pH 8.0, 10 mm MgCl2, 20% (v/v) glycerol, 5 mm DTT, 5 mm NaF, 1 mm PMSF, 1 µm microcystin, 20 µm leupeptin, 16 µm chymostatin, and 2% (w/v) PVP. Extracts were centrifuged at 4°C for 15 min at 15,000 rpm and desalted rapidly on Sephadex G-25. The reaction medium consisted of 50 mm Hepes-KOH, pH 7.3, 5 mm MgCl2, 1 mm NaHCO3, 5 mm NaF, 0.2 mm NADH, 10 units of malate dehydrogenase (Boehringer Mannheim), and 3 mm PEP in a final volume of 1 mL. Control cuvettes were without PEP. The reaction was followed at A340 in cuvettes maintained at 30°C. Malate sensitivity was determined by the addition of 0.8 mm malate to both the sample and control cuvettes.Carbohydrate Analysis Lyophilized leaf material was ground in a mortar with 1 m HClO4 (5-10 mg dry weight mL1), and the extract was centrifuged at
12,000g for 5 min. The supernatant was used for the
determination of soluble sugars (hexose and Suc), and the pellet was
used for the estimation of the starch content. An aliquot of the
supernatant fraction (500 µL) was neutralized by adding 200 µL of
0.5 m Tris-HCl, pH 7.5, and 60 µL of 5 m
K2CO3. The precipitate from
this reaction was removed by centrifugation at 12,000g for 5 min. Glc, Fru, and Suc in the soluble fraction were analyzed
enzymatically as described by Galtier et al. (1995). The pellet
reserved for starch determination was resuspended in water and
incubated at 100°C for 2 h. Glc was then released by incubation
at 50°C for 3 h in 20 mm sodium acetate buffer, pH 4.6, with amylase (0.66 units mL1) and
amyloglucosidase (15 units mL1; both enzymes
from Boehringer Mannheim) and assayed enzymatically as described above.
Amino Acid Analysis Amino acids were extracted from lyophilized leaf material in 2% (w/v) 5-sulfosalicylic acid (10 mg dry weight mL1). The extract was centrifuged at
12,000g for 5 min, and the supernatant was assayed for total
amino acids by the Rosen colorimetric method with Leu as the reference.
An aliquot of the supernatant was used to determine amino acid
composition by ion-exchange chromatography (model LC5001 analyzer,
Biotronics, Lowell, MA; Rochat and Boutin, 1989); physiological program
run with lithium citrate buffers and detection at
A570 and A440
after postcolumn derivatization with ninhydrin (Rochat and Boutin,
1989).
Determination of NO3 , protein, and
chlorophyll were analyzed using the same leaf extracts as for NR
activity. NO3 was determined
by the method of Cataldo et al. (1975), soluble protein was determined
by the method of Bradford (1976), and chlorophyll was determined by the
method of Arnon (1949).
Total Leaf Water Potential and Photosynthesis The total leaf water potential in well-watered control plants ( 0.5 MPa) was constant throughout the period of the experiment (Fig.
1). In contrast, the total leaf water
potential of the leaves of the droughted plants measured 3 h into
the photoperiod decreased sharply after 3 d of water deprivation
(Fig. 1). The rates of photosynthetic CO2
assimilation increased in well-watered plants over the first 3 d
of the experiment, whereas photosynthesis was constant over this period
in plants deprived of water (Fig. 2). At
the point of measurement (3 h into the photoperiod) total leaf water
potential was similar in leaves of all plants for the first 3 d of
the experiment; therefore, it is not surprising that the measured rates
of photosynthesis did not decline over this period. Nevertheless,
photosynthesis in well-watered and droughted plants varied by a factor
of 2 at d 3 of the experiment. Once the total leaf water potential
decreased (from d 4 of water deprivation onward), there was a
concomitant substantial (approximately 50%) loss of
CO2 assimilation capacity in the droughted leaves
(Fig. 2). Photosynthetic CO2 assimilation was
comparable in all plants when water was resupplied to the droughted
plants on d 3 of the experiment (Fig. 2).
NR Activity Total extractable foliar NR activity decreased as a result of water stress (Fig. 3A). Less than 10% of the original maximal NR activity remained after 7 d of water deprivation. NR activity extracted and assayed in the presence of Mg2+ (Fig. 3D) and compared with the total activity extracted and assayed in the presence of EDTA (Fig. 3A) gives an indication of the activation state of the enzyme (Kaiser et al., 1993; Huber et al., 1996b). NR was about 60% activated in
water-replete leaves harvested 3 h into the photoperiod
(Fig. 3D). The NR activation state decreased in droughted leaves
compared with well-watered controls. The values of NR activity were
very low in the presence of the inhibitor Mg2+,
causing considerable variation in calculated values for NR activation state (Fig. 3D). Maximal extractable NR activity recovered rapidly when
water was restored at d 3 of the experiment (Fig.
4). There was a clear relationship
between total extractable NR activity and the rate of
photosynthetic CO2 assimilation such
that the inhibition of photosynthesis caused by water stress
correlated with a marked decrease in total NR activity
(r2 = 0.832; Fig.
5).
PEPCase and SPS Activities The maximal catalytic activity of PEPCase significantly increased in water-stressed maize leaves compared with well-watered controls (Fig. 3B). At the same time, the sensitivity to the inhibitor malate was decreased in droughted plants compared with the water-replete controls (Fig. 3E). Total extractable SPS activity decreased in droughted leaves compared with the well-watered controls (Fig. 3C), and there was a concomitant increase in the sensitivity of the enzyme to the inhibitor Pi (Fig. 3F).Transcript Levels NR transcript abundance rapidly decreased following the imposition of water stress (Fig. 6). After 7 d of water deprivation, NR mRNA was about 80% lower than in water-replete plants (Fig. 6B); however, the NR mRNA pool was restored within 24 h after droughted plants were rehydrated after 3 d (Fig. 6B). In contrast to the severe drought-induced decrease in NR mRNA, SPS and PEPCase transcripts were much less affected (Fig. 6, A and C). PEPCase transcripts decreased by about 30% after 7 d of water stress (Fig. 6A), whereas the effect on the SPS mRNA pool was even less severe (10-20%; Fig. 6C). In both cases the levels of transcript were rapidly restored to control values following rehydration at d 3 of the experiment.
Foliar Carbohydrate Contents The Suc contents of leaves from water-stressed and well-watered maize plants were similar throughout the 7 d of the experiment (Table I). In contrast, foliar Fru and Glc contents increased by 3.7- and 6-fold, respectively, in the leaves of plants deprived of water for 7 d (Table I) compared with the water-replete plants (Table I). There was about twice the amount of starch in leaves of maize plants deprived of water for 7 d than in well-watered controls (Table I). When water was restored to droughted plants at d 3 of the experiments, the foliar carbohydrate contents rapidly returned to values comparable to those measured in water-replete controls (data not shown).
Foliar Amino Acid and NO3 1 chlorophyll at
the beginning of the experiment to about 9 µmol mg1 chlorophyll after 7 d of water stress.
Gln, Glu, Asn, Gly, and Ser accounted for a large part of the total
amino acid pool in water-replete maize plants (Fig.
7). The foliar contents of Gln, Glu, and
Asn were not greatly changed in leaves of plants deprived of water, but
there was a marked accumulation of Ala (Fig. 7). Small increases in
other amino acids were also observed (data not shown). The increase in
the total amino acid pool of leaves of water-stressed plants was
therefore due to the accumulation of Ala. The maize plants studied in
these experiments were large but contained little stored
NO3 in their leaves despite
being supplied with saturating N throughout the period of growth and
development (Khamis and Lamaze, 1990; Khamis et al., 1990). In
water-stressed maize leaves, foliar
NO3 levels decreased below the
level of detection (Table I).
Drought induces complex changes in C and N metabolism resulting
from water deficits and from modifications in the availability of
nutrients (Talouizite and Champigny, 1988
* Corresponding author; e-mail christine.foyer{at}bbsrc.ac.uk; fax 44-1970-828357. Received August 20, 1997;
accepted February 2, 1998.
Abbreviations: NR, nitrate reductase. PEPCase, phosphoenolpyruvate carboxylase. SPS, Suc phosphate synthase.
The authors are grateful to Dr. Wilbur Campbell (Michigan Technological University, Houghton) for providing the cDNA clone encoding maize NR and to Dr. Lawrence Bogorad (Harvard University, Cambridge, MA) for sending us a cDNA clone corresponding to maize PEPCase. T.W.B. wishes to thank Professor Alfred Pühler (Universtität Bielefeld, Germany) for the opportunity to work at the Lehrstuhl für Genetik.
Arnon DI (1949) Plant Physiol 34: 1-15 Bakrim N, Peril J-L, Helen E, Rocker J-PK, Arrio-Dupont M, Vidal J, Gadal P, Chollet R (1993) Regulatory phosphorylation of C4 phosphoenolpyruvate carboxylase: a cardinal event influencing the photosynthesis rate in Sorghum and maize. Plant Physiol 101: 891-897 [Abstract] Becker TW, Foyer CH, Caboche M (1992) Light regulated expression of the nitrate-reductase and nitrite-reductase genes in tomato and in the phytochrome-deficient aurea mutant of tomato. Planta 188: 39-47 [CrossRef] Beyrouty CA, Grigg BC, Norman RJ, Wells BR (1994) Nutrient uptake by rice in response to water management. J Plant Nutr 17: 39-55 Bradford MM (1976) A rapid and sensitive method for the quantitation of microgram quantities of protein utilising the principle of protein-dye binding. Anal Biochem 72: 248-254 [CrossRef][Web of Science][Medline] Brewitz E, Larsson C-M, Larsson M (1996) Responses of nitrate assimilation and N translocation in tomato (Lycopersicon esculentum Mill) to reduced ambient air humidity. J Exp Bot 47: 855-861 Cataldo DA, Haroon M, Schrader LE, Yougs VL (1975) Rapid colorimetric determination of nitrate in plant tissue by nitration of salicylic acid. Commum Soil Sci and Plant Analysis 6: 71-80
Champigny M-L,
Foyer CH
(1992)
Nitrate activation of cytosolic protein kinases diverts photosynthetic carbon from sucrose to amino acid biosynthesis.
Plant Physiol
100:
7-12
Chaves M,
Pereira J
(1992)
Water stress, CO2 and climate change.
J Exp Bot
43:
1131-1139
Chazen O, Neumann PM (1994) Hydraulic signals from the roots and rapid cell-wall hardening in growing maize (Zea maize L.) leaves are primary responses to polyethylene glycol-induced water deficits. Plant Physiol 104: 1385-1392 [Abstract]
Cheng CL,
Acedo GN,
Christinsin M,
Conkling MA
(1992)
Sucrose mimics the light induction of Arabidopsis nitrate reductase gene transcription.
Proc Natl Acad Sci USA
89:
1861-1864
Cheng CL,
Dewdney J,
Kleinhofs A,
Goodman HM
(1986)
Cloning and nitrate induction of nitrate reductase mRNA.
Proc Natl Acad Sci USA
83:
6825-6826
Coïc Y, Lesaint C (1975) Alsace 23: 1-22 Cornic G, Le Gouallec JL, Briantais JM, Hodges M (1989) Effect of dehydration and high light on photosynthesis of two C3 plants (Phaseolus vulgaris L.) and (Elatostema repens [Lour], Hall f). Planta 177: 84-90 [CrossRef] Davies WJ, Tardieu F, Trejo CL (1994) How do chemical signals work in plants that grow in drying soil? Plant Physiol 104: 309-314 [Web of Science][Medline]
Doehlert DC,
Huber SC
(1983)
Regulation of spinach leaf sucrose-phosphate synthase by glucose 6-phosphate, inorganic phosphate and pH.
Plant Physiol
73:
989-994
Fambrini M,
Pugliesi C,
Vernieri P,
Pardossi A,
Baroncelli S
(1994)
Characterization of a wilty sunflower (Helianthus annuus L.) mutant. II. Water relations, stomatal conductance, abscisic acid content in leaves and xylem sap of plants subjected to water deficiency.
J Exp Bot
45:
1809-1815
Ferrario-Méry S,
Valadier M-H,
Foyer CH
(1998)
Overexpression of nitrate reductase in tobacco delays drought-induced decreases in nitrate reductase activity and mRNA.
Plant Physiol
117:
293-302
Ferrario S, Valadier M-H, Morot-Gaudry J-F, Foyer CH (1995) Effects of constitutive expression of nitrate reductase in transgenic Nicotiana plumbaginifolia L. in response to varying nitrogen supply. Planta 196: 288-294 Fox TC, Geiger DR (1985) Osmotic response of sugar beet leaves at CO2 compensation point. Plant Physiol 80: 239-241 Foyer CH, Champigny ML, Valadier MH, Ferrario S (1996) Partitioning of photosynthetic carbon: the role of nitrate activation of protein kinases. In P Shewry, N Halford, R Hooley, eds, Protein Phosphorylation in Plants. Proceedings of the Phytochemical Society of Europe. Clarendon Press, Oxford, UK, pp 35-51 Foyer CH, Galtier N (1996) Source-sink interaction and communication in leaves. In E Zamski, AA Schafer, eds, Photoassimilate Distribution in Plants and Crops: Source Sink Relationships. Marcel Dekker, Inc., pp 311-340 Foyer CH, Valadier MH, Ferrario S (1994) Co-regulation of nitrogen and carbon assimilation in leaves. In N Smirnoff, eds, Environment and Plant Metabolism, Flexibility and Acclimation. Bios Scientific Publishers, Guildford, UK, pp 17-33 Furbank RT, Stitt M, Foyer CH (1985) Intercellular compartmentation of sucrose synthesis in leaves of Zea mays. Planta 163: 172-178
Galangau F,
Daniel-Vedel F,
Moureaux T,
Dorbe MF,
Leydecker MT,
Caboche M
(1988)
Expression of leaf nitrate reductase genes from tomato and tobacco in relation to light-dark regimes and nitrate supply.
Plant Physiol
88:
383-388
Galtier N, Foyer CH, Murchie E, Alred R, Quick P, Voelker TA, Thepenier C, Lasceve G, Betsche T (1995) Effects of light and atmosphere CO2 enrichment on photosynthetic carbon partitioning and carbon/nitrogen ratios in tomato (Lycopersicon esculentum L.) plants over-expressing sucrose phosphate synthase. J Exp Bot 46: 1335-1344 Girousse C, Bournitrateville R, Bonnemain J-L (1996) Water deficit-induced changes in concentration in proline and some other amino acids in the phloem sap of alfalfa. Plant Physiol 111: 109-113 [Abstract] Glaab J, Kaiser WM (1995) Inactivation of nitrate reductase is a two-step mechanism involving NR-protein phosphorylation and subsequent `binding' of an inhibitor protein. Planta 195: 514-518
Gowrie G,
Campbell WH
(1989)
cDNA clones for corn leaf NADH: nitrate reductase and chloroplast NAD(P)+ glyceraldehyde-3-phosphate dehydrogenase.
Plant Physiol
90:
792-798
Graham IA (1996) Carbohydrate control of gene expression in higher plants. Res Microbiol 147: 435-594 Heckathorn SA, De Lucia EH, Zielinski RE (1997) The contribution of drought-related decreases in foliar nitrogen concentration to decreases in photosynthetic capacity during and after drought in prairie grasses. Physiol Plant 101: 173-182 [CrossRef] Hesse H, Sonnewald U, Willmitzer L (1995) Cloning and expression analysis of sucrose phosphate synthase from sugar beet (Beta vulgaris L.). Mol Gen Genet 195: 514-518 Heuer B, Plaut Z, Federman E (1979) Nitrate and nitrite reduction in wheat leaves as affected by different types of water stress. Physiol Plant 46: 318-323
Huber JL,
Huber SC,
Campbell WH,
Redinbaugh MG
(1992a)
Comparative studies of the light modulation of nitrate reductase and sucrose-phosphate synthase activities in spinach leaves.
Plant Physiol
100:
706-712
Huber JL, Huber SC, Campbell WH, Redinbaugh MG (1992b) Reversible light/dark modulation of spinach leaf nitrate reductase activity involves protein phosphorylation. Arch Biochem Biophys 296: 58-65 [CrossRef][Web of Science][Medline] Huber JL, Redinbaugh MG, Huber SC, Campbell WH (1994a) Regulation of maize leaf nitrate reductase activity involves both gene expression and protein phosphorylation. Plant Physiol 106: 1667-1674 [Abstract] Huber SC, Bachmann M, Huber JL (1996a) Post-translational regulation of nitrate reductase activity: a role for Ca2+ and 14-3-3 proteins. Trend Plant Sci 1: 432-438 [CrossRef] Huber SC, Huber JL (1990) Regulation of spinach leaf sucrose-phosphate synthase by multisite phosphorylation. Curr Top Plant Biochem Physiol 9: 329-343 Huber SC, Huber JL, McMichael RW (1994b) Control of plant enzyme activity by reversible protein phosphorylation. Int Rev Cytol 149: 47-98 Huber SC, McMichael RW, Bachmann M, Huber JL, Shannon JC, Kang KK, Paul M (1996b) Regulation of leaf sucrose-phosphate synthase and nitrate reductase by reversible protein phosphorylation. In PR Shewry, NG Halford, R Hooley, eds, Protein Phosphorylation in Plants. Proceedings of the Phytochemical Society of Europe. Oxford Science Publications, Clarendon Press, Oxford, UK, pp 19-34 Huppe HC, Turpin DH (1994) Integration of carbon and nitrogen metabolism in plant and algal cells. Annu Rev Plant Physiol Plant Mol Biol 45: 577-607 [Web of Science]
Jiao J-A,
Chollet R
(1991)
Post-translational regulation of phosphoenolpyruvate carboxylase in C4 and crassulacean acid metabolism plants.
Plant Physiol
95:
981-985
Kaiser WM,
Brendle-Behnisch E
(1991)
Rapid modulation of spinach leaf nitrate reductase by photosynthesis. I. Modulation in vivo by CO2 availability.
Plant Physiol
96:
363-367
Kaiser WM,
Forster J
(1989)
Low CO2 prevents nitrate reduction in leaves.
Plant Physiol
91:
970-974
Kaiser WM, Spill D, Glaab J (1993) Rapid modulation of nitrate reductase in leaves and roots: indirect evidence for the involvement of protein phosphorylation/dephosphorylation. Physiol Plant 89: 557-562 [CrossRef] Kerr PS, Huber SC (1987) Co-ordinate control of sucrose formation in soybean leaves by sucrose phosphate synthase and fructose-2,6-bisphosphate. Planta 170: 197-204
Khamis S,
Lamaze T
(1990)
Maximal biomass production can occur in corn (Zea mays) in the absence of NO3
Khamis S,
Lamaze T,
Lemoine Y,
Foyer CH
(1990)
Adaptation of the photosynthetic apparatus in maize leaves as a result of nitrogen limitation.
Plant Physiol
94:
1436-1443
Klein R, Crafts-Brandner S, Salvucci M (1993) Cloning and development expression of the sucrose phosphate synthase gene from spinach. Planta 190: 498-510 [Medline] Koch KE (1996) Carbohydrate-modulated gene expression in plants. Annu Rev Plant Physiol Plant Mol Biol 47: 509-510 [CrossRef][Web of Science] Krapp A, Hofmann B, Schafer C, Stitt M (1993) Regulation of the expression of rbcS and other photosynthetic genes by carbohydrates: a mechanism for the "sink-regulation" of photosynthesis? Plant J 3: 817-828 Krapp A, Stitt M (1995) An evaluation of direct and indirect mechanisms for the "sink-regulation" of photosynthesis in spinach: changes in gas exchange, carbohydrates, metabolites, enzyme activities and steady-state transcript levels after cold-girdling source leaves. Planta 195: 313-323 [Web of Science] Larsson C-M, Larsson M, Purves JV, Clarkson DT (1991) Translocation and cycling through roots of recently absorbed nitrogen and sulphur in Triticum aestivum during vegetative and generative growth. Physiol Plant 82: 345-352 [CrossRef]
Larsson M,
Larsson C-M,
Whitford PN,
Clarkson DT
(1989)
Influence of osmotic stress on nitrate reductase activity in wheat (Triticum aestivum L.) and the role of abscisic acid.
J Exp Bot
40:
1265-1271
Lunn JE,
Furbank RT,
Hatch MD
(1997)
Adenosine 5 MacKintosh C, Douglas P, Lillo C (1995) Identification of a protein that inhibits the phosphorylation form of nitrate reductase from spinach (Spinacia oleracea) leaves. Plant Physiol 107: 451-457 [Abstract]
Melzer E,
O'Leary M
(1987)
Anapleurotic fixation by phosphoenolpyruvate carboxylase in C3 plants.
Plant Physiol
84:
58-60
Migge A, Meya G, Carrayol E, Hirel B, Becker TW (1996) Regulation of the subunit composition of tomato plastidic glutamine synthetase by light and the nitrogen source. Planta 200: 213-220 Nonami H, Boyer JS (1990) Primary events regulating stem growth at low water potentials. Plant Physiol 94: 1601-1609 Nussaume L, Vincentz M, Meyer C, Boutin JP, Caboche M (1995) Post-transcriptional regulation of nitrate reductase by light is abolished by an N-terminal deletion. Plant Cell 7: 611-621 [Abstract] Plaut Z (1974) Nitrate reductase activity of wheat seedlings during exposure to and recovery from water stress and salinity. Physiol Plant 30: 212-217 Quick WP, Siegl G, Neuhaus HE, Feil R, Stitt M (1989) Short-term water stress leads to a stimulation of sucrose synthesis by activating sucrose phosphate synthase. Planta 177: 536-546 Rochat C, Boutin J-P (1989) Carbohydrates and nitrogenous compounds changes in the hull and in the seed during the pod development of pea. Plant Physiol Biochem 27: 881-887 Saccardy K, Cornic G, Brulfert J, Reyss A (1996) Effect of drought stress on net CO2 uptake by Zea leaves. Planta 199: 589-595 [Web of Science] Scheible W-R, Gonzàlez-Fontes A, Lauerer M, Müller-Rober B, Caboche M, Stitt M (1997a) Nitrate acts as a signal to induce organic acid metabolism and repress starch metabolism in tobacco. Plant Cell 9: 783-98 [Abstract] Scheible W-R, Lauerer M, Schulz E-D, Caboche M, Stitt M (1997b) Accumulation of nitrate in the shoot acts as a signal to regulate shoot-root allocation in tobacco. Plant J 11: 671-91 [CrossRef]
Sheen J
(1989)
Metabolic repression of transcription in higher plants.
Plant Cell
2:
1027-1038
Sheen J (1994) Feedback control of gene expression. Photosynth Res 39: 427-438 Sheen J, Bogorad L (1987) Regulation of levels of nuclear transcripts for C4 photosynthesis in bundle sheath and mesophyll cells of maize leaves. Plant Mol Biol 4: 227-238 Siegl G, Mackintosh C, Stitt M (1990) Sucrose-phosphate synthase is dephosphorylated by protein photophatase 2A in spinach leaves. Evidence from the effects of okadaic acid and microcystin. FEBS Letts 270: 198-202 [CrossRef][Web of Science][Medline] Talouizite A, Champigny ML (1988) Response of wheat seedlings to short-term drought with particular respect to nitrate utilization. Plant Cell Environ 11: 149-155
Van Quy L,
Champigny ML
(1992)
Nitrate enhances the kinase activity for phosphorylation of phosphoenolpyruvate carboxylase and sucrose phosphate synthase proteins in wheat leaves.
Plant Physiol
99:
344-347
Verwoerd TC,
Dekker BM,
Hoekma A
(1989)
A small-scale procedure for the rapid isolation of plant RNAs.
Nucleic Acids Res
17:
2362
Vincentz M, Moureaux T, Leydecker MT, Vaucheret H, Caboche M (1993) Regulation of nitrate and nitrite reductase expression in Nicotiana plumbaginifolia leaves by nitrogen and carbon metabolites. Plant J 3: 315-324 [CrossRef][Web of Science][Medline] Wellburn FAM, Lau K-K, Milling PMK, Wellburn AR (1996) Drought and air pollution affect nitrogen cycling and free radical scavenging in Pinus halepensis (Mill). J Exp Bot 47: 1361-1367
Worrell AC,
Bruneau JM,
Summerfelt K,
Boersig M,
Voelker TA
(1991)
Expression of maize sucrose phosphate synthase in tomato alters leaf carbohydrate partitioning.
Plant Cell
3:
1121-1130
Yancey PH,
Clark ME,
Hand SC,
Bowlus RD,
Somero CN
(1982)
Living with water stress: evolution of osmolyte system.
Science
217:
1214-1222
Zrenner R, Stitt M (1991) Comparison of the effect of rapidly and gradually developing water stress on carbohydrate metabolism in spinach leaves. Plant Cell Envriron 14: 939-946
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  H. Bae, R. C. Sicher, M. S. Kim, S.-H. Kim, M. D. Strem, R. L. Melnick, and B. A. Bailey The beneficial endophyte Trichoderma hamatum isolate DIS 219b promotes growth and delays the onset of the drought response in Theobroma cacao J. Exp. Bot., June 29, 2009; (2009) erp165v1. [Abstract] [Full Text] [PDF]
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 O. Ghannoum C4 photosynthesis and water stress Ann. Bot., February 1, 2009; 103(4): 635 - 644. [Abstract] [Full Text] [PDF]
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O. K. Atkin and D. Macherel The crucial role of plant mitochondria in orchestrating drought tolerance Ann. Bot., February 1, 2009; 103(4): 581 - 597. [Abstract] [Full Text] [PDF]
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D. Moreau, A.-S. Voisin, C. Salon, and N. Munier-Jolain The model symbiotic association between Medicago truncatula cv. Jemalong and Rhizobium meliloti strain 2011 leads to N-stressed plants when symbiotic N2 fixation is the main N source for plant growth J. Exp. Bot., October 1, 2008; 59(13): 3509 - 3522. [Abstract] [Full Text] [PDF]
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A. Whittaker, T. Martinelli, J. M. Farrant, A. Bochicchio, and C. Vazzana Sucrose phosphate synthase activity and the co-ordination of carbon partitioning during sucrose and amino acid accumulation in desiccation-tolerant leaf material of the C4 resurrection plant Sporobolus stapfianus during dehydration J. Exp. Bot., October 1, 2007; 58(13): 3775 - 3787. [Abstract] [Full Text] [PDF]
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C. Fresneau, J. Ghashghaie, and G. Cornic Drought effect on nitrate reductase and sucrose-phosphate synthase activities in wheat (Triticum durum L.): role of leaf internal CO2 J. Exp. Bot., August 30, 2007; (2007) erm150v1. [Abstract] [Full Text] [PDF]
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M. Debouba, H. Maaroufi-Dghimi, A. Suzuki, M. H. Ghorbel, and H. Gouia Changes in Growth and Activity of Enzymes Involved in Nitrate Reduction and Ammonium Assimilation in Tomato Seedlings in Response to NaCl Stress Ann. Bot., June 1, 2007; 99(6): 1143 - 1151. [Abstract] [Full Text] [PDF]
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E. Urbanczyk-Wochniak and A. R. Fernie Metabolic profiling reveals altered nitrogen nutrient regimes have diverse effects on the metabolism of hydroponically-grown tomato (Solanum lycopersicum) plants J. Exp. Bot., January 1, 2005; 56(410): 309 - 321. [Abstract] [Full Text] [PDF]
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K. Kato, Y. Okamura, K. Kanahama, and Y. Kanayama Nitrate-independent expression of plant nitrate reductase in Lotus japonicus root nodules J. Exp. Bot., July 1, 2003; 54(388): 1685 - 1690. [Abstract] [Full Text] [PDF]
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E. A. BRAY Classification of Genes Differentially Expressed during Water-deficit Stress in Arabidopsis thaliana: an Analysis using Microarray and Differential Expression Data Ann. Bot., June 15, 2002; 89(7): 803 - 811. [Abstract] [Full Text] [PDF]
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S. Ferrario-Méry, M.-H. Valadier, and C. H. Foyer Overexpression of Nitrate Reductase in Tobacco Delays Drought-Induced Decreases in Nitrate Reductase Activity and mRNA Plant Physiology, May 1, 1998; 117(1): 293 - 302. [Abstract] [Full Text]
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Abstract
Introduction
) or subjected to 8 d of water
deprivation (
). The water potential of detached leaves was measured
with a Scholander pressure chamber. Each given value represents the
mean of three replicates. se is indicated for each value.
). Each value represents the mean of
three replicate experiments. se is indicated for each value.
). Each value represents the mean of three replicate
experiments. Chl, Chlorophyll.
-triphosphate-mediated activation of sucrose-phosphate synthase in bundle sheath cells of C4 plants.
Planta
202:
249-256