Photosynthetic carbon assimilation and associated metabolism in relation to water deficits in higher plants

Plant, Cell and Environment - Tập 25 Số 2 - Trang 275-294 - 2002
Debbie A. Lawlor1, Gabriel Cornic2
1Biochemistry and Physiology Department, IACR-Rothamsted, Harpenden, Herts, AL5 2JQ, UK and
2Laboratoire d’Ecophysiologie végétale, ESE, UPRESA 8079, Bât. 362, UFR scientifique d’Orsay, Université de Paris XI, F-91405, Orsay Cedex, France

Tóm tắt

SummaryExperimental studies on CO2 assimilation of mesophytic C3 plants in relation to relative water content (RWC) are discussed. Decreasing RWC slows the actual rate of photosynthetic CO2 assimilation (A) and decreases the potential rate (Apot). Generally, as RWC falls from c. 100 to c. 75%, the stomatal conductance (gs) decreases, and with it A. However, there are two general types of relation of Apot to RWC, which are called Type 1 and Type 2. Type 1 has two main phases. As RWC decreases from 100 to c. 75%, Apot is unaffected, but decreasing stomatal conductance (gs) results in smaller A, and lower CO2 concentration inside the leaf (Ci) and in the chloroplast (Cc), the latter falling possibly to the compensation point. Down‐regulation of electron transport occurs by energy quenching mechanisms, and changes in carbohydrate and nitrogen metabolism are considered acclimatory, caused by low Ci and reversible by elevated CO2. Below 75% RWC, there is metabolic inhibition of Apot, inhibition of A then being partly (but progressively less) reversible by elevated CO2; gs regulates A progressively less, and Ci and CO2 compensation point, Γ rise. It is suggested that this is the true stress phase, where the decrease in Apot is caused by decreased ATP synthesis and a consequent decreased synthesis of RuBP. In the Type 2 response, Apot decreases progressively at RWC 100 to 75%, with A being progressively less restored to the unstressed value by elevated CO2. Decreased gs leads to a lower Ci and Cc but they probably do not reach compensation point: gs becomes progressively less important and metabolic limitations more important as RWC falls. The primary effect of low RWC on Apot is most probably caused by limited RuBP synthesis, as a result of decreased ATP synthesis, either through inhibition of Coupling Factor activity or amount due to increased ion concentration. Carbohydrate synthesis and accumulation decrease. Type 2 response is considered equivalent to Type 1 at RWC below c. 75%, with Apot inhibited by limited ATP and RuBP synthesis, respiratory metabolism dominates and Ci and Γ rise. The importance of inhibited ATP synthesis as a primary cause of decreasing Apot is discussed. Factors determining the Type 1 and Type 2 responses are unknown. Electron transport is maintained (but down‐regulated) in Types 1 and 2 over a wide range of RWC, and a large reduced/oxidized adenylate ratio results. Metabolic imbalance results in amino acid accumulation and decreased and altered protein synthesis. These conditions profoundly affect cell functions and ultimately cause cell death. Type 1 and 2 responses may reflect differences in gs and in sensitivity of metabolism to decreasing RWC.

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Tài liệu tham khảo

10.1111/j.1365-3040.1988.tb01799.x

10.1146/annurev.arplant.36.1.27

10.1098/rstb.2000.0704

10.1104/pp.112.1.265

10.1093/jxb/48.7.1439

Bodribb T., 1996, Dynamics of changing intercellular CO2 concentration (ci) during drought and determination of minimum functional ci, Plant Physiology, 111, 179, 10.1104/pp.111.1.179

10.1104/pp.114.1.185

Boyer J.S., 1987, Photophosphorylation at low water potentials, Current Topics in Plant Biochemistry and Physiology, 6, 69

10.1007/BF00203643

10.1071/9780643103405

10.1071/PP9860669

10.1071/PP9910287

10.1093/jxb/43.12.1557

10.1093/jxb/42.1.1

Cornic G., 1994, Photoinhibition of Photosynthesis, 297

10.1016/S1360-1385(00)01625-3

10.1007/BF00197786

Cornic G., 1992, Leaf photosynthesis is resistant to a mild drought stress, Photosynthetica, 27, 295

10.1007/BF00392157

10.1007/0-306-48135-9_14

10.1111/j.1399-3054.1983.tb04184.x

De Kouchkovsky Y., 1992, Research in Photosynthesis, 709

10.1046/j.1365-313X.1993.04020215.x

10.1046/j.1365-3040.1999.00471.x

10.1007/BF00397337

10.1046/j.1365-3040.1999.00420.x

10.1016/0014-5793(90)80066-R

10.1071/PP99019

Evans L.T., 1998, Feeding the Ten Billion. Plants and Population Growth

10.1104/pp.117.1.293

10.1104/pp.121.2.675

10.1071/PP98054

10.1046/j.1365-3040.1999.00371.x

FlexasJ.&MedranoH.(2002)Drought‐inhibition of photosynthesis in C3 plants: stomatal and non‐stomatal limitations revisited.Annals of Botany89 in press.

10.1104/pp.117.1.283

10.1016/S0304-4165(89)80016-9

10.1104/pp.66.6.1032

10.1007/BF00196888

10.1104/pp.98.2.516

10.1007/BF00195891

10.1104/pp.98.2.660

10.1104/pp.103.2.629

10.1023/A:1006083802715

10.1034/j.1399-3054.2000.1100410.x

Haupt‐HertingS.&FockH.P.(2002)Oxygen exchange in relation to carbon assimilation in drought stressed leaves during photosynthesis.Annals of Butany in press.

10.1007/978-3-662-04064-5_4

10.1146/annurev.arplant.47.1.431

10.1104/pp.98.3.801

10.1111/j.1365-3040.1985.tb01227.x

10.1007/978-1-4615-6007-4

10.1111/j.1399-3054.1987.tb04631.x

10.1104/pp.96.2.363

10.1104/pp.91.3.970

10.1104/pp.53.3.474

10.1038/384557a0

Kramer P.J., 1995, Water Relation of Plants and Soils

10.1104/pp.98.4.1310

Lawlor D.W., 1976, Water stress induced changes in photosynthesis, photorespiration, respiration and CO2 compensation concentration of wheat, Photosynthetica, 10, 378

Lawlor D.W., 1995, Environment and Plant Metabolism, 129

Lawlor D.W., 2001, Photosynthesis

LawlorD.W.(2002)Limitation to photosynthesis in water stressed leaves: stomata versus metabolism and the role of ATP.Annals of Botany(in press).

10.1007/BF00388966

10.1093/jxb/28.2.320

10.1093/jxb/28.2.329

10.1007/978-94-017-4971-8_81

Lawlor D.W., 1991, Photosynthesis, Photoreactions to Plant Productivity, 421

10.1104/pp.100.2.733

10.1111/j.1744-7348.1997.tb05176.x

10.1007/BF00035944

10.1007/978-3-662-04064-5_7

10.1016/S1360-1385(00)01648-4

Ort D.R., 1994, Photoinhibition of Photosynthesis, 315

10.1104/pp.96.4.1018

10.1016/S1360-1385(97)80981-8

10.1111/j.1438-8677.1999.tb00272.x

10.1093/jexbot/50.330.127

ParryM.A.J. AndrolojcJ.P. KhanS. LeaP.J.&KeysA.J.(2002)Rubisco activity: efects of water stress.Annals of Botanyin press.

10.1046/j.1365-313X.1995.7040535.x

10.1046/j.1365-3040.1997.d01-89.x

Pospí silová J., 1997, Handbook of Photosynthesis, 427

10.1071/PP9950285

10.1111/j.1365-3040.1992.tb01455.x

10.1007/BF00392622

10.1007/BF02411393

10.1104/pp.89.3.762

10.1104/pp.117.4.1253

10.1104/pp.86.1.293

10.1093/jexbot/51.suppl_1.357

10.1007/BF00195191

10.1023/a:1005921127513

10.1007/BF00959528

Scheuermann R., 1991, Simultaneous gas exchange and fluorescence measure,ments indicate differences in the response of sunflower, bean and maize to water stress, Photosynthesis Research, 27, 189, 10.1007/BF00035840

10.1104/pp.117.4.1135

10.1007/BF00392810

10.1104/pp.78.1.71

Sharkey T.D., 1990, Water stress effects on photosynthesis, Photosynthetica, 24, 651

10.1007/BF00393725

10.1104/pp.89.4.1060

10.1104/pp.82.1.90

10.1105/tpc.7.7.821

10.1104/pp.92.4.1053

TangA.C. KawamitsaY. KanechiM.&BoyerJ.S.(2002)Photosynthesis at low water potential in leaf discs lacking epidermis.Annals of Botany(in press).

10.1007/BF00035537

10.1038/44842

10.1093/jxb/33.3.393

10.1007/BF00195717

10.1111/j.1399-3054.1991.tb01709.x

10.1104/pp.89.4.1066

10.1016/S0981-9428(00)80093-5

10.1016/S0065-2296(08)60124-X

10.1111/j.1365-3040.1990.tb01982.x

10.1104/pp.81.3.754

10.1016/0005-2728(79)90139-7

10.1111/j.1365-3040.1991.tb00963.x