of chloroplasts were decreased under salt treatments. Both salinity and alkalinity reduced

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EFFECT OF SALINITY AND ALKALINITY ON CHLOROPLAST METABOLISM AND MINERAL CONSTITUENTSl

M. SANJIVA RImDy2 and V. S. R. DAS

Department of Botany, Srivenkateswara University, Tirupati (A.P.)

Received on March 31, 1978

SUMMARY

The chloroplast metabolism of peanut (Arachis hypogaea, L) plants grown in nor­ mal, salinized (NaCl) and alkalized (Na2COs) soils was investigated. Sodium and chloride contents were increased in chloroplasts with the sodium chloride treatment while sodium alone was increased with sodium carbonate treatment. The rates of photochemical reac­ tions viz., Hill reaction activity, photophosphorylation and NADP reducing activity of chloroplast ferredoxin were affected under salt stress. In general, the levels of reducing sugars and starch of chloroplasts were decreased while those of non-reducing sugars were increased by treatment with the salts. Total carbohydrate (Starch+total sugars) contents of chloroplasts were decreased under salt treatments. Both salinity and alkalinity reduced protein nitrogen with a concomitant increase in soluble nitrogen of chloroplasts. Mineral

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constituents like phosphorus, magnesium, manganese and iron of chloroplasts were also depressed by both the salts.

INTRODUCTION

Ramamoorthy (1968) estimated that out of 130.55 million hectares of cultivable land in India, 14.30 miUionhectares are alkaline and 10.91 million hectares are saline. Russel (1950) pointed out that the general effect of a high salt content in the soil is to give a dwarfed stunted plant and yield can be reduced over 20 per cent without salt damage being apparant to farmers.

Higher photosynthetic rates were observed on leaf area basis in salt treated plants of alfalfa and tomato compared to control plants (Kling, 1954). Salt tolerance was asso­ ciated with high rates of photosynthesis (Shakhov, 1956). The observations of Gale et al. (1967) on cotton show that salinity reduced the rate of photosynthesis, particularly photo­ chemical reactions of isolated chloroplasts. Most of the observations of earlier workers were confined to intact plan ts. In view of the above reports, the present investigation was made to understand the chloroplast metabolism of peaunt plants as affected by salt stress.

J. The data incorporated in this article fonned a part of Ph.D. thesis of the first author. 2. Present Address : Scientist-l (Physiology), Sugarcane Breeding Institute, Coimbatore-7

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266

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M. SANJIVA REDDY AND V.S.R. DAS

MATERIAL AND MB'f.HODS

Peanut plants (Arachis hypogaea, L) variety TMV-2 were raised in earthen Pots (12" x 12") containing a mixture of soil and compost (3:1). After about 10 days from sowing, tbe plants were thinned to three per pan. Salt treatments were applied at tbe 15th day after sowing by adding sodium chloride for inducing salinity and sodium carbonate for inducing alkalinity. The salts were added in the form of solution to raise the salt con­ tent of the soil to 0.4 per cent with sodium chloride and 0.2 per cent with sodium car­ bonate based on dry weight of soil. A set of controls were maintained by adding tap water in place of the salt solutions. At 30th day after sowing the salt treatments were given second time with the same concentration. Soil moisture was maintained between 50 and 100 per cent field capacity. Leaf samples were collected for chloroplast isolation after 7, 15, 22 and 30 days of the first salt treatment.

Chloroplast Preparation.-Homogenisation of leaves and isolation of chloro plasts was carried out at O°C as described by James and Das (t957). About 30 g of precooled leaf material was ground in a chilled waring blender using 150mlof 0.3 M sucrose phosphate buffer pH 7.3. The buffer contained 0.3 M sucrose 0.067 m phospbate to give pH 7.3, 1.8x10.3 MgS04, 2xl0-4M versene. In some experiments where the chlo­

roplasts were used for estimation of nitrogen phosphorus, manganese magnes­ ium and iron the buffer was replaced by 0.35 M sodium chloride.

The leaf homogenate was spun at 600 X g for 2 minutes and the sediment which consisted of mostly wbole cells and cell debris was separated from the supernatant. The green supernatant was then centrifuged for 12 minutes at 1000 X g. The sediment contai­ ning chloroplasts was separated, washed and suspended in tbe sucrose phosphate buffer. This chloroplast suspension ~as used to study the metabolic activities.

Hill reaction activity of chloroplasts was measured by the method of Das and Reddy (t967). Chloroplasts were illuminated at 2000 ft. c. Rate of photophosphorylation of chloroplasts was determined following tbe method Asadaet al., (1965). Chloroplasts were iHuminated at 2000 ft. c. Radioactive phospbate with specific activity of 8 (LCi/O.1 ml was used per sample. Organic phosphorus was estimated according to Arney (1939). Chloroplasts ferredoxin was isolated from leaves by the procedure of Sanpietro and Lang (1958). Photoreductin of NADP by chloroplast ferredoxin was measured by tbe method out lined by Amon (I965).

Alcoholic extracts of dried chloroplast material was prepared following the method of Highkin and Frankel (1962). Reducing sugars and total soluble sugars were determined from the alcoholic extract by the method of Snell and Snell (1957) and Scott (1960). The non-reducing sugars were calculated according to the method of Loomis and Shull (1957). Starch was estimated from the alcohol insoluble residue by hydrolysis with 52 per cent per­ chloric acid. Glucose in the hydrolysate was estimated using the anthrone reagent as describ­ ed by McCreadyet al., (1950). Mineral constituents were estimated from dried (at 1000

C)

chloroplast meterial. Micro-Kjeldabl method of Markham (1942) was used to determine the contents of total nitrogen. Protein nitrogen was estimated according to the method of Thimann and Loos (1951). Soluble nitrogen was calculated by protein nitrogen from total nitrogen. Phosphorus, manganese, magnesium and iron contents of chloroplasts were deter­ mined from the ash solution prepared according to the 'procedure of Parks et al. (1943).

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SALT STRESS ON CHLOROPLASTMETABOLlSM 267 Phosphorus was determined by the method of Fiske and Subbarao and manganese was determined by theperiodate method of Peech as described by John and Ulrich (1959). Iron was estimated by 0- phenan throline method of Sandell (1950). Sodium and chloride were estimated by flame photometer. For the estimation of pH and electric conductivity, soil saturation extracts were prepared following the method of U. S. salinity laboratory staff (1954).

Statistical Analysis.-Least significant differences (LSD) at 5

%

probability were calculated for days after treatment (days), treatments and interaction (Days X treatments) by the method of analysis of variance.

RESULTS AND DISCUSSION

Hill reaction activity of chloroplasts was lowered by 29"10 and 40

%

with NaCl and NaaCOs treatments, respectively after 7 days of treatment. This was followed by a recovery

Table I. pH and conductivity of soil saturation extract

No. of Days after Conductivity

r Days after Sample

treat- first salt pH ECC 32°C

~,I sowing ments treatment mmflos/cm

0 Control 7.25 2.500

15 Control 7.20 1.!580

15 NaCI IT 7.00 9.520

15 NaoCO. IT 8.50 3.710

23 Control 7.11 1.380

23 NaCI IT 7 7.55 3.124

23 NaoCO. IT 7 8.52 2.830

30 Control 6.40 1.346

30 NaCI IT 15 7.20 2.708

30 Na.CO. IT 15 7.60 1.824

30 Control 6.80 1.320

30 NaCI liT 8.00 11.800

30 N8!CO. liT 9.10 5.200

37 Control 7.00 1.300

37 NaCI liT 23 7.90 4.759

37 Na.CO. lIT 23 8.90 2.399

45 Control 7.05 1.199

45 NaCI liT 30 7.60 3.305

45 NaoCO. liT 30 8.60 1.974

IT: First Salt Treatment liT: Second Salt Treatment

within about two weeks after treatment (Table 11). The activity was again decreased after second treatment by both the salts. The decrease was by about 32% and 41% with

~aCI and NaaCOs respectively. The activity was depressed more by Nll2COs than by treatment. The decreased Hill reaction activity was associated with the following impor­ I tant change viz., decrease in (a) manganese (b) magnesium and {cHron content of chloro­ I

plasts. The results are similar to those of Possingham and Spenser (1962) who found in

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M. SANJIVA REDDY AND V.S.R. DAS

268

spinach the dependance of Hill reaction activity on the level of manganese. Similar results were reported by Zallen (1969) with manganese deficient cells of chlamydamonas reinhardii, The soil salinity or alkalinity decreased the rates of photophsphorylation of chloroplasts after 30 days of treatment. Na2 COs depressed rates more than NaC). The decrease due to NaCI was 40% and 49% when PMS (Phenazinemethosulphate) and vitamin K were used as electron carriers respectively, with N~C03 the activity was decreased by 61% and

65% when PMS and vitamin K were used (Table III). The depres~ed rates of photophos­ phorylation of isolated chloroplasts may be due to the observed reduction of phos­ phorous content of chloroplasts (Table VIla) under salt treatments. .

Table lJ. Effect of NaCI and Na ..C03 on Hill reaction activity of chloroplasts

Optical density decrease/mg'

i

Chlorophyll

I

Days after treatment Treatment Treatment

7 ]5 23 30 ~eans

Control 7.59 8.43 12.61 11.45 ]0.02

NaCI 5.40 8.47 8.64 7.60 7.52

Na,COa 4.52 8.19 7.49 6.90 6.77

~ean for days 5'83 8.36 9.58 8.65

L.S.D. at 5% for days 0.486, Treatments 0.421 Interaction 0.847

Table III. Effect of NaCI and No2COs on photophosphorylation by choloroplasts

(tJ.moles of Pi esterified in light (2000 ft. c.) per mg chlorophyll/hour (average of duplicates)

After 30 days of Treatment

Treatments P.M.S. Electron Vitamin K

Carrier Electron Carrier

Control NaCI NazCO.

646.12 388.62 252.00

933.87 477.87 323.37

The reaction mixture contains tris-Hel buffer (pH 7-8), 124 !'-moles; MgCI., 5 tJ.moles; ADP, 3tJ.moles; Phellllfine methosulphate (P.~. S) O.ItJ.mole or Vitamin K3 (in 0.1 rol methanol) 0.3 !,-mole and deionised water to make the final volume 3.0 ml. Chloroplasts eqivalent to 0.1 rog chlorophyll and p q 8 tJ.Ci/O.l ml.

Salinity or alkalinily decreased the NADP reducing activity of chloroplast ferredoxin (TableIV).The activity was decreased by 34% and 711'~ with NaCI and Na2COa respectively after 30 days of treatment. The observed reduction in photochemical reactions would lead to a reduced supply of assimilatory power (ATP and NADPH2) which would have resulted

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-SALT STRESS ON CHLOROPLAST METABOLISM 269

Table IV. Effect of NaCI and Na2COa on photoreduction of NADP by chloroplast ferredoxin

After 30 days of treatment

Optical density decrease at 340 nm

Reaction mixture sUt width 0.4 rom

1. Chloroplast suspension + NAD P + ferredoxin

(400 !Lmoles) (Control sample) 0.116

2. Chloroplast suspension+NADP+ferredoxin

(440 !Lmoles) (Salt treated NaCI sample) 0.077

3. Chloroplast suspension+NADP+ferredoxin

(400 !Lmoles) (Salt treated Na.COa Sample) 0.034

Table V. Effect of NaCI and Na2C03 on carbohydrates of chloroplasts mg/g dry weight (mean of3 replications)

Treatments Days after salt treatment

---­

Treatments

7 15 23 30

(a) Starch

Control 33.51 29.69 31.50 39.76 33.61

NaCI 32.81 31.69 17.80 19.12 25.36

Na.COs 35.06 29.07 21.03 20.33 26.54

- - - ­

Means for days 34.04 30.15 23.44 26.40

L.S.D. at 5% for days 0.40, treatments 0.35, Interaction 0.70

(b) Reducing sugers

Control NaCI Na2CO.

3.11 2.22 2.32

5.55 9.34 5.97

5.53 2.21 2.10

6.57 4.05 3.12

5.19 4.45 3.37

Means for days 2.55 6.95 3.28 4.58

(c) Non-reducing sugars

Control 4.77 7.27 7.60 8.17 6.95

NaCl 3.70 12.66 15.63 11.98 10.97

Na2CO. 1.63 20.70 16.07 14.06 13.11

Means for days 3.36 13.54 13.14 11.37

L.S.D. at 5% for days, 1.38, treatments 1.19, Interaction 2.38.

Starch contents of chloroplasts were reduced from 22 to 30 days after salt treatment. The maximum reduction was 52% and 49% with NaZC03 respectively (Table Va). Reduc­

ing sugars were decreased initially due to salt treatments followed by a recovery within

two~weeks after treatment. The sugars were again decreased after second treatment. The decrease in reducing sugars was more in the samples taken after 22 days of treatment, i.e.

60% and 62% with NaCI and NazCOa respectively (Table Vb). Non-reducing sugars showed an initial decrease and an increase at the latter three samples. The increase was more with N~C03 treatment than with NaCI treatment (Table Vc), Total carbohydrates

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270 M. SANHVA RlIDDY AND V.S.R. DAS

(Starch+Total sugars) were decreased after 7,22 and 30 days of salt treatment. The decrease was more in the sample taken after 30 days of treatment. The decrease of reducing sugars with a concomitant increase of non-reducing sugars may be due to an increased synthesis of disaccharides under salt· stress. The.decruse of total carbohydrates (Starch + Total sugars) indicates a reduction in the amount of photosynthate by salinity or alkalinity. The results are similar to the observations of several other workers listed below who have worked with intact plants. Starch content was decreased in bean plants with higher moisture tension or osmotic pressure (Wadleigh and Ayers, 1945). Sodium and chloride salinity decreased monosaccharides but increased disaccharides of the leaves of tree Geobleia alopecuroides (Akopian, 1957). While studying the effect of salinity on gram seedlings Bharadwaj (1957) reported a reduction of reducing sugars.

Total nitrogen contents were increased in aU the samples due to salt treatments (Table VI a). The increase was more with NaCI than with NaaCOa treatment. Protein nitrogen of chloroplasts was decreased by the two salts. The decrease was more after 22 days of treatment, by 45% and 40% with NaCI and Na3COs respectively (Table VI b). The data also shows that salt increased soluble nitrogen of chloroplasts seveial fold over controls (Table VI c). The de<:rease in protein nitrogen with a concomitant increase in soluble nitrogen indi<:ate a poor capacity for protein synthesis under salt stress. When comparing the leaf expansion in dwarf red kindney beans with and without sodium chlo­ ride treatment, Nieman (t965) suggested that the reduction in the rate of RNA and protein synthesis per cell may be a primary effect of salt treatment. The increased levels of total nitrogen of chloroplasts are similar to the observations of Osawa (1957) with egg

Table Yf. .Effect ofNaCi and NaaCOa lT1'l total nitrogen, protein nitrogen and soluble nitrogen content of chloroplasts

mgig dry weight (mean of 3 replications)

Days after salt treatment

Treatments Treatment

J

7 15 23 30 means ;

_.-

1

(a) Total nitrogen

Control 4.85 11.30 10.40 9.11 8.92

NaCI 6.83 23.30 18.49 15.54 16.04

Na,co. 4.87 15.16 15.50 12.96 12.12

Means for days 5.51 16.58 14.81 12.53

b,SD•...f6r ~.32; «ea~O.28,IBteH.etion4.S6..

(b) Protein nitrogen

/

Control 4.25 9.93 9.81 8.54 8.13

NaCI 3.00 6.43 5.30 5.00 4.95

Na.CO. 3.34 7.06 5.93 5.53 5.46

Means for days 3.86 7.80 7.01 6.39

(c) Solllhie nitrogen

Control 0.60 1.37 0.63 0.57

NaCl 3.83 16.86 13.19 10.44­

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SALT STRBSS ON CHLOROPLAST METABOLISM . 271

plants. Bharadwaj (1957) with gram seedUngs,.nd Iwake et 01. (1958) with rice plants In

control plant chloroplasts there was a gradual increase in the contents of phosphorus and decrease in magnesium, manganese and iron. The contents of phosphorus, magnesium,

Table VIT. Effect of NaCI and Na2COa on phosphorus, magnesium, manganese, iron, sodium and chloride contents of chloroplasts,

mg/g dry weight (mean of 3 replications)

Days arter salt treatment

Treatments Treatment

7 15 23 30 Means

(0) Phosphoru,

Control 5.13 5.80 7.24 8.50 6.66

NaCi 5.54 5.31 6.50 4.46 5.45

NatCO, 5.27 5.10 5.25 4.30 4.98

Means for days 5.31 5.40 6.33 5.75

L.S.D at 5% for days N.S., Treatments 0.05, Interaction 0.10.

(b) Mag~Billm

Control 4.65 4.12 3.31 2.96 3.76

NaCl 2.87 2.59 1.S1 1.46 2.81

Na.cO, 2.39 2.66 ·1.10 1.08 2.41 .

Means for days 3.30 3.12 1.97 1.83

L.S.D. at 5% for days 0.67, Treatments 0.58, Interaction N.S.

(c) MangQlU!iltI I'/g. Dry Weight

Control 576.16 205.53 111.50 97.83 247.75

NaCI 219.33 171.53 76.13 57.83 131.20

NaaCO. 231.00 191.66 76.16 32.70 133.03

Means for days 342.16 189.57 88.13 62.78

(4) Iron p.g/g. Dry Weight

Control 95.54 83.70 66.53 58.20 75.54

NaCI 90.69 62.86 32.11 32.13 54.44

NaaC03 67.57 55.40 22.98 23.42 42.34

Means for days 84.60 67.32 40.20 37.91

L.S.D. at 5% for days 5.98, Treatments 5.18. Interaction 10.38.

(e) Sodium

Control 13.06 16.83 17.73 12.14 14.69

NaCI 17.53 18.22 31.70 18.99 21.61

Na.coa 19.86 19.22 35.16 20.00 23.56

Means for days 16.81 17.91 28.19 17.94

L.S.D. at 5% for days 1.31, Treatements 1.14, Interaction 2.28. if) CItIorititl

Control 6.23 6.26 7.80 8.10 7.09

NaC! 11.00 9.40 15.30 15.26 12.74

NaaCO. 5.20 5.83 6.13 6.46 5.90

Meansfo.. days 7.47 7.16 9.74 9.94

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272 M. SANJIVA REDDY AND V.S.R. DAS

manganese and iron in chloroplasts were .depressed by the two salts NaCI and NaaCOs (Table VII).

There was an increase in the contents of sodium and chloride of chloroplasts with NaCI treatment. Sodium carbonate treatment increased sodium in chloroplasts with a little decrease in chloride (Table VlIl). It appears that the adjustment of chloroplasts to these excess ions may be achieved by loss of other ions such as Mn++, Mg++ and Fe+++ etc. of chloroplasts which in turn results in derangement of chloroplast metabolism. Seve­ ral other works reported higher uptake of sodium and chloride by plants with higher salt concentration in the root medium (Oswa, 1957, Abdel Salam Elkadi, 1965, Green­ way, 1964).

pH and conductivity of soil saturation extracts (SSE) were estimated at all the four sampling dates viz., 7, 15, 22 and 30 days of salt treatment (Table 1). The derangement of chloroplast metabolism was more at the sampling dates where pH and conductivity of SSE were higher i.e. after 7,22 and 30 days of treatment. The effect was more with sodium carbonate particularly in photochemical reaction. Hence the specific ion effect of carbonate was as toxic to the plant at lower concentrations when compared to sodium chloride.

It is concluded that salinity or alkalinity depressed the rates of photochemical re­ actions viz., Hill reaction activity, rate of photophosphorylation and NADP reducing acti­ vity, of chloroplast ferredoxin. The salts also depressed the levels of reducing sugars starch \ and total carbohydrates of chloroplasts followed by an increase of non-reducing sugars. Protein nitrogen was reduced with a concomitant increase of soluble nitrogen by the two salts. Mineral constituents lik~ phosphorus, magnesium, manganese and iron of chloroplasts were also reduced under salts stress. Thus the chloroplast metabolism is depressed under salt stress which eventually limit the growth of plants.

ACKNOWLEDGEMENTS

This investigation was carried out under the PL-480 Project (FG-IN-140 and A7­ CR-42). The authors wish to express their thanks to Dr. I. M. Rao, for helpful sugges­ tions and to Dr. M. P. Sastri, for his able help in statistical analysis.

REFERENCES

Abdel Salam, M. A. and Elkadi, M. A. (1965). Plant growth and mineral content of barley as related to irrigation with bicarbonate waters. Plant and soil 23: 377-84.

Akopian. B.A. (1957). Change in the composition of monosaccharides and disaccharides in Geobelia alopecuroides when grown on saline soils. Akad. Nauk. Arm~koi SSR DOK2S: 121-24.

Arney, S.E. (1939). Phosphate fractions in barley seedlings. Biocbem. J. 33: 1078. Amon, D.!. (1965). Ferredoxin and photosynthesis. Science., 149: 1460-69.

Asada, K. Kitoh. S., Deura, R. and Zenzaburokasai (l965). Effect of hydroxy sui phonates on photochemi­ cal reactions of spinach chloroplasts and participation of &lyoxylate in photophosphorylation.

Plant and Cell Physiol .• 6: 615-27.

Bharadwaj S.N. (1957). Physiological studies on salt tolerance in wheat and gram. Thesis submitted for Ph. D. degree of Agra University, India.

Das, V.S;R. and Reddy. M.S. (1967). Hill reaction activity of pepper fruit chloroplasts. Curr. Sci., 36:

272-73.

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SALT STRESS ON CHLOROPLAST METABOLISM 273

Highkin, H.R. and Frankel (1962). Studies of growth and metabolism of barley mutant lacking chloro­ phyll. Plant Physiol., 37: 814-2Q.

Iwake. S., Kawai, M. and Ikemoto, S. (1958). Studies on the sillt injury in rice plants XV I Proc. Crop. Sci. Soc. Japan 27: 77-79.

James, W.Q. and Das, V.S.R. (1957). The organization of respiration in chlorophyllous cells. New Phytol.,

3l: 435.

John, C.M. and Ulrich, A. (1959). II Analytical methods for use.in plant analysis. California Agricultural Experimental Station Bul. 766.

Kling, E.G. (1954). Moskov. Glavnyibotan Sad Biul USSR.• )8: 59-73. As cited by Bernstein, L. and . Hayward H.E. (1958). Pypsiology of salt tolerance. Ann. Rev. Plant. Physiol., 9: 25-46.

Loomis, W.E. and, Shull, C.A. (1937). Methods in Plant Physiology. McGraw Hill Book Co., New York, p.276.

Markham, R. (1942). A steam distillation apparatus suitable for microkjeldahl analysis. Biochem. J., 36:

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McCready, R.M., Guggole, J. Silviera, V. and Owens,

as.

(1950). Determination of starch and amylase in vegetables. Application to Peas. Anal. Chem., 92: 1156-58.

Nieman, R.H. (1965). Expansion of bean leaves and its suppression by salinity. Plant Physiol., 40: 156-61.· Oswa, T. (1957). Effects of various concentration of sodium chloride on the growth, flowering, fruit bearing

and chemical compoSition of egg plants in sand culture. J. Hort. Assoc. Japan .• 26: 9-14. Parks, R.Q. Charles Hurwitz, S.L. and Ellis G.H. (1943). Quantitiative microdetermination of twelve ele­

ments in plant tissue Ind. Eng. Chern. Anal. Ed., 15: 527. . Possingeam, J. V. and Spencer (1962). Manganese as a function of chloroplasts. Austr. J. Bioi. Sci., 15:

58·68.

Ramamoorthy, B. (1968). The scope for living with saline and alkaline conditions in India. Seventh NESA Regional irrigation practices seminar, Lahore, Pakistan, held on 16-28 Sept. 1968.

Russell, E.J. (1950). Soil conditions and plant growth, Longmans green Co. London.

Sanpietro, A. and Lang, H.M. (1958). J. Bioi. Chem., 231: 211. As cited by linskens, B.G., Sanwel, B.D. and Tracey M.V. (1964). Modren methods ofplant analysis VII 594.

Sandell, E.B. (1950). Colorimetric determination of trace metals (2nd ed) luter science publishers Inc. New York. As cited by Johnson, C. M. and Ulrich A. (1959). 2. Analytical methods for use in plant analysis. California AgricultUIal Experimental Station. Bulletin: 766:

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Helianthus an1UlS. L. Plant physiol., 35: 653-61.

Shakhov, A.A. (1956). Salt tolerance of plants. Moskva Aka Nauk USSR 551.

Snell, F.D. and Snell, C. T. (1957). Colorimetrimethods 0/analysis III. D. Vannostrand. New York.

Thimann, K..V. and Loos, G.M. (1957). Protein synthesis during wilter uptake by tuber tissues. Plant Physiol.,3l: 274.

U.S. salinity laboratory Staff. (1954). Diagnosis and improvement of saline and alkali soils. U.S.D.A. hand book No. 60.

Wadleigh, C.H. and Ayers, A.D. (1954). Plant Physioi., 20: 106-32. As cited by Bernstein, L. and Hay­ . ward, H.E. (1958). Physiology of salt tolerance Ann. Rev. Plant Physiol., 9: 25-46.

Zalleo, D.T. (1969). The Effect of manganese on chloroplast structure and photosynthetic activity of

chlamydomonas reinhardii. Plant Physioi., 44: 701-10.

Figure

Table I. pH and conductivity of soil saturation extract
Table I pH and conductivity of soil saturation extract . View in document p.3
Table III. Effect of NaCI and No2COs on photophosphorylation by choloroplasts

Table III.

Effect of NaCI and No2COs on photophosphorylation by choloroplasts . View in document p.4
Table IV. Effect ofNaCI and Na2COa on photoreduction of NADP by chloroplast ferredoxin

Table IV.

Effect ofNaCI and Na2COa on photoreduction of NADP by chloroplast ferredoxin . View in document p.5
Table Yf. .Effect ofNaCi and NaaCOa lT1'l total nitrogen, protein nitrogen and soluble nitrogen content ofchloroplasts

Table Yf.

Effect ofNaCi and NaaCOa lT1 l total nitrogen protein nitrogen and soluble nitrogen content ofchloroplasts . View in document p.6
Table VIT. Effect ofNaCI and Na2COa on phosphorus, magnesium, manganese, iron, sodium and chloride contents of chloroplasts,

Table VIT.

Effect ofNaCI and Na2COa on phosphorus magnesium manganese iron sodium and chloride contents of chloroplasts . View in document p.7

References

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