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1.
KAMIYA NOBURO; TAZAWA MASASHI; TAZAWA MASASHI; TAKATA TAKAKO 《Plant & cell physiology》1962,3(3):285-292
- A method has been developed to measure the hydraulic conductivityof the wall of the internodal cell of Nitella flexilis.
- Therate of water penetration through the cell wall varies linearlywith the hydrostatic pressure difference between the two sidesof the wall, showing that water permeability of the cell wallremains independent of the pressure difference applied.
- Waterpermeability of the cell wall is inversely proportionalto itsthickness It is 30µµmin3{dot}atm3when the thickness of the wall is 10 µ.
- Water permeabilityof the cell wall is the same for inward andoutward water flow.The polar water permeability of the entiremembrane system (walland protoplasmic part) of the living celldemonstrated by KAMIYAand TAZAWA (1) is, therefore, due tothe living protoplasmicpart.
- The ratio of the inward to outward permeability constantsofthe protoplasmic layer alone is higher than that of the entiremembrane system composed of protoplasmic layer and cell wall.
2.
- The inhibition by IAA (3-indolylacetic acid) and by IAN (3-indolylacetonitrile)of the growth of excised tomato roots cultured for 7 days at27 C. in a modified White's medium is described. 5109g./ml, IAA or 5106 g./ml, IAN cause approx, 50 per cent,inhibition of the linear growth of the main axis. With IAA decreasein number of laterals closely parallels the decrease in lineargrowth of the main axis; with IAN reduction in linear growthof the main axis occurs at concentrations above 108 whereasnumber of laterals does not decrease until the concentrationexceeds 106.
- Study of the course of cell elongationin the exodermal cellsshowed that in the standard medium andin media containing 5109IAA or 5106 IAN theprocess takes about 7 hours; thefinal cell lengths in IAA andIAN media are lower than in standardmedium owing to a slowerrate of elongation. The decrease inlinear growth of the mainaxis in presence of IAA could be accountedfor by the decreasein cell length; this was not the case withIAN. The implicationsof this are considered.
- Determinations of the distance (mm.)between, and of the numberof exodermal cells separating, theadjacent laterals in oneorthostichy showed that IAN enhancesthe frequency of lateralswhereas this is either unaffectedor decreased by IAA. The enhancementof lateral frequency inIAN arises from shortening of the cellsof the main axis anddecrease in the number of cells separatingadjacent laterals.
- The results are considered to support the view that IAN haseffects on root growth different from those of IAA. Study ofthe degree of inhibition of main axis growth and of alterationsin lateral frequency resulting from treatment with mixturesof IAA and IAN provided data which could also be most easilyexplained on this hypothesis.
3.
- The growth rate of cultured free-cells and their contents ofchlorophyll, Mg, K and N reached peaks on media containing Mn+= 60 and 80 meq per liter, or in which salts=2.7 and 3.6 atm.These concentration levels in the media were considerably higherthan those (Salts=1.52.0 atm) which produced good growthof intact plants. This discrepancy in media concentrations maybe due to differences in the culture conditions and in the morphologyof the materials.
- Very low Ca2+/(Mn+Ca2+) equivalentratios of 0.1 to 0.01in a medium were sufficient for good growthof free cells, whilegenerally about unity of the ratio is requiredin a medium forgood growth of intact plants. The differencein the medium compositionmay also be due to morphological differencesin the materials.
- Addition of Cl to the medium furtherpromoted the growthrate and friability of cell clumps.
- Alow concentration of 0.01 mM BO33 in the medium alsopromoted the friability of cell clumps.
4.
- The longer the period of stock culture, the more remarkableis the growth inhibition by 8-azaguanine in callus.
- Chloramphenicol,5-methyltryptophane and mitomycin C exert greaterinhibitionon growth in CCL than in CCS.
- Bud formation is inhibited bysome concentrations of chloramphenicolwithout accompanyinginhibition of the growth.
- Cell size and the contents of RNA,DNA, protein and lipid percell of CCL are greater than thoseof CCS, respectively. Thecontents per cell of RNA and lipidin "mitochondrial fraction"are higher in CCL than in CCS.
- Incorporationof guanine-8-14C into RNA of CCS occurs rapidlyin the first12 hr and slows down thereafter, but that in CCL-RNAincreasessteadily for 16 hr. This difference in rate of theincorporationafter 12 hr between CCS and CCL is principallydue to the differencein rate of the incorporation into RNAof nuclear, mitochondrialand soluble fractions.
- The rate of RNA breakdown in CCL wasnot so great as the rateof synthesis.
- 8-azaguanine (103and 104M) inhibits incorporationof guanine-8.14C intoRNA of both CCS and CCL during 14 hr,but thereafter (up to25 hr) it inhibits the incorporation intoCCL-RNA alone leavingthat into CCS-RNA unaffected.
- In CCL 5105M 8.azaguaninedoes not affect total radioactivityincorporated into bulk RNA,but inhibits incorporation intoRNA of "mitochondrial fraction".
5.
- Phyllosinol is a phytotoxic metabolite of Phyllosticta sp. Thissubstance at 100 µg/ml produced dark grey necrotic lesionson the leaf of red clover. Sensitivities of various plant speciesto phyllosinol differed both quantitatively and qualitatively.
- Phyllosinol reduced root growth in rice seedlings by 60% at104 M, whereas stimulation of root elongation occurredat a concentration range from 109 to 105 M.
- Phyllosinolat 2.5x104M promoted adventitious root formationin epicotylsof Azukia cuttings by about 100%. Promotion waspartly reducedby simultaneous application of cysteine.
- IAA-induced elongationof isolated Avena coleoptile sectionswas inhibited by phyllosinolat a concentration range from 105to 103M.
- Sulfhydrylcompounds, i.e. cysteine and glutathione relievedinhibitioncaused by phyllosinol in IAA-induced elongation ofAvena coleoptilesections.
- GA3-induced elongation of wheat leaf sections wasslightly inhibitedby phyllosinol at 104M.
- Phyllosinolalso has antibiotic activity. Among the organismstested, Phycomycetesand Gram-negative bacteria appeared mostsusceptible to phyllosinol.
6.
SHIBAOKA HIROH; ANZAI TADASHI; MITSUHASHI MIEKO; SHIMOKORIYAMA MASAMI 《Plant & cell physiology》1967,8(4):647-656
- Heliangine at 1104 M promoted the adventitious rootformation in hypocotyls of cuttings taken from light-grown (1,900lux) Phaseolus mungo seedlings. The promotion was almost completelyreversed by 3104 M uracil, uridine, cytidine, oroticacid or 6104 M carbamoyl DL-aspartic acid, and partlyby 3104 M thymine or thymidine. Neither 3104M cytosine, adenine, adenosine, guanine, guanosine nor a combinationof 3104 M carbamoyl phosphate and 3104 M L-asparticacid reduced the promotion by heliangine.
- Uracil did not reducethe inhibiting effect of heliangine onthe indoleacetic acidinduced elongation of etiolated Avenacoleoptile sections.
- Helianginein an aqueous uracil solution was recovered unchangedafter24-hr incubation at room temperature.
- The root formation ofPhaseolus cuttings was promoted also by2-thiouracil and 5-fluorouracil.The effect was reversed byorotic acid or carbamoyl asparticacid, but not by carbamoylphosphate plus aspartic acid.
- Ribonucleaseat 100 µg/ml increased the number of rootsprotruded fromhypocotyls of cuttings by about 260%.
- A possible interpretationfor the promotion of root formationby heliangine is offered.
7.
De Santis Aurelio; Borraccino Giuseppe; Arrigoni Oreste; Palmieri Ferdinando 《Plant & cell physiology》1975,16(5):911-923
The permeability properties and mechanism of Pi transport wereinvestigated in purified bean mitochondria.
- Purified bean mitochondria are impermeable to small moleculesand ions. However, Pi, arsenate, acetate and formate can enterthe osmotically active space of bean mitochondria.
- Nigericinor the association of valinomycin and FCCP cause mitochondrialswelling in isoosmotic potassium phosphate.
- The SH-blockingreagents mersalyl, pHMB and NEM inhibit variousmitochondrialfunctions dependent on the translocation of Piand arsenateacross the membrane. These include the respirationstimulatedby ADP, Ca2++Pi, and K++valinomycin +Pi; the swellingin ammoniumphosphate medium and, in the presence of nigericin,in potassiumphosphate medium; the energy-linked yalinomycin-inducedswellingand the subsequent CICCP-induced shrinking. The uncoupler-stimulatedrespiration, as well as the other processes when acetate issubstituted for Pi, are not influenced by SH reagents.
- Mersalyland pHMB cause complete inhibition at about 20 nmoles/mgprotein,whereas, NEM is effective at about 1 µmole/mgprotein.The inhibition by mersalyl and pHMB, but not that byNEM, issigmoidal and reversed by 2-mercaptoethanol. Non-inhibitoryamounts of mersalyl protect the Pi transport from irreversibleinhibition by NEM.
- We concluded that a carrier-mediated transportsystem for Piis present in bean mitochondria, and that someof its propertiesare similar to the Pi carrier of animal mitochondria.
8.
- Heliangine at 104M promoted the adventitious root formationin hypocotyls of cuttings taken from light-grown (1,900 lux)seedlings of Phaseolus mungo. The promotion was almost completelyreduced by simultaneously supplied 3104M cysteine or1.5104M cystine, but not suppressed by 3104Mof reduced glutathione, alanine or serine.
- A 4 hr pretreatmentwith 3104M cysteine made Phaseoluscuttings less sensitiveto heliangine, but cysteine suppliedafter the treatment withheliangine brought about no effecton the action of heliangine.
- Cysteine also removed the inhibiting effect of heliangineonthe indoleacetic acid-induced elongation of etiolated Avenacoleoptile sections.
- In an aqueous solution heliangine formedan addition productwith cysteine, indicating that cysteinecan inactivate helianginewithout any biological processes.
- On Phaseolus adventitious rooting, no effect was observedofp-chloromercuribenzoic acid, N-ethylmaleimide, 1,4-naphthoquinone,coumarin or penicillin. Reactivity toward sulfhydryl groupsalone does not qualify a substance to be a promotor of rootformation.
- Maleic hydrazide at 104M promoted root formation,butits effect was not removed by cysteine.
9.
- Apprehension over the adequncy of current techniques stimulateda detailed study of the time factor in the arsenate inhibitionof growth and respiration in excised stem and root sectionsof Pisum sativum.
- Growth inhibition by arsenate sets in veryslowly, its rateof onset being related to the molar concentration(C) of arsenateate by the relation where T50 is the time taken in hours to reduce the growthrateto 50 per cent of the control and K is a constant. An explanationof the physiological basis of this relationship is attempted.
- Estimates were made of the final steady growth rate (relativeto control) in various arsenate concentrations. The inhibitionscalculated from this rate are held to approximate to the truearsenate effect and are shown to be very different from thosecalculated from total growth measures.
- Respirationof growing stem sections is not inhibited by thelow arsenateconcentrations that inhibit growth. Some inhibitionis indicatedat high concentrations (3 ? 104M. and over)but onlyafter 15-20 hours of exposure.
- Two per cent sucrose has noeffect on the arsenate inhibiitionof stem growth. Sucrose,however, markedly stimulates respirationin stem sections, butthis stimulation is prevented by arsenate.
- The misinterpretationswhich may arise as a result of ignoringthe time factor in inhibitionstudies in excised organ sectionsare discussed and the desirabilityof constructing completegrowth curves in all such studies isstressed.
10.
The influence of salinity in the growing media on ribulose-1,5-bisphosphate (RuBP) carboxylase and on CO2 fixation by intactsugar beet (Beta vulgaris) leaves was investigated. RuBP carboxylase activity was mostly stimulated in young leavesafter exposure of plants for 1 week to 180 mM NaCl in the nutrientsolution. This stimulation was more effective at the higherNaHCO2 concentrations in the reaction medium. Salinity also enhanced CO2 fixation in intact leaves mostlyat rate-limiting light intensities. A 60 per cent stimulationin CO2 fixation rate was obtained by salinity under 450 µEm2 s1. At quantum flux densities of 150 µEm2 s1 (400700 nm) this stimulation was280 per cent. Under high light intensities no stimulation bysalinity was found. In contrast, water stress achieved by directleaf desiccation or by polyethylene glycol inhibited enzymeactivity up to fourfold at 1.2 MPa. Beta vulgaris, sugar beet, ribulose-1, 5-bisphosphate carboxylase, salt stress, water stress, carbon dixoide fixation, salinity 相似文献
11.
- Cytochromes a1590, b560, c1554 and c1552 were isolated andpurifiedfrom a strain of Acetobacter suboxydans. The proceduresusedwere described in detail.
- The main cytochrome band at550-560 mµ in intact cellssplitted at liquid air temperatureinto two bands, 551 mµ(strong) and 559 mµ (weak).
- Optical and physiological properties of the four cytochromeswere investigated. Lactic dehydrogenase activity was found tobe associated with cytochrome c1554. The two c1-type cytochromes,especially cytochrome c1554, persisted in their reduced formafter the purification through many steps.
- By some combinationsof isolated components reconstruction ofthe oxygen uptake systemcould be realized.
- The oxygen-consuming activity of purifiedoxidase preparationswas accelerated by a-tocopherol but notby Emasoll 4130 andTween 80.
- Some discussions were made onthe nature of terminal oxidase,the role of cytochrome c1552in the electron-transport system,and persistence of reducedstate of c1-type cytochromes.
- A possible scheme of the electron-transferringsystem of Acetobactersuboxydans was presented.
12.
The Permeability of Ammonia, Methylamine and Ethylamine in the Charophyte Chara corallina (C. australis) 总被引:1,自引:0,他引:1
Ritchie, R. J. 1987. The permeability of ammonia, methylamineand ethylamine in the charophyte Chara corallina (C. australis).J.exp. Bot. 38: 6776 The permeabilities of the amines, ammonia (NH3), methylamine(CH3NH2) and ethylamine (CH3CH2NH2) in the giant-celled charophyteChara corallina (C. australis) R.Br. have been measured andcompared. The permeabilities were corrected for uptake fluxesof the amine cations. Based on net uptake rates, the permeabilityof ammonia was 6?4?0?93 µm s1 (n = 38). The permeabilitiesof methylamine and ethylamine were measured in net and exchangeflux experiments. The permeabilities of methylamine were notsignificantly different in net and exchange experiments, norto that of ammonia (Pmethylamine = 6?0?0?49 µm s1(n = 44)). In net flux experiments the apparent permeabilityof ethylamine was slightly greater than that of ammonia andmethylamine (Pethylamine, net = 8?4?1?2 µm s1 (n= 40)) but the permeability of ethylamine based on exchangeflux data was significantly higher (Pethylamine, exchange =14?1?2 µm s1 (n = 20)). Methylamine can be validlyused as an ammonium analogue in permeability studies in Chara. The plasmalemma of Chara has acid and alkaline bands; littlediffusion of uncharged amines would occur across the acid bands.The actual permeability of amines across the alkaline bandsis probably about twice the values quoted above on a whole cellbasis i.e. the permeability of ammonia across the permeablepart of the plasmalemma is probably about 12 µm s1. Key words: Chara, permeability, ammonia, methylamine 相似文献
13.
- Two neutral plant hormones, one isolated recently from plants(3-indolylacetonitrile) and the other (3-indolylacetaldehyde)reported to be present in plants, are avaible as pure syntheticcompounds for investigation of their biological activities.This paper is mainly concerned with their effects on cellelongationin the Avena coleoptile
- 3-Indolylacetaldehyde is considerablyless active than 3-indolylaceticacid in the Avena straight-growthtest; for example, a 1.0 mg./l.solution of the aldehyde showsan activity equivalent to thatof a 0.1 mg./l. solution of theacid
- An acidic substance is produced in solutions of the aldehydeduring the period of assay. In some experiments it accountsfor all of the activity shown by the aldehyde solutions, onthe assumption that it is 3-indoylacetic acid, and in otherexperiments it shows a greater activity than that of the aldehydesolutions from which it was obtained. Therefore, it is concludedthat 3-indolylacetaldehyde, itself is either inactive or inhibitory.Acid production in aldehyde solutions in vitro is much lower,a fact which suggests that there is enzymatic oxidation of aldehydeto acid in the presence of coleoptiles.
- The activities of3-indolylacetaldehyde in the pea test andin root-inhibitionand of 3-indolylacetone in the straight-growthtest are brieflyreported.
- 3-Indolylacetonitrile is considerably more activethan 3-indolylaceaticacid in the Avena straight-growth test;for erample, a 0.1 mg./l.solution of the nitrile shows an activityequivalent to a 1.0mg./l. solution of the acid. The inhibitoryeffect at concentrationsabove 1.010.0 mg./l. is lesswith the nitrile than withthe acid.
- There is negligible productionof acid in solutions of the nitrileboth in vitro and in thepresence of Avena coleoptiles at temperaturesranging from 18?to 25? C. for varying lengths of time.The possibility of enzymaticconvesion of nitrile to acid insidethe cells of the coleoptileis discussed
- The activities of 3-indolylacetamide and of 2:4-dichlorophenoxyaceticacid and the corresponding nitrile are considered in this connexion
- The nitrile is destroyed by treatment with alkali but notbyacid. In the light of these results, it is desirable to re-examineprevious work on identification of auxins in plants by theiracid and alkali sensitivity. Evidence for the existence of thenitrile in a number of other plants is presented.
14.
- A study has been made of the relationships between the synthesesof carbohydrate, protein, and fat by Penicillium lilacinum Thomin presence of different amounts of sodium nitrate us a definedsucrose salts medium.
- Under the defined experimental conditionsincreases in the concentrationof NO2 in the medium werefollowed by increases in therates at which nitrogen and sugarwere taken up by the fungus,in the quantities assimilated,and in total and protein nitrogenin the felt. These conditionsprevailed so long as unassimilatedsugar was available.
- Mediaof lower NO3 concentration (for example, 0·32or 0·64 per cent. (w/v) NaNO2;) yielded feltsricher in carbohydrate than were those grown in media of higherNO2; content (0·96 or 1·28 per cent. (w/v)NaNO3 The carbohydrate content of the felts increased graduallyuntil the sugar in the medium was exhausted; carbohydrate contentthen decreased.
- Media of lower NO3; concentration weremore conduciveto fat synthesis than those of higher NO3;content.
15.
Une tude des cellules d'Euglnes et de leurs extraits prparsavec les ultra-sons, chauffs ou non chauffs (quelques heures 35), montre que:
- le chauffage ne dtruit pas la chlorophylle de faon notable;
- en prsence d'alcool, un agrgat de chlorophylle ayant unebanded'absorption 740750 mµ apparait dans lesextraitsd'Euglnes ges de plus de 11 jours;
- les jeunesEuglnes et les Euglnes ges et chauffes ne peuventformerl'agrgat absorbant aux grandes longueurs d'ondes;
- deux outrois complexes chlorophylliens diffrents sont impliqusdansla formation des agrgats qui absorbent 740 mµ.
16.
Three kinds of discs were taken from tobacco leaves whose lowerepidermis had been peeled off, half-peeled or unpeeled. Therole of the epidermis and its relation to the kinetin effecton chlorophyll degradation during senescence were studied. Ourresults follow.
- Chlorophyll degradation due to kinetin was retarded only whenthe lower epidermis was present.
- The decrease in chlorophyllcontent in leaf discs on water duringsenescence was nearlyproportional to the size of the lowerepidermis attached tothe discs; i.e., unpeeled discs>half-peeleddiscs>peeleddiscs.
- Cellular fractions possessing activity which induceschlorophylldegradation were extracted from the isolated lowerepidermis(i, ii) and its acetone powder (iii): (i) L-2 fraction(1.14d1.16)was separated by stepwise sucrose density-gradientcentrifugationfrom the 10,000?g pellet of the cell homogenate.(ii) The A-fraction(M.W.5,000) was precipitated with 080%saturation ofammonium sulfate from 105,000 ? g supernatantof cell homogenateand eluted in the void volume by SephadexG-25 column chromatography.(iii) The fraction precipitatedwith 030% saturationof ammonium sulfate from the 105,000?gsupernatant, containeda large amount of DNA and its activityremained even if DNAwas removed.
- Activity was not retainedwhen the fractions were obtained fromisolated lower epidermispretreated with 2?105 M kinetinfor 2 hr in darknessat 25?C.
17.
- Using Chlorella ellipsoidea as material, investigations weremade of the effects of ultraviolet irradiation upon variousactivities of cells at different developmental stages in theirlife cycle. Cell activities investigated were photosynthesis,respira tion, over-all growth, modes of synchronous growth andcell division as well as the formation of nucleic acids. Theu. v.- light applied was 30 µµW/cm2in intensityand 2537 Å in wavelength.
- The most u. v.-sensitive wasthe over-all growth activity, andin this respect the irradiationapplied at the L2-stage wasmore inhibitive than that givenat the D-stage. The next mostvulnerable was the photosyntheticactivity, the sensitivitybeing the same in the D- and L-cells.The most resistant towardu.v. was the endogenous respirationof D-cells followed by theirrespiration using exogenous glucoseas substrate. The L2-cellsappeared to be unable to use exogenousglucose as substrateof respiration, but their endogenous respirationwas considerablystronger than that of D-cells, and its u. v.-sensitivitywasthe same as that of glucose respiration of D-cells.
- WhenD-cells were u. v. irradiated immediately before the startofsynchronous culture, growth and cell division as well astheformation of DNA and RNA were retarded in proportion totheu. v.-dose applied. The division number (n) was normal (around4) at lower u.v.-doses (1-2 minute irradiation), but was reducedto a half (about 2) at a higher dose.
- When, during the synchronousculture, 1-minute u.v.- irradiationwas applied at various stagesof the ripening phase, the divisionwas retarded, but the cells,after attaining an abnormally largesize, divided into about8. If the irradiation was given atthe L4-stage, the divisionnumber was practically unmodified(n=4.5), although the divisionwas somewhat retarded comparedwith that of the control culture.When a 1-minute irradiationwas given at the L2-stage, thereoccurred an apparent stimulationof DNA- and RNA-formation,a phenomenon which corresponds tothe production of a largernumber of daughter cells than itwas the case in control cultures.
- Thus the cells which were moderately u.v.-irradiated at differentstages of synchronous culture were able to complete their lifecycle, but later a certain portion of irradiated cells becameunable to grow normally.
18.
- The woody shoots of young saplings of Fraxinus.excelsior andAcer Pseudo-platanus in pots were subjected to continuous coolingto about 2° C. during the growth season, with the resultthat radial growth was almost completely inhibited throughoutthe woody stem.
- The chilling did not adversely affect extensiongrowth exceptthat it was later in commencement and proceededmore slowly.
- If the temperature around the stem is loweredfrom 2° C.to 0° C., water conduction is cut down tosuch an extentas to cause wilting of the leafy shoots; turgidityis recoveredwhen the temperature is again raised to 2°C.
- This wilting effect is discussed particularly in relationtothe part played by living cells in the upward movement ofwaterin the wood.
19.
- The following results were obtained using tissue slices excisedfrom cold-stored Jerusalem artichoke tubers.
- Actinomycin Dat the concentration of 20 µg/ml given duringthe agingperiod did not affect the subsequent expansion growthcausedby auxin or auxin plus kinetin.
- Actinomycin D given in thegrowth period, on the other hand,strongly inhibited the expansiongrowth of tissue slices agedin the absence of the antibiotic.
- In the growth period, auxin or auxin plus kinetin promotedtheincorporation of uracil-2-14C into RNA fraction.
- ActinomycinD inhibited the incorporation of 32P orthophosphateinto ribosomalRNA during the aging period.
- In the growth period, the incorporationof 32P into RNA wasenhanced by auxin and was inhibited by actinomycinD, more remarkablyin ribosomal RNA than in lighter RNA.
20.
- In the presence of NADP+ and Mg++, the bundle sheath strandsisolated from corn (Zea mays) leaves by cellulase treatmentsdecarboxylated malate in the light at an initial rate (200 µmoles/mgchl.hr), which was sufficient to account for photosyntheticCO2 fixation in intact leaves. This rate gradually slowed downand then stopped. The final level of the malate decarboxylatedwas approximately equal to the amount of NADP+ added.
- Rapidand continued decarboxylation of malate was observed whenNADP+,3-phosphoglyceric acid and ATP (and Mg++) were addedtogether.The addition of ADP instead of ATP showed a similareffect.Light did not show any effect on the malate decarboxylationin the presence of ATP or ADP.
- When malate was added to thebundle sheath strands in the presenceof exogenous NADP+ NADP+was rapidly reduced. The reductionstopped after 2 min when,73% of the added NADP+ was reduced.The further addition of3-phosphoglyceric acid and ATP broughtabout a decrease in theNADPH-level, which rose again to attaina new steady level.
- The transfer of radioactivity from (1-14C-3-phosphoglycericacid to dihydroxyacetone phosphate in the bundle sheath strandsin the presence of ATP and NADP+ was greatly enhanced by theaddition of malate.
- In the presence of ribose 5-phosphateand ATP, the rate of 14C-transferfrom (4-14C)-malate to theintermediates of the reductive pentosephosphate cycle was equalto that of 14CO2 fixation in the light.