STUDIES ON PROTEIN SYNTHESIS IN TOMATO COTYLEDONS AND LEAVES. I. PROTEIN SYNTHESIS AND TURNOVER IN INTACT COTYLEDONS AND LEAVES

1. Details of aseptic culture of virus-free tomato seedlings usedin comparative in vivo and in vitro studies on protein synthesisare described.
2. Developmental changes in the levels of DNA,RNA, protein andchlorophyll content of seedling cotyledonsand leaves were recorded,and are related to protein synthesis.
3. Incorporation of isotopically labeled carbon into proteinwasfollowed both by photosynthetic uptake of ¹⁴CO₂ and by theuptakeof ¹⁴C-amino acids through the roots.
4. A marked stimulationby light of ¹⁴C uptake was observed, andthe higher rate of¹⁴C incorporation from ¹⁴CO₂ than from ¹⁴C-aminoacids intothe protein fraction is discussed in relation tothe pathwaysof protein synthesis in tomato leaves, and alsowith regardto protein turnover.

¹Present address: Dept. of Horticultural Science, Universityof Wisconsin, U.S.A.     

AUXIN-INDUCED GROWTH OP TUBER TISSUE OP JERUSALEM ARTICHOKE: III. EFFECT OF ACTINOMYCIN D ON AUXIN-INDUCED EXPANSION GROWTH AND RNA SYNTHESIS

1. The following results were obtained using tissue slices excisedfrom cold-stored Jerusalem artichoke tubers.
2. Actinomycin Dat the concentration of 20 µg/ml given duringthe agingperiod did not affect the subsequent expansion growthcausedby auxin or auxin plus kinetin.
3. Actinomycin D given in thegrowth period, on the other hand,strongly inhibited the expansiongrowth of tissue slices agedin the absence of the antibiotic.
4. In the growth period, auxin or auxin plus kinetin promotedtheincorporation of uracil-2-¹⁴C into RNA fraction.
5. ActinomycinD inhibited the incorporation of ³²P orthophosphateinto ribosomalRNA during the aging period.
6. 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.

¹A part of this paper was presented at the Conference on PlantGrowth Regulators held by the New York Academy of Sciences onMay 16, 1966.     

ORGANIC ACID SYNTHESIS IN RESPONSE TO EXCESS CATION ABSORPTION IN VACUOLATE AND NON-VACUOLATE SECTIONS OF CORN AND BARLEY ROOTS

1. ¹⁴CO₂ fixation into organic acids in tips and proximal sectionsof both corn and barley roots was studied as a function of thenature and concentration of the salt in the external solution.
2. In comparison with the level of ¹⁴CO₂ fixation by vacuolateproximal sections in KCI, incorporation was markedly enhancedin K₂SO₄ and diminished in CaCk. By contrast, non-vacuolateroot tips were indifferent to the type of external salt withrespect to UCO₂ incorporation into organic acids.
3. The effectof salt type on organic acid formation from ¹⁴CO₂was most pronouncedat relatively high concentrations.
4. The conclusion was reachedthat organic acid synthesis in responsetoexcess cation uptakeis the result of cation movement into thevacuole, and thattransport into the vacuole is mediated bythe low-affinity componentof the dual mechanisms involved inion absorption.

¹Present address: Government Forst Experiment Station, Meguro,Tokyo.     

PROTEIN SYNTHESIS IN PANCREAS OF FASTED PIGEONS

The regulation of protein synthesis in the pigeon has been studied by comparing the capability of cell-free amino acid incorporating systems of membrane-bound and membrane-free polysomes prepared from fasted and fed birds. New methods were developed for isolating polysomes since techniques used for other tissues did not provide quantitative recovery of polysomal RNA. The sucrose gradient profile of polysomes from pigeon pancreas showed a predominance of trisome species. Although initiation factors are present on polysomes, it was found that polysomes in cell-free systems would not initiate protein synthesis without exogenous initiation factors. This suggested the presence of an inhibitor or regulator of protein synthesis. These studies show that fasting resulted in: (a) decreased amounts of polysomes; (b) disaggregation of polysomes to monosomes; (c) decreased capability of polysomes to synthesize nascent peptides and to initiate additional synthesis, apparently not related to concentration of initiation factors.     

PROTEIN SYNTHESIS IN VITRO IN RAT BRAIN AFTER SHORT-TERM PROTEIN STARVATION AND REFEEDING

Rats were fed a protein-free diet for 4 or 6 days. They were compared with rats kept on the same diet for 3 or 5 days and on adequate protein for one additional day. The incorporation of ¹⁴C-labelled amino acid into protein was studied in systems containing ATP, GTP, phosphoenolpyruvate, pyruvate kinase and if required, a mixture of unlabelled amino acids and either the 6000 g supernatant fraction of a brain homogenate or microsomes and soluble enzymes. The 6000 g supernatant fraction showed variation in amino acid incorporating activity as well as in RNase activity as measured by breakdown of labelled polyuridylic acid. There was no difference in RNase activity in isolated microsomes, but the amino acid incorporating activity was significantly higher in preparations obtained from rats fed one meal of protein after 5 days of protein-starvation.     

Studies on the destruction of indole-3-acetic acid by a species of Arthrobacter I. On the induction of the enzyme responsible for the destruction

1. The induction of an IAA-destroying enzyme in Arthrobacter sp.that can utilize IAA as its sole source of carbon and nitrogenwas investigated.
2. 1. The enzyme was most effectively inducedby 10–³ to2x10–³ M IAA, at pH 6.5.
3. 2. All testedIAA analogs were unable to induce the enzyme.Analogs otherthan indole-3-lactic acid were rather inhibitoryon the inductionwith IAA.
4. 3. The induction period was shortened with the ageof culturein both polypeptone and acetate media.
5. 4. Pretreatmentof the bacterium with IAA caused a shorteningof the inductionperiod.
6. 5. The induction was inhibited by various antibiotics,aminoacid analogs and nucleobase analogs.
7. 6. The inductionwas less remarkable in actively proliferatingcells than itwas in slowly proliferating ones.

(Received July 1, 1967; )     

PHYSIOLOGICAL AND BIOCHEMICAL CHANGES OF CARROT ROOT CALLUS DURING SUCCESSIVE CULTURES

1. The longer the period of stock culture, the more remarkableis the growth inhibition by 8-azaguanine in callus.
2. Chloramphenicol,5-methyltryptophane and mitomycin C exert greaterinhibitionon growth in CCL than in CCS.
3. Bud formation is inhibited bysome concentrations of chloramphenicolwithout accompanyinginhibition of the growth.
4. 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.
5. 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.

1. The rate of RNA breakdown in CCL wasnot so great as the rateof synthesis.
2. 8-azaguanine (10^–3and 10^–4M) 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.

1. In CCL 510^–5M 8.azaguaninedoes not affect total radioactivityincorporated into bulk RNA,but inhibits incorporation intoRNA of "mitochondrial fraction".

(Received December 23, 1964; )     

DISTRIBUTION AND TURNOVER OF PHOSPHATE COMPOUNDS IN GROWING CHLORELLA CELLS

1. Using the Chlorella cells which had been uniformly labeled with³²P, the distribution of phosphorus in various fractions ofcell material was investigated. Uniformly ³²P-labeled Chlorellawas further grown in a P-free medium or in a standard "cold"medium, and the change of distribution of ³²P (as well as theuptake of exogenous P) in various cell fractions was followed.
2. Analysis of the ³²P-labeled algal cells showed that the highestin P-content was the fraction of RNA followed by those of polyphosphates,lipid, nucleotidic labile phosphate compounds, DNA and protein(in decreasing order). ATP and ADP were found to be only minorfractions of the total labile phosphates.
3. On incubating the³P-labeled alga in a P-free medium, the P.contentsin the fractionsof DNA, protein, lipid and ATP increased, thosein polyphosphatesand ADP decreased, and that in RNA remainedalmost unchanged.When the ³²P-labeled alga was further grownin the normal "cold"medium, DNA and protein increased withthe expenditure of endogenous³²P, but with practically no incorporationof external P. Inthe meantime the P in polyphosphates decreasedconsiderably,and the RNA fraction incorporated a large amountof externalP but only a little of endogenous³²P.
4. It was inferred that,under the experimental conditions of thepresent study, thephosphorus used in the syntheses of DNA andprotein was primarilytaken from polyphosphates, while thatused in the synthesesof RNA, phospholipid and polyphosphateswas, for the most part,taken from the extracellular P-source.

¹A part of this paper was read at the Vth International Congressof Biochemistry, Moscow, August 10–16, 1961. (Received June 4, 1961; )     

STUDIES ON THE METABOLISM OF A SULFUR-OXIDIZING BACTERIUM II. THE SYSTEM OF CO2-FIXATION IN THIOBAC1LLUS THIOOXIDANS

1. In the early stage of CO₂-fixation by Thiobacillus thiooxidans,which was incubated aerobically in the presence of sulfur, mostpart of the fixed carbon was found in the phosphate ester fraction.
2. The fixation was inhibited by NaF, picolinic acid, PCMB, azide,dipyridyl, o-phenanthroline, monoiodoacetic acid, and arsenite,each in the concentration range where the sulfur oxidation wasnot affected strongly.
3. The crude extract of this organismcould fix CO₂ in the presenceof ATP, R-5-P and Mg⁺⁺. Most partof the fixed carbon was foundin PGA.
4. The crude extract showedthe CO₂-fixation coupled with the H₂S-oxidationin the presenceof ADP.
5. An appreciable reduction of PGA could not be detectedin thepresence of reducing systems, involving TPNH and DPNH.

(Received March 6, 1962; )     

Purification and properties of the photoactive particle corresponding to photosystem II

1. 1) Purification of the photoactive particle corresponding tophotosystem II (particle II) was achieved using a combinationof procedures including digitonin- and Triton X-100-treatments,sonication, and differential- and density-gradient centrifugations.
2. 2) The "purified" particle II preparation showed only oxygenevolution activity and showed no NADP⁺ photoreduction activityeven when an electron donor couple was added.
3. 3) The chemicalcompositions of this particle and of the particlecorrespondingto photosystem I (particle I) were compared withrespect tothe composition and contents of their chlorophylls,carotenoids,cytochromes, plastoquinones, protein and lipid.Marked differenceswere found.
4. 4) Using the two photoactive particles I and IIlacking therespective counterpart activity, a partial successwas attainedin reconstituting a system, in which photoinducedelectron flowfrom water to NADP⁺ was observed, provided thatsuitable intermediateelectron carriers, e. g. plastoquinoneand plastocyanin, wereadded.
5. 5) The nature of the two photoactiveparticles obtained andtheir relationship to particles so farreported are discussed.

¹This study was aided by grants from the Ministry of Education(407160-1965, 91402-1966, 1967). Financial support from SanyoBroadcasting Scientific Foundation is also acknowledged withcordial thanks. (Received October 23, 1968; )     

Biological activity of phyllosinol, a phytotoxic compound isolated from a culture filtrate of Phyllosticta sp.

1. 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.
2. Phyllosinol reduced root growth in rice seedlings by 60% at10^–4 M, whereas stimulation of root elongation occurredat a concentration range from 10^–9 to 10^–5 M.
3. Phyllosinolat 2.5x10^–4M promoted adventitious root formationin epicotylsof Azukia cuttings by about 100%. Promotion waspartly reducedby simultaneous application of cysteine.
4. IAA-induced elongationof isolated Avena coleoptile sectionswas inhibited by phyllosinolat a concentration range from 10^–5to 10^–3M.
5. Sulfhydrylcompounds, i.e. cysteine and glutathione relievedinhibitioncaused by phyllosinol in IAA-induced elongation ofAvena coleoptilesections.
6. GA₃-induced elongation of wheat leaf sections wasslightly inhibitedby phyllosinol at 10^–4M.
7. Phyllosinolalso has antibiotic activity. Among the organismstested, Phycomycetesand Gram-negative bacteria appeared mostsusceptible to phyllosinol.

(Received April 21, 1970; )     

Studies on the destruction of indole-3-acetic acid by a species of Arthrobacter II. Properties of the oxidation system

1. Some properties of the IAA-oxidizing activity of lyophilizedcells of Artkrobacter sp. were examined.
2. 1. IAA oxidationseems not to be catalysed by peroxidase, polyphenoloxidase,laccase or dehydrogenase, but by an oxidase systemdifferentfrom the one reported earlier.
3. 2. The optimal pH for the oxidizingsystem is ca. 6.0, and thesystem is comparatively stable atpH 5 to 10.
4. 3. The optimal substrate (IAA) level is 10^–3M.
5. 4. Activity is inhibited by metal-chelating reagents, suchassodium azide, potassium cyanide, sodium diethyldithiocarbamate,potassium xanthogenate and 8-hydroxyquinoline, and sulfhydrylreagents, such as iodoacetamide, monofluoroacetic acid, p-chloromercuribenzoate,isatin, ß-naphthoquinone and ß-naphthoquinone-4-sulfonate.Hydroxybenzoic acid, sulfosalicylic acid and 2,4-dichlorophenolare also inhibitory.
6. 5. None of the IAA analogs tested (indole,skatole, 2,3-dihydroxyindole,indole-3-aldehyde, -3-carboxylicacid, -3-propionic acid, -3-lacticacid, -3-butyric acid, 5-hydroxyindole-3-aceticacid and D,L-tryptophan) are oxidized by the cells, and someanalogs (indole-3-carboxylicacid, -3-propionic acid, -3-butyricacid, 5-hydroxyindole-3-aceticacid, naphthalene-acetic acidand 2,4-D) are inhibitory at comparativelyhigh concentrations.
7. 6. The oxidizing activity is not stimulated by Mn⁺⁺ and isinhibitedby Co⁺⁺, Cu⁺⁺ and Hg⁺⁺.
8. 7. The oxidizing activitydisappears completely within 6 hrat 30, but is kept unchangedat least for two weeks at –20.

(Received August 7, 1967; )     

Studies in the Nitrogen Metabolism of Apple Fruits: THE CLIMACTERIC RISE IN RESPIRATION IN RELATION TO CHANGES IN THE EQUILIBRIUM BETWEEN PROTEIN SYNTHESIS AND BREAKDOWN

1. A close parallelism in the drift of the rate of respirationand the protein-N/ non-protein-N ratio is shown to occur bothin apple fruits attached to the tree and when detached fromthe tree at various stages of development and stored for severalmonths at 12 C.
2. In detached fruits the fall in respirationwhich occurs immediately(during the first 48 hours) after pickingis only accompaniedby a concomitant fall in net protein invery young fruits inwhich active cell division is taking place.Subsequently, infruit of all ages when a climacteric rise inrespiration occursit is accompanied by a net increase in protein.
3. It is argued that the climacteric rise in respiration is aresultof increase in the level of protein which will be expectedtoreduce the ATP/ADP ratio.
4. Over the climacteric period,although rate of respiration andnet protein content both rise,R rises more rapidly than proteinand, subsequently, falls ata faster rate than P. It is suggestedthat this may be due tothe ‘new’ protein containinga higher proportionof enzyme(s) directly involved in respirationand leading, forexample, to a reduction in the ATP/ADP ratio.

     

Auxin-induced extension of the isolated epidermis of light-grown pea epicotyls

1. The effect of IAA and FC on the extension of isolated epidermisof light-grown Alaska pea epicotyls was studied under differentconditions with an extension apparatus. The following resultswere obtained.
2. The epidermis extended in response to low pHbuffer solutionof 1–10 mM, maximum extension being achievedat pH below5.5.
3. IAA, 5 mg/liter, caused, although not consistently,an extensionof epidermal strips in 1 mM buffer, but not at10 mM.
4. Consistent extension of the isolated epidermis dueto IAA wasobtained by addition of GTP, ATP, ITP or UTP (sodiumsalts),but not nucleosides, nitrogen bases or sugars.
5. A fungaltoxin, FC, at 10^–5 M induced extension of theepidermiswithout addition of the nucleoside triphosphates.
6. IAA andFC caused H⁺ extrusion in peeled epicotyl segments bothin thepresence and absence of GTP. IAA caused appreciable H⁺extrusionin the isolated epidermis only in the presence ofGTP, whereasH⁺ extrusion by the epidermis was induced by FCeven in theabsence of GTP.

From these results, we concluded that IAA induces extensionof the isolated epidermis under the above conditions throughthe mediation of H⁺ ions. (Received July 12, 1976; )     

Microbiological Synthesis of Fat: THE EFFECTS OF NITROGEN LEVEL ON THE METABOLISM OF PENICILLIUM LILACINUM THOM IN A SUCROSE MEDIUM

1. 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.
2. Under the defined experimental conditionsincreases in the concentrationof NO^–₂ 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.
3. Mediaof lower NO^–₃ concentration (for example, 0·32or 0·64 per cent. (w/v) NaNO^–₂;) yielded feltsricher in carbohydrate than were those grown in media of higherNO^–₂; 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.
4. Media of lower NO^–₃; concentration weremore conduciveto fat synthesis than those of higher NO^–₃;content.

     

COMPONENTS OF THE ELECTRON-TRANSFERRING SYSTEM IN ACETOBACTER SUBOXYDANS AND RECONSTRUCTION OF THE LACTATE OXIDATION SYSTEM

1. Cytochromes a₁⁵⁹⁰, b⁵⁶⁰, c₁⁵⁵⁴ and c₁⁵⁵² were isolated andpurifiedfrom a strain of Acetobacter suboxydans. The proceduresusedwere described in detail.
2. The main cytochrome band at550-560 mµ in intact cellssplitted at liquid air temperatureinto two bands, 551 mµ(strong) and 559 mµ (weak).
3. 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.
4. By some combinationsof isolated components reconstruction ofthe oxygen uptake systemcould be realized.
5. The oxygen-consuming activity of purifiedoxidase preparationswas accelerated by a-tocopherol but notby Emasoll 4130 andTween 80.
6. 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.
7. A possible scheme of the electron-transferringsystem of Acetobactersuboxydans was presented.

(Received May 16, 1960; )     

ENZYMIC FORMATION OF GLUTAMINE IN RICE-PLANT SEEDLINGS

1. Purified preparation from rice-plant seedling catalyses a stoichiometricreaction between ATP, glutamate, and NH₂OH in the presence ofMg⁺⁺ to form glutamyl hydroxamate, ADP and inorganic phosphate.
2. The method of purification and some of the properties of theenzyme are described. Co⁺⁺ can be substituted for Mg⁺⁺. Mn⁺⁺,NaF, and PCMB inhibit the enzyme strongly.
3. Inorganic orthophosphateis liberated from ATP by the additionof or cysteine in the presence of glutamate, Mg⁺⁺ andthis preparation. Glutamine was detectedin the reaction productsby paperchromatography.
4. The same preparation catalyses a reactionbetween gluta mineand NH₂OH in the presence of Mg⁺⁺ or Mn⁺⁺,ADP and inorganicphosphate, to form glutamyl hydroxamate.

¹ Present address: The Department of Chemistry, Faculty of Science,Kanazawa University, Kanazawa. (Received October 31, 1960; )     

COMPARATIVE STUDIES ON GROWTH, RESPIRATION, PHOTOSYNTHESIS AND PIGMENT CONTENT IN RHODOPSEUDOMONAS PALUSTRIS

1. Comparative studies were performed on growth, photosyntheticand respiratory activities, and pigment content in Rhodopseudomonaspalustris.
2. The growth of the organism, as influenced by variousculturalconditions such as light, aerobiosis, anaerobiosisand nutritionalfactors was investigated.
3. The respiratoryactivity of the bacterium was found to be higherin dark-growncells than in cells grown in the light. The photosyntheticactivitydid not significantly depend on the growth conditionsof theculture. Cells of younger cultures were found to be moreactivethan those of older cultures, with respect both to respirationand photosynthesis.
4. The pigment content was found to be higherin the light-growncells than in the dark-grown ones. The ratiophotosyntheticactivity/bacteriochlorophyll was significantlyhigher in thelatter than in the former.
5. Light, as well asvarious nutritional factors, was found toexert a marked accelerationon pigment formation, although ithas not yet been possibleto culture cells completely lackingin photosynthetic pigmentsand accordingly in photosyntheticactivity.

¹ Present address: Division of Dermatology and Urology, TokyoMetropolitan Hiroo Hospital, Tokyo. ² Present address: Department of Biology, Saitama University,Urawa. ³ Present address: Department of Biochemistry, School of Medicine,Yokohama University, Yokohama. ⁴ Present address: Department of Biophysics and Biochemistry,Faculty of Science, University of Tokyo, Tokyo. (Received July 23, 1961; )     

ROLE OF SULFUR IN THE CELL DIVISION OF CHLORELLA, WITH SPECIAL REFERENCE TO THE SULFUR COMPOUNDS APPEARING DURING THE PROCESS OF CELL DIVISION. I.

1. The role of sulfur in the cell division of Chlorella was studiedby following the fate of the sulfur supplied to the sulfur-deficientcells using ³⁵S as a tracer.
2. The sulfur-deficient cells whichwere unable to perform celldivision were made capable of divisionby the provision of ³⁶S-labeledsulfate under non-photosynthesizingconditions. Soon after theprovision of sulfate the labeledsulfur went rapidly into thecold perchloric acid (PCA)-solublefraction of algal cells,almost entirely in the form of sulfateand/or some other inorganicsulfur substance (s). With the lapseof time, more or less remarkablechanges occurred in the patternof ³⁵S-distribution in differentfractions of cell material.It was noticed that, at the onsetof cell division, a sulfur-containingpeptide-nucleotide compound(s)(SPN), which has been reportedearlier, appeared in a largequantity in the cold PCA-solublefraction, and that its quantitydecreased gradually during thesubsequent process of cell division,suggesting that the compoundwas transformed into some othersubstance (s), presumably withits nucleotide moiety going intonucleic acids and the peptidemoiety going into some essentialproteins.
3. Another noteworthyphenomenon observed during the process ofcell division wasthe incorporation of ³⁶S in a group of hotPCA-soluble substances.These sulfur substances were revealedto be sulfur-containingnucleotidic compounds, which might possiblybe some essentialcomponents of, or substances in close relationto, deoxypentosenucleic acid (DNA).

(Received March 1, 1960; )     

STUDIES ON PROTEIN METABOLISM IN HIGHER PLANTS. III. CHANGES IN THE SOLUBLE PROTEIN COMPONENTS WITH LEAF GROWTH

Water soluble protein was extracted from tobacco leaves (BrightYellow) and fractionated through chromatographic and immunochemicalprocedures. Six different UV-absorbing components, 7 antigeniccomponents, and 4 enzyme activities (phosphatase, protease,peroxidase and RNase) were detected on the Sephadex chromatogramsof leaf extracts. An UV-absorbing fraction, Fr. I-2, (immunochemicallydesignated as Pr. Imm-I) corresponded to the known "FractionI " of S. G. WILDMAN. The contents of the three antigenic components,Imm-a, Imm-b and Imm-c, having estimated molecular weights of1 to 2 10⁵, showed significant fluctuations during growthof the leaves. Peroxidase and another antigenic component (Imm-f)of smaller molecular weight showed increase with age of theleaves. Properties of the protein components thus detected wereinvestigated. (Received May 11, 1967; )