According to our model of pregenetic molecular coding, nucleobase doublets anticodons were, by stereochemical affinities, the primary codons for amino acid letters of the primitive peptide sequences. Such doublets, anticipating the base sequences of the «modern» triplet codons of the reading strand of DNA would have been initially stabilized along polyphosphate chains by phosphoamidic dehydrating condensation with tripolyphosphate into riboseless prenucleic acids.
{"title":"Polarity at onset of genetic coding. II, Primary recognition of amino acids by base doublets of prenucleic sugarless polymers secondarily taken over by ribonucleic acids","authors":"G. Turian","doi":"10.5169/SEALS-740272","DOIUrl":"https://doi.org/10.5169/SEALS-740272","url":null,"abstract":"According to our model of pregenetic molecular coding, nucleobase doublets anticodons were, by stereochemical affinities, the primary codons for amino acid letters of the primitive peptide sequences. Such doublets, anticipating the base sequences of the «modern» triplet codons of the reading strand of DNA would have been initially stabilized along polyphosphate chains by phosphoamidic dehydrating condensation with tripolyphosphate into riboseless prenucleic acids.","PeriodicalId":55478,"journal":{"name":"Archives Des Sciences","volume":"63 ","pages":"95-104"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72543135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Effect of the photoperiod on the plasma membrane ATP-dependent H+-pumping activity of spinach petioles. The plasma membrane from spinach (Spmac/a o/eracea, cv.Nobel) petioles was purified by phase partitioning and the use of enzyme markers showed that this fraction was highly enriched in plasma membrane vesicles. This fraction was almost devoid of phosphohydrolase activities originating from endomembranes (tonoplastes, mitochondria, non specific phosphatases and golgi apparatus). The ATP-dependent H+ pumping activity in this fraction was Mg^+ and K+ dependent and was not stimulated by valinomycin. It was unsensitive to nitrate (tonoplaste ATPase inhibitor) but sensitive to vanadate (plasma membrane ATPase inhibitor). This activity was specific for ATP and had a pH optimum around 6.5. The kinetic constants (Km.,pp and for ATP) of the H+ pumping activity of the purified plasma membrane were determined from plants grown in short days (vegetatives) and from similar plants induced by 24 h of continuous light. Whereas Km have not been changed after light induction, values of and the activity in the presence of 0.5 mB ATP have been increased suggesting a regulation of the enzyme after light induction. Key-words: H+-ATPase, Plasma membrane, Sp/rtac/a o/eracea. Abbreviations: ADP. Adenosine diphosphate; ATP, Adenosine triphosphate; BSA, bovine serum albumin; BTP, bis-tris-propane (1.3-bis (tris (hydroxymtehyl) methylamino) propane); DTT, dithiothreitol; GTP. Guanosine triphosphate; 1DP, inosine diphosphate; Mes. 4-morpholinoethane sulfonic acid; PNPP, p-nitrophenylphosphate; PMSF, phenylmethylsulfonylfluoride: PPj, Pyrophosphate; Tris, Tris (hydroxy methyll-aminomethane; UDPG, uridine diphosphoglucose.
{"title":"Effect of the photoperiod on the plasma membrane ATP-dependent H + -pumping activity of spinach petioles","authors":"J. Bellamine, H. Greppin","doi":"10.5169/SEALS-740264","DOIUrl":"https://doi.org/10.5169/SEALS-740264","url":null,"abstract":"Effect of the photoperiod on the plasma membrane ATP-dependent H+-pumping activity of spinach petioles. The plasma membrane from spinach (Spmac/a o/eracea, cv.Nobel) petioles was purified by phase partitioning and the use of enzyme markers showed that this fraction was highly enriched in plasma membrane vesicles. This fraction was almost devoid of phosphohydrolase activities originating from endomembranes (tonoplastes, mitochondria, non specific phosphatases and golgi apparatus). The ATP-dependent H+ pumping activity in this fraction was Mg^+ and K+ dependent and was not stimulated by valinomycin. It was unsensitive to nitrate (tonoplaste ATPase inhibitor) but sensitive to vanadate (plasma membrane ATPase inhibitor). This activity was specific for ATP and had a pH optimum around 6.5. The kinetic constants (Km.,pp and for ATP) of the H+ pumping activity of the purified plasma membrane were determined from plants grown in short days (vegetatives) and from similar plants induced by 24 h of continuous light. Whereas Km have not been changed after light induction, values of and the activity in the presence of 0.5 mB ATP have been increased suggesting a regulation of the enzyme after light induction. Key-words: H+-ATPase, Plasma membrane, Sp/rtac/a o/eracea. Abbreviations: ADP. Adenosine diphosphate; ATP, Adenosine triphosphate; BSA, bovine serum albumin; BTP, bis-tris-propane (1.3-bis (tris (hydroxymtehyl) methylamino) propane); DTT, dithiothreitol; GTP. Guanosine triphosphate; 1DP, inosine diphosphate; Mes. 4-morpholinoethane sulfonic acid; PNPP, p-nitrophenylphosphate; PMSF, phenylmethylsulfonylfluoride: PPj, Pyrophosphate; Tris, Tris (hydroxy methyll-aminomethane; UDPG, uridine diphosphoglucose.","PeriodicalId":55478,"journal":{"name":"Archives Des Sciences","volume":"130 1","pages":"27-34"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86365167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Opposite morphogenetic changes have been provoked by growing A. arbuscula in the presence of two antimicrotubular agents: taxol maintained vegetative hyphal elongation growth and thereby prevented their apical differentiation into couples of male-female gametangia; nocodazole prevented germ tube outgrowth, induced emergence of epihyphal rhizoids and led to altered positioning of intrahyphal nuclei. Primary hyphal growth in the presence of taxol prevented the nocodazole-induced morphogenetic disturbance.
{"title":"Morphogenetic changes provoked by two antimicrotubular drugs with opposite effects during the developmental cycle of Allomyces arbuscula","authors":"Isabelle Schoenenberger-Sola, G. Turian","doi":"10.5169/SEALS-740270","DOIUrl":"https://doi.org/10.5169/SEALS-740270","url":null,"abstract":"Opposite morphogenetic changes have been provoked by growing A. arbuscula in the presence of two antimicrotubular agents: taxol maintained vegetative hyphal elongation growth and thereby prevented their apical differentiation into couples of male-female gametangia; nocodazole prevented germ tube outgrowth, induced emergence of epihyphal rhizoids and led to altered positioning of intrahyphal nuclei. Primary hyphal growth in the presence of taxol prevented the nocodazole-induced morphogenetic disturbance.","PeriodicalId":55478,"journal":{"name":"Archives Des Sciences","volume":"25 1","pages":"69-76"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73749219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Un modele d'evolution prebiotique de molecules codantes reposant sur l'interaction de leurs liaisons faibles et fortes peut relier (1) le code originel a 1 lettre d'acides amines lies par covalence en (cyclo)peptides, par (2) sa releve par code prenucleique a doublets de 2 lettres de bases associees par liaisons polyphospho (P)-amidiques (N), au (3) code moderne a 3 lettres par triplets de nucleotides, singularise par l'insertion mediane du ribose (P-r-N) a la releve par l'ARN.
{"title":"Polarity at onset of genetic coding. I, Bipolar bondings in two-step takeover of peptide templates by prenucleic-ribonucleic acids","authors":"G. Turian","doi":"10.5169/SEALS-740424","DOIUrl":"https://doi.org/10.5169/SEALS-740424","url":null,"abstract":"Un modele d'evolution prebiotique de molecules codantes reposant sur l'interaction de leurs liaisons faibles et fortes peut relier (1) le code originel a 1 lettre d'acides amines lies par covalence en (cyclo)peptides, par (2) sa releve par code prenucleique a doublets de 2 lettres de bases associees par liaisons polyphospho (P)-amidiques (N), au (3) code moderne a 3 lettres par triplets de nucleotides, singularise par l'insertion mediane du ribose (P-r-N) a la releve par l'ARN.","PeriodicalId":55478,"journal":{"name":"Archives Des Sciences","volume":"253 1","pages":"213-227"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86711493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The plasma membrane from Arabidopsis thaliana leaves was purified by phase partitioning and the use of enzyme markers showed that this fraction was highly enriched in plasma membrane. This fraction was almost devoid of phosphohydrolase activities originating from endomembranes (tonoplastes, mitochondria, non specific phosphatases and golgi apparatus). The H⁺ATPase in this fraction was Mg²⁺ dependent and stimulated by K⁺ and valinomycin. It was almost unsensitive to nitrate (tonoplaste ATPase inhibitor) but sensitive to vanadate (plasma membrane ATPase inhibitor) and other known ATPase inhibitors, especially the omeprazol inhibited both ATPase activity and plant growth. This activity was specific for ATP with a Kmapp of 392 μM and had a pH optimum around 6.7. On the other hand, 1 μM of lysophosphatidylcholine stimulated the H⁺ transport activity into the purified plasma membrane vesicles. Higher concentration of this detergent (30 μM) was inhibitory.
{"title":"Proton transport ATP dependent driven by the plasma membrane ATPase from Arabidopsis thaliana leaves: biochemical characterization","authors":"J. Bellamine, H. Greppin","doi":"10.5169/SEALS-740421","DOIUrl":"https://doi.org/10.5169/SEALS-740421","url":null,"abstract":"The plasma membrane from Arabidopsis thaliana leaves was purified by phase partitioning and the use of enzyme markers showed that this fraction was highly enriched in plasma membrane. This fraction was almost devoid of phosphohydrolase activities originating from endomembranes (tonoplastes, mitochondria, non specific phosphatases and golgi apparatus). The H⁺ATPase in this fraction was Mg²⁺ dependent and stimulated by K⁺ and valinomycin. It was almost unsensitive to nitrate (tonoplaste ATPase inhibitor) but sensitive to vanadate (plasma membrane ATPase inhibitor) and other known ATPase inhibitors, especially the omeprazol inhibited both ATPase activity and plant growth. This activity was specific for ATP with a Kmapp of 392 μM and had a pH optimum around 6.7. On the other hand, 1 μM of lysophosphatidylcholine stimulated the H⁺ transport activity into the purified plasma membrane vesicles. Higher concentration of this detergent (30 μM) was inhibitory.","PeriodicalId":55478,"journal":{"name":"Archives Des Sciences","volume":"26 1","pages":"159-171"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83152947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
La cinetique de l'induction de fluorescence de la chlorophyll a (Chl a) depuis sa valeur minimale Fo jusqu'a sa valeur maximale Fm, est un indicateur de la reduction nette de la plastoquinone primaire (Qa⁻). Dans ce papier nous avons examine l'effet de la haute temperature (autour de 44°C) sur l'ascension de la cinetique de la fluorescence de Chl a des feuilles de pomme de terre et de petit pois, en utilisant un systeme sans obturateur qui nous permet de mesurer des signaux de fluorescence de 10 μs jusqu'a 120 s. Apres un traitement a la chaleur, la fluorescence variable de la Chl a a ete considerablement diminuee. Cependant, en augmentant la temperature ou la duree du traitement, la fluorescence caracteristique appelee la transition O-J-I-P est transformee en une fluorescence O-K-J-I-P avec une nouvelle etape rapide appelee "etape-K", detectee aux environs de 200 μs. Une grande depression apparait apres l'etape "K", suivie d'une augmentation de l'intensite de la fluorescence de la Chl a. Nous avons essaye de determiner l'origine et de faire une interpretation photochimique des changements observes en utilisant du NH₂OH connu comme donneur electron du PSII, et du DCMU qui est connu comme inhibiteur de la chaine de transport d'electrons entre Qa⁻ et Qb. Avec les differentes donnees obtenues, nous proposons que l'apparition de cette nouvelle "etape-K" est due a une inhibition du "water-splitting-system" et a une partielle inhibition de la chaine de transport d'electrons entre PPhe⁻QA et PPheQA⁻.
{"title":"The polyphasic rise of the chlorophyll A fluorescence (O-K-J-I-P) in heat-stressed leaves","authors":"Berouba Guisse, A. Srivastava, R. Strasser","doi":"10.5169/SEALS-740252","DOIUrl":"https://doi.org/10.5169/SEALS-740252","url":null,"abstract":"La cinetique de l'induction de fluorescence de la chlorophyll a (Chl a) depuis sa valeur minimale Fo jusqu'a sa valeur maximale Fm, est un indicateur de la reduction nette de la plastoquinone primaire (Qa⁻). Dans ce papier nous avons examine l'effet de la haute temperature (autour de 44°C) sur l'ascension de la cinetique de la fluorescence de Chl a des feuilles de pomme de terre et de petit pois, en utilisant un systeme sans obturateur qui nous permet de mesurer des signaux de fluorescence de 10 μs jusqu'a 120 s. Apres un traitement a la chaleur, la fluorescence variable de la Chl a a ete considerablement diminuee. Cependant, en augmentant la temperature ou la duree du traitement, la fluorescence caracteristique appelee la transition O-J-I-P est transformee en une fluorescence O-K-J-I-P avec une nouvelle etape rapide appelee \"etape-K\", detectee aux environs de 200 μs. Une grande depression apparait apres l'etape \"K\", suivie d'une augmentation de l'intensite de la fluorescence de la Chl a. Nous avons essaye de determiner l'origine et de faire une interpretation photochimique des changements observes en utilisant du NH₂OH connu comme donneur electron du PSII, et du DCMU qui est connu comme inhibiteur de la chaine de transport d'electrons entre Qa⁻ et Qb. Avec les differentes donnees obtenues, nous proposons que l'apparition de cette nouvelle \"etape-K\" est due a une inhibition du \"water-splitting-system\" et a une partielle inhibition de la chaine de transport d'electrons entre PPhe⁻QA et PPheQA⁻.","PeriodicalId":55478,"journal":{"name":"Archives Des Sciences","volume":"3 1","pages":"147-160"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89474133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Intermolecular H bonding is bioevolutionarily motive by (1) promoting prototypic self-assembly of H₂O molecules, and (2) providing template forces for stacking cyclic peptides into prevital proproteinaceous nanotubes possibly endowed with self-reproductive competence.
{"title":"New trends in polarity. III, Dipolar hydrogen bondings as homotemplate forces for pregenetical evolution","authors":"G. Turian","doi":"10.5169/SEALS-740254","DOIUrl":"https://doi.org/10.5169/SEALS-740254","url":null,"abstract":"Intermolecular H bonding is bioevolutionarily motive by (1) promoting prototypic self-assembly of H₂O molecules, and (2) providing template forces for stacking cyclic peptides into prevital proproteinaceous nanotubes possibly endowed with self-reproductive competence.","PeriodicalId":55478,"journal":{"name":"Archives Des Sciences","volume":"53 1","pages":"173-182"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72484931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Au cours de l'annee 1991, 119 echantillons d'eau furent recoltes en vue d'analyses diverses: recensement des organismes planctoniques preleves au filet et a la pompe; comptages des especes les plus abondantes; mesures du poids de matiere seche et du volume du macrozooplancton: calcul du biovolume de matiere fraiche du phytoplancton et de l'indice de diversite des especes. Lors de chaque prelevement, la transparence et la temperature de l'eau ont ete mesurees. Les divers parametres sont discutes et compares a ceux de l'annee precedente.
{"title":"Plancton du lac Léman (XVII): année 1991","authors":"J. Naef, Paul Martin","doi":"10.5169/SEALS-740444","DOIUrl":"https://doi.org/10.5169/SEALS-740444","url":null,"abstract":"Au cours de l'annee 1991, 119 echantillons d'eau furent recoltes en vue d'analyses diverses: recensement des organismes planctoniques preleves au filet et a la pompe; comptages des especes les plus abondantes; mesures du poids de matiere seche et du volume du macrozooplancton: calcul du biovolume de matiere fraiche du phytoplancton et de l'indice de diversite des especes. Lors de chaque prelevement, la transparence et la temperature de l'eau ont ete mesurees. Les divers parametres sont discutes et compares a ceux de l'annee precedente.","PeriodicalId":55478,"journal":{"name":"Archives Des Sciences","volume":"168 1","pages":"103-136"},"PeriodicalIF":0.0,"publicationDate":"1993-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86746190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nous avons teste la sensibilite du mouvement circadien foliaire a des interruptions par la lumiere ou l'obscurite, ou a des traitements chimiques: un point de singularite a ete observe ou le rythme circadien est bloque. A ce moment, on observe des mouvements foliaires ultradiens avec une reponse amplifiee par un traitement a l'EGTA. Nous proposons, comme hypothese, que le mouvement foliaire circadien resulte essentiellement du controle et de la coordination (proteine specifique) par les signaux du plasmalemme de rythmes ultradiens electrochimiques et fondamentaux dans les cellules foliaires.
{"title":"Point de singularité et propriétés rythmiques des feuilles de Phaseolus vulgaris L.","authors":"H. Greppin, Saad Kayali","doi":"10.5169/SEALS-740461","DOIUrl":"https://doi.org/10.5169/SEALS-740461","url":null,"abstract":"Nous avons teste la sensibilite du mouvement circadien foliaire a des interruptions par la lumiere ou l'obscurite, ou a des traitements chimiques: un point de singularite a ete observe ou le rythme circadien est bloque. A ce moment, on observe des mouvements foliaires ultradiens avec une reponse amplifiee par un traitement a l'EGTA. Nous proposons, comme hypothese, que le mouvement foliaire circadien resulte essentiellement du controle et de la coordination (proteine specifique) par les signaux du plasmalemme de rythmes ultradiens electrochimiques et fondamentaux dans les cellules foliaires.","PeriodicalId":55478,"journal":{"name":"Archives Des Sciences","volume":"16 1","pages":"347-360"},"PeriodicalIF":0.0,"publicationDate":"1993-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73467101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
La floraison a ete induite chez des plantes d'epinards (Spinacia oleracea L. cv. Nobel) par un traitement photoperiodique de 24 heures de lumiere continue, et correspondant a un depassement de 12 heures de la photoperiode critique de l'epinard. Des apex caulinaires, representant des echantillons de 30 mg en PF, ont ete preleves sur des plantes induites et non induites. Ces apex ont ete incubes dans une solution enzymatique contenant de la cellulase, de la driselase et du macerozyme. Une methode originale de traduction in vitro dans le lysat de protoplastes d'apex d'epinards induits et non induits a ete mise au point. Elle a permis de mettre en evidence, par marquage a la methionine S³⁵ les proteines neosynthetisees. Parallelement, des protoplastes intacts d'apex ont ete incubes en presence de methionine S³⁵. Les proteines neosynthetisees, dans le lysat de protoplastes ou dans les protoplastes intacts, ont ete analysees par electrophorese sur gel de Polyacrylamide en conditions denaturantes et revelees par fluorographie. Dans le lysat de protoplastes d'apex, trois proteines de masses molaires apparentes respectivement de 32, 36 et 38 kDa augmentaient en quantite dans les protoplastes d'apex induits. Une autre proteine de masse molaire apparente de 25 kDa diminuait quantitativement apres induction. Dans les protoplastes intacts, six proteines de masses molaires apparentes respectivement de 21, 23, 32, 36, 38 et 64 kDa augmentaient quantitativement alors que quatre autres proteines de 22, 26, 37 et 77 kDa diminuaient quantitativement. Quatre de ces dernieres modifications (25, 32, 36 et 38 kDa) etaient similaires a celles trouvees dans le lysat de protoplastes d'apex.
{"title":"Modifications du profil protéique dans les protoplastes d'apex d'épinards ( Spinacia oleracea L. cv. Nobel) lors de l'induction florale","authors":"F. Lefort, H. Greppin","doi":"10.5169/SEALS-740333","DOIUrl":"https://doi.org/10.5169/SEALS-740333","url":null,"abstract":"La floraison a ete induite chez des plantes d'epinards (Spinacia oleracea L. cv. Nobel) par un traitement photoperiodique de 24 heures de lumiere continue, et correspondant a un depassement de 12 heures de la photoperiode critique de l'epinard. Des apex caulinaires, representant des echantillons de 30 mg en PF, ont ete preleves sur des plantes induites et non induites. Ces apex ont ete incubes dans une solution enzymatique contenant de la cellulase, de la driselase et du macerozyme. Une methode originale de traduction in vitro dans le lysat de protoplastes d'apex d'epinards induits et non induits a ete mise au point. Elle a permis de mettre en evidence, par marquage a la methionine S³⁵ les proteines neosynthetisees. Parallelement, des protoplastes intacts d'apex ont ete incubes en presence de methionine S³⁵. Les proteines neosynthetisees, dans le lysat de protoplastes ou dans les protoplastes intacts, ont ete analysees par electrophorese sur gel de Polyacrylamide en conditions denaturantes et revelees par fluorographie. Dans le lysat de protoplastes d'apex, trois proteines de masses molaires apparentes respectivement de 32, 36 et 38 kDa augmentaient en quantite dans les protoplastes d'apex induits. Une autre proteine de masse molaire apparente de 25 kDa diminuait quantitativement apres induction. Dans les protoplastes intacts, six proteines de masses molaires apparentes respectivement de 21, 23, 32, 36, 38 et 64 kDa augmentaient quantitativement alors que quatre autres proteines de 22, 26, 37 et 77 kDa diminuaient quantitativement. Quatre de ces dernieres modifications (25, 32, 36 et 38 kDa) etaient similaires a celles trouvees dans le lysat de protoplastes d'apex.","PeriodicalId":55478,"journal":{"name":"Archives Des Sciences","volume":"64 1","pages":"69-84"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85776753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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