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Lucienne Desfontaines - One of the best experts on this subject based on the ideXlab platform.
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Changes in soluble carbohydrates and activities of sucrose-cleaving enzymes during tuberization of Pachyrhizus erosus (L.) Urban
1996Co-Authors: Lucienne Desfontaines, Victor Vaillant, Philippe ConstantAbstract:Developmental time course of soluble carbohydrates as well as sucrose metabolizing enzymes were determined in Yam bean (Pachyrhizus erosus) tap root under inductive environment. Until 5 weeks after sowing (WAS), tap root contained essentially sucrose (Suc). From 6 WAS (starting of tuber bulking), glucose (glc) and fructose (Fru) concentration increased greatly. The ratio of Fru to Glc was close to 1 during tuberization, indicating that Suc was very likely hydrolysed via invertase. Activities of sucrose synthase and neutral invertase were high whereas acid invertase activity was quite low. Neutral invertase activity increased by 3 between 5 and 7 WAS, but sucrose synthase and acid invertase activities remained unchanged. The levels of fru, glc and neutral invertase were positively correlated indicating its main role in the accumulation of reserve sugars in developing tuber.
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Assimilate partitioning in Pachyrhizus erosus tubers under short days
Physiologia Plantarum, 1995Co-Authors: Victor Vaillant, Lucienne DesfontainesAbstract:The distribution of 14 C products in yam bean (Pachyrhizus erosus) plants was measured as a function of time after a 14 CO 2 pulse-chase experiment under short-day conditions. The 14 C declined by more than 7O% in leaves during the first two hours, indicating that they actively exported carbon. Tubers were strong storage sinks for carbon and accumulated more than 8O% of the total incorporated 14 C after a 72-h chase. The data show that, although sucrose represented about 21% of the tuber non-structural carbohydrate, i.e. 15% of the tuber dry weight, 14 C did not accumulate in sucrose but in glucose, fructose and starch. The data indicate the existence of a separate sucrose pool which is affected only very slowly by recent assimilates. As a result, recent photosynthates, temporarily stored, may contribute to the reservoir of carbon available for nitrogen fixation. The data also suggest the existence of two distinct pools of amino acids in the tuber, one utilized mostly for protein synthesis and the other probably stored in the vacuole
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BIOLOGICAL NITROGEN FIXATION AFTER STEM CUTTING IN TUBEROUS Pachyrhizus erosus
1994Co-Authors: Victor Vaillant, Lucienne DesfontainesAbstract:Yam bean (Pachyrhizus erosus) a tuber-forming legume, is particularly suitable for evaluating the potential availability of the plant reserve carbohydrates for nitrogen fixation (Vaillant et al., 1990,1993). The tuber of this species contains soluble sugars and starch which account, respectively, for 32 and 15% of dry weight. Furthermore, tuberous and non-tuberous plants may be avai lable in inductive or noninductive environment (Robin et al., 1990; Sorcnsen et al., 1993). A stem cutting experiment was conducted with tuberous Pachyrhizus erosus in order to evaluate its potential for maintaining N fixation after aphotosynthate stress. This paper report the effects of such a treatment on the Acetylene Reduction Assay (ARA) of nodules and on the concentration of N fixation products in underground organs.
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Remobilization of Pachyrhizus erosus reserve carbohydrates in response to stem girdling
Plant Physiology and Biochemistry, 1993Co-Authors: Victor Vaillant, Lucienne DesfontainesAbstract:The role of tuber in controlling the supply of assimilates to nitrogen fixation activity was examined in nodulated yam bean (Pachyrhizus erosus) by means of girdling tuberous and non-tuberous plants. The acetylene reduction activity of nodules dropped to 80% of control values by 1 h after girdling. In tuberous plants it remained stable for another 4 h whereas it declined to 35% of the control in non-tuberous plants. The 14 C-assimilate which was not distributed to the underground portion of the girdled plants accumulated in the leaf as sucrose. Within 5 h after girdling, plants showed a decreased amount of 14 C-labelled sucrose in tuber relative to non girdled plants
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Etude comparée jours longs/jours courts de l'effet d'un traitement à la chaleur de la tige de Pachyrhizus erosus (L.)
1992Co-Authors: Victor Vaillant, Lucienne DesfontainesAbstract:Nous avons étudié l'influence de la destruction d'un anneau de phloéme par un traitement à la chaleur de la tige, sur la teneur en glucides et l'activité nitrogénase des nodosités de Pachyrhizus erosus. Le traitement a interrompu la translocation des assimilats de la partie aérienne de la plante vers le système racinaire, mais a peu d’effets sur la photosynthèse.En jours longs, l’activité de fixation des nodosités et leur teneur en saccharose sont réduites de 65% après 5h. En jours courts par contre, l’activité de fixation des nodosités n’est réduite que de 20% après 5h. Le saccharose décroît régulièrement dans les nodosités puis ré-augmente. Cette différence de réponse physiologique au stress est liée la présence en jours courts d’un tubercule qui joue un rôle tampon dans la fourniture de substrats énergétiques pour l’activité de fixation des nodosités.
Victor Vaillant - One of the best experts on this subject based on the ideXlab platform.
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Relationship between tuberization and the appearance of a neutral invertase activity in Pachyrhizus erosus L Urban 183
Tropical Agriculture, 1998Co-Authors: Victor Vaillant, Fabian PiletAbstract:Changes in soluble carbohydrates and PAGE pattern of tap root proteins were monitored in yam bean [Pachyrhizus erosus (L.) Urban] tap root under inductive (short days) and non-inductive (long days) environments. Up to five weeks after sowing (WAS), tap roots contained essentially sucrose. Under the short-day environment, a neutral invertase (NI) activity appeared from 6 WAS, concomitantly with glucose and fructose accumulation. Under the long-day environment, soluble carbohydrates as well as the pattern of proteins remained unchanged throughout root development. From these data it is concluded that NI controls the accumulation of hexoses in tap roots and is regulated by short days.
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Changes in soluble carbohydrates and activities of sucrose-cleaving enzymes during tuberization of Pachyrhizus erosus (L.) Urban
1996Co-Authors: Lucienne Desfontaines, Victor Vaillant, Philippe ConstantAbstract:Developmental time course of soluble carbohydrates as well as sucrose metabolizing enzymes were determined in Yam bean (Pachyrhizus erosus) tap root under inductive environment. Until 5 weeks after sowing (WAS), tap root contained essentially sucrose (Suc). From 6 WAS (starting of tuber bulking), glucose (glc) and fructose (Fru) concentration increased greatly. The ratio of Fru to Glc was close to 1 during tuberization, indicating that Suc was very likely hydrolysed via invertase. Activities of sucrose synthase and neutral invertase were high whereas acid invertase activity was quite low. Neutral invertase activity increased by 3 between 5 and 7 WAS, but sucrose synthase and acid invertase activities remained unchanged. The levels of fru, glc and neutral invertase were positively correlated indicating its main role in the accumulation of reserve sugars in developing tuber.
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Assimilate partitioning in Pachyrhizus erosus tubers under short days
Physiologia Plantarum, 1995Co-Authors: Victor Vaillant, Lucienne DesfontainesAbstract:The distribution of 14 C products in yam bean (Pachyrhizus erosus) plants was measured as a function of time after a 14 CO 2 pulse-chase experiment under short-day conditions. The 14 C declined by more than 7O% in leaves during the first two hours, indicating that they actively exported carbon. Tubers were strong storage sinks for carbon and accumulated more than 8O% of the total incorporated 14 C after a 72-h chase. The data show that, although sucrose represented about 21% of the tuber non-structural carbohydrate, i.e. 15% of the tuber dry weight, 14 C did not accumulate in sucrose but in glucose, fructose and starch. The data indicate the existence of a separate sucrose pool which is affected only very slowly by recent assimilates. As a result, recent photosynthates, temporarily stored, may contribute to the reservoir of carbon available for nitrogen fixation. The data also suggest the existence of two distinct pools of amino acids in the tuber, one utilized mostly for protein synthesis and the other probably stored in the vacuole
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BIOLOGICAL NITROGEN FIXATION AFTER STEM CUTTING IN TUBEROUS Pachyrhizus erosus
1994Co-Authors: Victor Vaillant, Lucienne DesfontainesAbstract:Yam bean (Pachyrhizus erosus) a tuber-forming legume, is particularly suitable for evaluating the potential availability of the plant reserve carbohydrates for nitrogen fixation (Vaillant et al., 1990,1993). The tuber of this species contains soluble sugars and starch which account, respectively, for 32 and 15% of dry weight. Furthermore, tuberous and non-tuberous plants may be avai lable in inductive or noninductive environment (Robin et al., 1990; Sorcnsen et al., 1993). A stem cutting experiment was conducted with tuberous Pachyrhizus erosus in order to evaluate its potential for maintaining N fixation after aphotosynthate stress. This paper report the effects of such a treatment on the Acetylene Reduction Assay (ARA) of nodules and on the concentration of N fixation products in underground organs.
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Remobilization of Pachyrhizus erosus reserve carbohydrates in response to stem girdling
Plant Physiology and Biochemistry, 1993Co-Authors: Victor Vaillant, Lucienne DesfontainesAbstract:The role of tuber in controlling the supply of assimilates to nitrogen fixation activity was examined in nodulated yam bean (Pachyrhizus erosus) by means of girdling tuberous and non-tuberous plants. The acetylene reduction activity of nodules dropped to 80% of control values by 1 h after girdling. In tuberous plants it remained stable for another 4 h whereas it declined to 35% of the control in non-tuberous plants. The 14 C-assimilate which was not distributed to the underground portion of the girdled plants accumulated in the leaf as sucrose. Within 5 h after girdling, plants showed a decreased amount of 14 C-labelled sucrose in tuber relative to non girdled plants
N.p Stamford - One of the best experts on this subject based on the ideXlab platform.
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Functional properties of yam bean (Pachyrhizus erosus) starch.
Bioresource technology, 2003Co-Authors: E.a. Mélo, Nadia Krieger, M. P. C. Silva, Tânia Lúcia Montenegro Stamford, N.p StamfordAbstract:Abstract The study was carried out in order to determine and establish the functional characters of starch extracted from yam bean (Pachyrhizus erosus (L) Urban) compared with cassava starch. Yam bean is a tropical tuber legume easily grown and holds a great potential as a new source of starch. Yam bean starch shows functional properties which are peculiar to those of most starch root crops. Gelatinization temperature (53–63 °C) and the pasting temperature (64.5 °C) are less than those of cereal starch, however, the swelling power is high (54.4 g gel/g dried starch). Yam bean starch paste presents a high viscosity profile, high retrogradation tendency and low stability on cooking. The functional properties of yam bean starch, similar to those of cassava starch, allows yam bean to be used as a potential new source of starch.
Nadia Krieger - One of the best experts on this subject based on the ideXlab platform.
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Functional properties of yam bean (Pachyrhizus erosus) starch.
Bioresource technology, 2003Co-Authors: E.a. Mélo, Nadia Krieger, M. P. C. Silva, Tânia Lúcia Montenegro Stamford, N.p StamfordAbstract:Abstract The study was carried out in order to determine and establish the functional characters of starch extracted from yam bean (Pachyrhizus erosus (L) Urban) compared with cassava starch. Yam bean is a tropical tuber legume easily grown and holds a great potential as a new source of starch. Yam bean starch shows functional properties which are peculiar to those of most starch root crops. Gelatinization temperature (53–63 °C) and the pasting temperature (64.5 °C) are less than those of cereal starch, however, the swelling power is high (54.4 g gel/g dried starch). Yam bean starch paste presents a high viscosity profile, high retrogradation tendency and low stability on cooking. The functional properties of yam bean starch, similar to those of cassava starch, allows yam bean to be used as a potential new source of starch.
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Enzymatic hydrolysis of starch from jacatupe (Pachyrhizus erosus L. Urban) by thermostable amylolytic enzymes
Starch - Starke, 1996Co-Authors: E. De A. Mélo, Nadia Krieger, R. Vieira, Nonete Barbosa Guerra, M. P. C. Silva, John F. KennedyAbstract:An alternative source of starch obtained from jacatupe (Pachyrhizus erosus L. Urban) a tropical tuber has been characterized enzymatically using amylolytic enzymes. The best hydrolysis conditions were obtained using α-amylase of 13.56U/ml at pH 7.0 and 80°C; amyloglucosidase of 177.5U/ml at a pH range from 3.5 to 4.0 and 70°C, respectively. Michaelis constants were determined in terms of substrate concentration; Km and Vmax for α-amylase and amyloglucosidase were found to be 16.8g/1, 1.49g/1, 11.2μmol/h and 3.10μmol/h, respectively. Scanning electron microscopy studies suggest that the enzymes tunnelled into the granular interior of the starch granules and then hydrolysed from within, along concentric holes - a well established phenomenon in the starch granules from classical crops. Enzymatische Hydrolyse der Starke von Jacatupe (Pachyrhizus erosus L. Urban) durch thermostabile amylolytische Enzyme. Eine alternative Quelle von Jacatupe (Pachyrhizus erosus L. Urban), einer tropischen Wurzel, wurde enzymatisch unter Anwendung von amylolytischen Enzymen charakterisiert. Die besten Amylolyse-Bedingungen wurden erhalten durch Verwendung von α-Amylase mit 13,56U/ml bei pH 7,0 und 80°C, bzw. 177,5U/ml Amyloglucosidase im pH-Bereich von 3,5 bis 4,0 und 70°C. Die Michaelis-Konstanten wurden in Abhangigkeit von der Substratkonzentration bestimmt. Km und Vmax fur α-Amylase und Amyloglucosidase betrugen 16,8g/1, 1,49g/1, 11,2μmol/h und 3,10μmol/h. Raster-Elektronenmikroskopie-Untersuchungen lassen vermuten, das die Enzyme durch Tunnelbildung in das Innere der Starkekorner gelangt sind und von innen her hydrolysiert haben in Richtung konzentrischer Locher, ein gut etabliertes Phanomen in den Starkekornern klassischer Starkelieferanten.
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Physicochemical properties of Jacatupé (Pachyrhizus erosus L. Urban) starch
Starch - Stärke, 1994Co-Authors: Enayde De Almeida Melo, Nadia Krieger, Tâania Lúcia Montenegro StamfordAbstract:The physicochemical properties of the starch extracted from Jacatupe (Pachyrhizus erosus L. Urban) were studied. The small-sized granules (approximately
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physicochemical properties of jacatupe Pachyrhizus erosus l urban starch
Starch-starke, 1994Co-Authors: Enayde De Almeida Melo, Nadia Krieger, Tâania Lúcia Montenegro StamfordAbstract:The physicochemical properties of the starch extracted from Jacatupe (Pachyrhizus erosus L. Urban) were studied. The small-sized granules (approximately <10μm long) present varying geometric forms: round, cupoliform and convex-biconcave shaped granules predominate. The amylose content is 23% and crystallinity pattern is type A. Values for intrinsic viscosity and absolute density are similar to those for cassava (Manihot utilissima) starch. Extraction and purification procedures are easy to perform. Root productivity is high (50t/hectare). According to these results, Jacatupe roots can be considered a new alternative source for starch production. Physikalisch-chemische Eigenschaften von Jacatupe (Pachyrhizus erosus L. Urban)-Starke. Die physikalisch-chemischen Eigenschaften von Jacatupe (Pachyrhizus erosus L. Urban)-Starke wurden untersucht. Die kleinen Korner (annahernd <10μm lang) stellen verschiedene geometrische Formen dar: runde, kuppelformige sowie convex-binconcav gestaltete Korner herrschen vor. Der Amylosegehalt betragt 23%, und das Kristallinitatsmuster ist vom Typ A. Die Werte der inneren Viskositat und der absoluten Dichte sind ahnlich denen der Starke aus Cassava (Manihot utilissima). Extraktion und Reinigung sind leicht durchzufuhren. Die Wurzelproduktivitat ist hoch (50t/Hektar). Entsprechend dieser Befunde konnen Jacatupe-Wurzeln als neue alternative Rohstoffquelle fur die Starkeproduktion angesehen werden.
Himmatul Fuad - One of the best experts on this subject based on the ideXlab platform.
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Pengaruh ekstrak bengkuang (Pachyrhizus erosus) terhadap kadar trigliserida darah tikus putih (rattus norvegicus) yang diberi diet tinggi lemak
2013Co-Authors: Himmatul FuadAbstract:Himmatul Fuad, G0010094, 2013. Pengaruh Ekstrak Bengkuang (Pachyrhizus erosus) terhadap Kadar Trigliserida Darah Tikus Putih (Rattus norvegicus) yang Diberi Diet Tinggi Lemak. Skripsi. Fakultas Kedokteran, Universitas Sebelas Maret, Surakarta. Latar Belakang : Bengkuang diketahui mengandung flavonoid, isoflavon, fenol, alkaloid, vitamin C dan saponin yang mempunyai efek antiherlipidemia. Penelitian ini bertujuan untuk mengetahui pengaruh ekstrak bengkuang (Pachyrhizus erosus) terhadap trigliserida darah tikus putih (Rattus norvegicus) yang diberi diet tinggi lemak. Metode Penelitian : Penelitian ini merupakan penelitian true eksperimental dengan the post test only with control group. Subjek dari penelitian ini adalah 30 ekor tikus putih jantan galur Sprague Dawley, usia sekitar 2 bulan, berat badan kurang lebih 137-238 gram. Subjek dibagi 6 kelompok perlakuan yang diambil secara random. Seluruh kelompok diadaptasikan selama 7 hari. Pada hari ke-8 seluruh kelompok kecuali kelompok kontrol normal, diberi diet tinggi lemak 2 ml/200 gram BB/hari selama 21 hari. Untuk kelompok kontrol positif diberi tambahan simvastatin dengan dosis 0,18 mg/200 gram BB/hari, kelompok kontrol negatif diberi aquadest 2 ml/200 gram BB/hari, kelompok perlakuan 1 diberi dosis ekstrak 70 mg/200 gram BB/hari, kelompok perlakuan 2 diberi dosis ekstrak 140 mg/200 gram BB/hari, dan kelompok perlakuan 3 diberi dosis ekstrak 210 mg/200 gram BB/hari. Pada hari ke-22, dilakukan pengambilan darah dari pleksus preorbitalis untuk pengukuran kadar trigliserida. Kemudian data dianalisis menggunakan uji One-way ANOVA, kemudian dilanjutkan uji Least Significance Difference (LSD). Hasil Penelitian : Analisis statistik dengan menggunakan uji One-way ANOVA menunjukkan bahwa terdapat perbedaan kadar trigliserida yang bermakna antara keenam kelompok perlakuan (p = 0,001). Uji Post Hoc menunjukkan bahwa terdapat perbedaan bermakna antarpasangan kelompok perlakuan, kecuali kelompok perlakuan 3 dengan hasil yang mendekati kelompok kontrol positif (p = 0,768). Simpulan Penelitian : Pemberian ekstrak Bengkuang (Pachyrhizus erosus) dapat menurunkan kadar trigliserida darah tikus putih secara signifikan. Kata kunci: Ekstrak Bengkuang (Pachyrhizus erosus), kadar trigliserida, tikus putih
