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Desh Pal S Verma - One of the best experts on this subject based on the ideXlab platform.

  • removal of feedback inhibition of δ1 pyrroline 5 carboxylate synthetase results in increased proline accumulation and protection of plants from osmotic stress
    Plant Physiology, 2000
    Co-Authors: Zonglie Hong, Karuna Lakkineni, Zhongming Zhang, Desh Pal S Verma
    Abstract:

    The Δ1-pyrroline-5-carboxylate synthetase (P5CS; EC not assigned) is the rate-limiting enzyme in proline (Pro) biosynthesis in plants and is subject to feedback inhibition by Pro. It has been suggested that the feedback regulation of P5CS is lost in plants under stress conditions. We compared Pro levels in transgenic tobacco (Nicotiana tabacum) plants expressing a wild-type form of Vigna aconitifolia P5CS and a mutated form of the enzyme (P5CSF129A) whose feedback inhibition by Pro was removed by site-directed mutagenesis. Transgenic plants expressing P5CSF129A accumulated about 2-fold more Pro than the plants expressing V. aconitifolia wild-type P5CS. This difference was further increased in plants treated with 200 mm NaCl. These results demonstrated that the feedback regulation of P5CS plays a role in controlling the level of Pro in plants under both normal and stress conditions. The elevated Pro also reduced free radical levels in response to osmotic stress, as measured by malondialdehyde production, and significantly improved the ability of the transgenic seedlings to grow in medium containing up to 200 mm NaCl. These findings shed new light on the regulation of Pro biosynthesis in plants and the role of Pro in reducing oxidative stress induced by osmotic stress, in addition to its accepted role as an osmolyte.

  • overexpression of a δ1 pyrroline 5 carboxylate synthetase gene and analysis of tolerance to water and salt stress in transgenic rice
    Plant Science, 1998
    Co-Authors: Baocheng Zhu, Desh Pal S Verma, Jin Su, Menchi Chang, Yunliu Fan, Ray Wu
    Abstract:

    Abstract A Δ 1 -pyrroline-5-carboxylate synthetase (P5CS) cDNA from mothbean ( Vigna aconitifolia L.) was introduced into rice ( Oryza sativa L.) genome by the biolistic method. Expression of this P5CS transgene under the control of a stress-inducible promoter led to stress-induced overproduction of the P5CS enzyme and proline accumulation in transgenic rice plants. Second-generation (R 1 ) transgenic rice plants showed an increase in biomass under salt-stress and water-stress conditions as compared to the non-transformed control plants.

  • structural organization of de novo purine biosynthesis enzymes in plants 5 aminoimidazole ribonucleotide carboxylase and 5 aminoimidazole 4 n succinocarboxamide ribonucleotide synthetase cdnas from Vigna aconitifolia
    Plant Molecular Biology, 1994
    Co-Authors: Kenneth A Chapman, Ashton J Delauney, Jong H Kim, Desh Pal S Verma
    Abstract:

    Nodules of tropical legumes generally export symbiotically fixed nitrogen in the form of ureides that are produced by oxidation of de novo synthesized purines. To investigate the regulation of de novo purine biosynthesis in these nodules, we have isolated cDNA clones encoding 5-aminoimidazole ribonucleotide (AIR) carboxylase and 5-aminoimidazole-4-N-succinocarboxamide ribonucleotide (SAICAR) synthetase from a mothbean (Vigna aconitifolia) nodule cDNA library by complementation of Escherichia coli purE and purC mutants, respectively. Sequencing of these clones revealed that the two enzymes are distinct proteins in mothbean, unlike in animals where both activities are associated with a single bifunctional polypeptide. As is the case in yeast, the mothbean AIR carboxylase has a N-terminal domain homologous to the eubacterial purK gene product. This PurK-like domain appears to facilitate the binding of CO2 and is dispensable in the presence of high CO2 concentrations. Because the expression of the mothbean PurE cDNA clone in E. coli apparently generates a truncated polypeptide lacking at least 140 N-terminal amino acids, this N-terminal region of the enzyme may not be essential for its CO2-binding activity.

  • cloning of ornithine delta aminotransferase cdna from Vigna aconitifolia by trans complementation in escherichia coli and regulation of proline biosynthesis
    Journal of Biological Chemistry, 1993
    Co-Authors: A J Delauney, P B Kishor, Desh Pal S Verma
    Abstract:

    Abstract Proline prototrophy was restored to an Escherichia coli proBA proline auxotroph by ornithine and a mothbean (Vigna aconitifolia) cDNA expression library. This novel strategy, "trans-complementation," allowed isolation of a cDNA encoding ornithine delta-aminotransferase (delta-OAT). This enzyme transaminates ornithine to glutamic-gamma-semialdehyde (GSA), thereby bypassing the block in GSA synthesis from glutamate in the proBA mutant. The identity of the mothbean enzyme was confirmed by its high sequence homology to mammalian and yeast delta-OATs as well as to a family of bacterial and fungal omega-aminotransferases and an absence of significant homology to various alpha-aminotransferases. The V. aconitifolia OAT cDNA encodes a polypeptide of 48.1 kDa. The native enzyme expressed in E. coli appears to be a monomer with Km of 2 mM for ornithine and 0.75 mM for alpha-ketoglutarate. Levels of mRNA in V. aconitifolia for delta 1-pyrroline-5-carboxylate synthetase (P5CS) and delta-OAT, the two key enzymes for proline synthesis, were monitored under different physiological conditions. Salt stress and nitrogen starvation induced P5CS mRNA levels and depressed OAT mRNA levels. Conversely, OAT mRNA level was elevated in plants supplied with excess nitrogen while the P5CS mRNA level was reduced. These data suggest that the glutamate pathway is the primary route for proline synthesis in plants during conditions of osmotic stress and nitrogen limitation whereas the ornithine pathway assumes prominence under high nitrogen input.

  • expression of antisense nodulin 35 rna in Vigna aconitifolia transgenic root nodules retards peroxisome development and affects nitrogen availability to the plant
    Plant Journal, 1993
    Co-Authors: Nagyong Lee, Barry Stein, Hideki Suzuki, Desh Pal S Verma
    Abstract:

    A nodulin-35 (N-35) cDNA encoding nodule-specific uricase (EC 1.7.3.3.) was isolated from a Vigna aconitifolia (mothbean) root nodule cDNA library. Sequence analysis of Vigna uricase (VN-35) cDNA revealed 90% homology to that of soybean. The VN-35 cDNA was inserted in the antisense orientation downstream of the caMV-35S promoter, and transgenic hairy roots were formed on Vigna plants using Agrobacterium rhizogenes. Infection with Bradyrhizobium (cowpea) gave rise to root nodules on transgenic hairy roots supported by the wild-type shoot. Expression of antisense VN-35 RNA was detected in transgenic nodules on individual roots using polymerase chain reaction (PCR). The nodules expressing antisense VN-35 RNA were smaller in size and showed lower uricase activity than nodules formed on the hairy roots transformed with a binary vector containing beta-glucuronidase (GUS) gene (used as control), and the plants exhibited nitrogen deficiency symptoms. Ultrastructural analysis and immunogold labeling with antibody against soybean N-35 revealed that the growth of peroxisomes was retarded in transgenic nodules expressing antisense VN-35 RNA. These data suggest that a reduction in ureide biosynthesis limits the availability of symbiotically reduced nitrogen to the plant. The nodules of tropical legumes appear to be specialized in nitrogen assimilation and are developmentally controlled to produce and transport ureides.

Raj Kumar - One of the best experts on this subject based on the ideXlab platform.

  • Moth bean starch (Vigna aconitifolia): isolation, characterization, and development of edible/biodegradable films
    Journal of Food Science and Technology, 2019
    Co-Authors: Raj Kumar, Gargi Ghoshal, Meenakshi Goyal
    Abstract:

    In the current work, moth bean starch was separated from the moth bean seeds which were cultivated in the semi arid regions of Haryana and Rajasthan, India using alkali treatment technique and characterized. Isolated and purified moth bean starch comprised (12.89–20.37%) amylose, 0.8% protein, 0.4% ash, swelling index and solubility were 10.8–14.7% and 6.4–9.8% respectively. For wrapping application, starch was modified using citric acid as cross linking agent (1–7% w/w of total starch) and film was made using casting method, and investigated the influence of citric acid on the functional properties of the films such as moisture content, solubility, swelling index, water vapor permeability and mechanical property. Significant difference in the functional properties among native and modified moth bean starch films was noticed. Interactions among starch chains due to cross linking in the modified starch films were reported using FTIR spectra. Surface micrographs of both purfied starch granules and films were studied using scanning electron microscopy. From the outcomes, it was exhibited that obtained starch granules has range large to small size with distorted cylinder and oval shapes. While cross linked starch films showed compact, slightly rough and homogeneous surface. Tested modified moth bean starch films containing citric acid (CA) and sorbitol were utilized as wrapping films to improve the shelf life of fresh lemon. Outcomes showed that the film contains 5% CA could be most promising wrapping materials for lemon that enhanced the shelf life of lemon additionally up to 12 days.

  • moth bean starch Vigna aconitifolia isolation characterization and development of edible biodegradable films
    Journal of Food Science and Technology-mysore, 2019
    Co-Authors: Gargi Ghoshal, Raj Kumar, Meenakshi Goyal
    Abstract:

    In the current work, moth bean starch was separated from the moth bean seeds which were cultivated in the semi arid regions of Haryana and Rajasthan, India using alkali treatment technique and characterized. Isolated and purified moth bean starch comprised (12.89-20.37%) amylose, 0.8% protein, 0.4% ash, swelling index and solubility were 10.8-14.7% and 6.4-9.8% respectively. For wrapping application, starch was modified using citric acid as cross linking agent (1-7% w/w of total starch) and film was made using casting method, and investigated the influence of citric acid on the functional properties of the films such as moisture content, solubility, swelling index, water vapor permeability and mechanical property. Significant difference in the functional properties among native and modified moth bean starch films was noticed. Interactions among starch chains due to cross linking in the modified starch films were reported using FTIR spectra. Surface micrographs of both purfied starch granules and films were studied using scanning electron microscopy. From the outcomes, it was exhibited that obtained starch granules has range large to small size with distorted cylinder and oval shapes. While cross linked starch films showed compact, slightly rough and homogeneous surface. Tested modified moth bean starch films containing citric acid (CA) and sorbitol were utilized as wrapping films to improve the shelf life of fresh lemon. Outcomes showed that the film contains 5% CA could be most promising wrapping materials for lemon that enhanced the shelf life of lemon additionally up to 12 days.

Meenakshi Goyal - One of the best experts on this subject based on the ideXlab platform.

  • Moth bean starch (Vigna aconitifolia): isolation, characterization, and development of edible/biodegradable films
    Journal of Food Science and Technology, 2019
    Co-Authors: Raj Kumar, Gargi Ghoshal, Meenakshi Goyal
    Abstract:

    In the current work, moth bean starch was separated from the moth bean seeds which were cultivated in the semi arid regions of Haryana and Rajasthan, India using alkali treatment technique and characterized. Isolated and purified moth bean starch comprised (12.89–20.37%) amylose, 0.8% protein, 0.4% ash, swelling index and solubility were 10.8–14.7% and 6.4–9.8% respectively. For wrapping application, starch was modified using citric acid as cross linking agent (1–7% w/w of total starch) and film was made using casting method, and investigated the influence of citric acid on the functional properties of the films such as moisture content, solubility, swelling index, water vapor permeability and mechanical property. Significant difference in the functional properties among native and modified moth bean starch films was noticed. Interactions among starch chains due to cross linking in the modified starch films were reported using FTIR spectra. Surface micrographs of both purfied starch granules and films were studied using scanning electron microscopy. From the outcomes, it was exhibited that obtained starch granules has range large to small size with distorted cylinder and oval shapes. While cross linked starch films showed compact, slightly rough and homogeneous surface. Tested modified moth bean starch films containing citric acid (CA) and sorbitol were utilized as wrapping films to improve the shelf life of fresh lemon. Outcomes showed that the film contains 5% CA could be most promising wrapping materials for lemon that enhanced the shelf life of lemon additionally up to 12 days.

  • moth bean starch Vigna aconitifolia isolation characterization and development of edible biodegradable films
    Journal of Food Science and Technology-mysore, 2019
    Co-Authors: Gargi Ghoshal, Raj Kumar, Meenakshi Goyal
    Abstract:

    In the current work, moth bean starch was separated from the moth bean seeds which were cultivated in the semi arid regions of Haryana and Rajasthan, India using alkali treatment technique and characterized. Isolated and purified moth bean starch comprised (12.89-20.37%) amylose, 0.8% protein, 0.4% ash, swelling index and solubility were 10.8-14.7% and 6.4-9.8% respectively. For wrapping application, starch was modified using citric acid as cross linking agent (1-7% w/w of total starch) and film was made using casting method, and investigated the influence of citric acid on the functional properties of the films such as moisture content, solubility, swelling index, water vapor permeability and mechanical property. Significant difference in the functional properties among native and modified moth bean starch films was noticed. Interactions among starch chains due to cross linking in the modified starch films were reported using FTIR spectra. Surface micrographs of both purfied starch granules and films were studied using scanning electron microscopy. From the outcomes, it was exhibited that obtained starch granules has range large to small size with distorted cylinder and oval shapes. While cross linked starch films showed compact, slightly rough and homogeneous surface. Tested modified moth bean starch films containing citric acid (CA) and sorbitol were utilized as wrapping films to improve the shelf life of fresh lemon. Outcomes showed that the film contains 5% CA could be most promising wrapping materials for lemon that enhanced the shelf life of lemon additionally up to 12 days.

Manikandan Ramesh - One of the best experts on this subject based on the ideXlab platform.

  • Transgenic indica rice cv. ADT 43 expressing a Δ^1-pyrroline-5-carboxylate synthetase (P5CS) gene from Vigna aconitifolia demonstrates salt tolerance
    Plant Cell Tissue and Organ Culture (PCTOC), 2011
    Co-Authors: Alagarsamy Karthikeyan, Shumugiah Karutha Pandian, Manikandan Ramesh
    Abstract:

    To develop salt tolerant rice, the P5CS gene of Vigna aconitifolia , encoding for proline synthesis, was introduced into the popular indica rice cultivar ADT 43. Agrobacterium tumefaciens strain LBA 4404 harboring the binary vector pCAMBIA 1301/P5CS, carrying the proline synthesis encoding gene P5CS , was co-cultivated with embryogenic callus of rice. Adding 100 μM acetosyringone to the Linsmaier and Skoog (LS) liquid and solid co-culture medium, along with 30 mg/l hygromycin and 250 mg/l timentin, contributed to significantly higher efficiency of transformation. Southern blot analysis of T_1 independent transformants revealed that the copy number of transgene varied between one and three. When transgenic plants were subjected to salt stress, these plants grew well in the presence of up to 200 mM NaCl, while control plants died within 10 days under these treatment conditions. These transgenic plants grew under salt stress for a period of 4 weeks, and were capable of flowering and set seed. T_1 plants segregated into 3:1 ratio suggesting Mendelian segregation pattern of inheritance of the P5CS transgene.

Luiz Gonzaga Esteves Vieira - One of the best experts on this subject based on the ideXlab platform.

  • Effects of high proline accumulation on chloroplast and mitochondrial ultrastructure and on osmotic adjustment in tobacco plants
    Eduem (Editora da Universidade Estadual de Maringá), 2015
    Co-Authors: Lucélia Borgo, Celso Jamil Marur, Luiz Gonzaga Esteves Vieira
    Abstract:

    Proline accumulates in many organisms in response to abiotic stresses, such as drought and salinity. Reports have discussed the role of proline in relation to osmotic adjustment, even though no clear-cut evidence has yet been provided demonstrating this association as a defense mechanism against drought stress in plants. However, it has been indicated that the application of exogenous proline can damage the ultrastructure of chloroplasts and mitochondria. In this study, using transgenic tobacco plants carrying a mutant p5cs gene from Vigna aconitifolia under control of the CaMV 35S promoter, we show that the high levels of endogenous proline accumulated in leaves does not contribute to the osmotic adjustment in plants under water deficit conditions. Additionally, electron microscopic observations of mitochondria and chloroplasts show that the ultrastructure of these organelles was not damaged even in the transgenic plants, with the leaves presenting the highest endogenous proline content in (100 µmol g-1 dry mass). This investigation demonstrates that in tobacco, high levels of endogenous free proline are not associated with osmotic adjustment and that elevated proline content in leaves, even at levels 10 times higher than normal, do not disturb the chloroplast and mitochondria ultrastructure under both irrigated and water deficit conditions

  • Stress-induced Δ1-pyrroline-5-carboxylate synthetase (P5CS) gene confers tolerance to salt stress in transgenic sugarcane
    Acta Physiologiae Plantarum, 2014
    Co-Authors: Julia Tufino Silva Guerzoni, Nathalia Geraldo Belintani, Rosangela Maria Pinto Moreira, Andrea Akemi Hoshino, Douglas Silva Domingues, João Carlos Bespalhok Filho, Luiz Gonzaga Esteves Vieira
    Abstract:

    High salinity interferes in sugarcane growth and development, affecting not only crop yield but also reducing sucrose concentration in culms. Sugarcane plants submitted to salt stress can accumulate compatible solutes, such as proline, which may counteract the effects of salt accumulation in the vacuole and scavenge reactive oxygen species. The objective of this study was to evaluate the response to salt stress of sugarcane plants transformed with the Vigna aconitifolia P5CS gene, which encodes ∆1-pyrroline-5-carboxylate synthetase, under the control of a stress-induced promoter AIPC ( ABA-inducible promoter complex ). For this, 4-month-old clonally multiplied sugarcane plants from two transformation events were irrigated every 2 days with 1/10 Hoagland’s solution supplemented with 100, 150 and 200 NaCl, progressively, during 28 days. Transgenic lines showed increased transgene expression in 3.75-fold when compared with the control plants after 9 days of irrigation with saline water, which can explain the higher proline concentration found in these plants. At the end of the experiment (day 28), the transgenic lines accumulated up to 25 % higher amounts of proline when compared with non-transformed control plants. Stress response in transgenic plants was also accompanied by a reduction of malondialdehyde (MDA) derived from cellular lipid peroxidation in leaves, lower Na^+ accumulation in leaves and maintenance of photochemical efficiency of PSII. Thus, proline contributed to the protection of the photosynthetic apparatus and the prevention of oxidative damage in transgenic sugarcane under salt stress.

  • stress induced synthesis of proline confers tolerance to water deficit in transgenic wheat
    Journal of Plant Physiology, 2007
    Co-Authors: Eliane Cristina Gruszka Vendruscolo, Ivan Schuster, Marcos Pileggi, Carlos Alberto Scapim, Hugo Bruno Correa Molinari, Celso Jamil Marur, Luiz Gonzaga Esteves Vieira
    Abstract:

    Summary Water deficit is one of the main abiotic factors that affect spring wheat planted in subtropical regions. Accumulation of proline appears to be a promising approach to maintain the productivity of plants under stress condition. However, morphological alterations and growth reduction are observed in transgenic plants carrying genes coding for osmoprotectants controlled by constitutive promoters. We report here the effects of water deficit on wheat plants transformed with the Vigna aconitifolia Δ 1 -pyrroline-5-carboxylate synthetase ( P5CS ) cDNA that encodes the key regulatory enzyme in proline biosynthesis, under the control of a stress-induced promoter complex—AIPC. Transgenic wheat plants submitted to 15 days of water shortage presented a distinct response. We have found that drought resulted in the accumulation of proline. The tolerance to water deficit observed in transgenic plants was mainly due to protection mechanisms against oxidative stress and not caused by osmotic adjustment.

  • stress induced synthesis of proline confers tolerance to water deficit in transgenic wheat
    Journal of Plant Physiology, 2007
    Co-Authors: Eliane Cristina Gruszka Vendruscolo, Ivan Schuster, Marcos Pileggi, Carlos Alberto Scapim, Hugo Bruno Correa Molinari, Celso Jamil Marur, Luiz Gonzaga Esteves Vieira
    Abstract:

    Water deficit is one of the main abiotic factors that affect spring wheat planted in subtropical regions. Accumulation of proline appears to be a promising approach to maintain the productivity of plants under stress condition. However, morphological alterations and growth reduction are observed in transgenic plants carrying genes coding for osmoprotectants controlled by constitutive promoters. We report here the effects of water deficit on wheat plants transformed with the Vigna aconitifolia Delta(1)-pyrroline-5-carboxylate synthetase (P5CS) cDNA that encodes the key regulatory enzyme in proline biosynthesis, under the control of a stress-induced promoter complex-AIPC. Transgenic wheat plants submitted to 15 days of water shortage presented a distinct response. We have found that drought resulted in the accumulation of proline. The tolerance to water deficit observed in transgenic plants was mainly due to protection mechanisms against oxidative stress and not caused by osmotic adjustment.