N‐Carboxymethylchitosan enhancement of the storage protein contents of maize seeds (<i>Zea mays L</i>.)

Osuji, Godson O.; Cuero, R. G.

doi:10.1080/08905439209549826

Cited by 8 publications

(5 citation statements)

References 23 publications

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“…The results of the GDH subunit patterns presented are those with the neatest resolution of the degraded polypeptides from the undegraded subunits of the enzyme. The GDH band intensities were estimated by densitometry (Osuji and Cuero, 1992).…”

Section: Introductionmentioning

confidence: 99%

Pesticide Inactivation of Peanut Glutamate Dehydrogenase: Biochemical Basis of the Enzyme's Isomerization

Osuji

Braithwaite

Pointer

1999

J. Agric. Food Chem.

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Glutamate dehydrogenase (GDH) isomerizes in response to pesticides and environmental chemicals, but the biochemical basis of the isomerization is not known. Clearer understanding of the isomerization would permit expansion of its utility in the diagnosis of the responses of plant tissues to challenged environments. Peanut plants were treated with different rates of Basagran (3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide), Bravo 720 (tetrachloroiso-phthalonitrile), and Sevin XLR Plus (1-naphthyl N-methylcarbamate). Free solution isoelectric focusing, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) fractionated the peanut seed GDH to its constituent subunits and degradation polypeptides. After western transfer to nitrocellulose membrane, the GDH subunits and degradation polypeptides were immunodetected with anti-GDH. The pesticide treatments did not induce increased proteolytic activity, but induced about 50% degradation of the GDH, whereas the GDH of the control peanut suffered only about 25% degradation, thus showing that the degradation rate was about double the rate of de novo synthesis in the pesticide treatments. The heavy displacement of the GDH subunit equilibrium toward degradation explains the biochemical basis of the isomerization reaction.

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Section: Introductionmentioning

confidence: 99%

Pesticide Inactivation of Peanut Glutamate Dehydrogenase: Biochemical Basis of the Enzyme's Isomerization

Osuji

Braithwaite

Pointer

1999

J. Agric. Food Chem.

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“…Whereas the Biuret and Kjeldahl analyses demonstrated that total soluble proteins were increased in the NCMC-treated crops (Table 111, the densitometric analyses following the PAGE of the proteins permitted the quantitation of the percentages of the major storage proteins in the crops. NCMC treatment of corn seedlings germinating at different temperatures, however, enhanced the concentrations of the zeins and also altered the ratios between the different zein polypeptides (Osuji and Cuero, 1991a). NCMC treatment of corn seedlings germinating at different temperatures, however, enhanced the concentrations of the zeins and also altered the ratios between the different zein polypeptides (Osuji and Cuero, 1991a).…”

Section: Regulation Of Nh4+ Ion Salvage By Ncmc Application To Cropsmentioning

confidence: 94%

“…To probe the molecular basis of the effects of NCMC on storage proteins, the mRNA contents of NCMC-treated corn were found to be increased (Osuji and Cuero, 1991a). This suggests that NCMC enhanced transcription, thereby providing more storage protein mRNA.…”

Section: Regulation Of Nh4+ Ion Salvage By Ncmc Application To Cropsmentioning

confidence: 99%

“…The inhibition renders the protein-deficient crops inefficient in ammonium ion salvage, the evidence for which is the loss of ammonia by the crops during postharvest storage (Osuji andOry, 1986,1987). It has also been used to double the storage protein contents of corn (Osuji and Cuero, 1991a). (NCMC) is a derivative of the naturally occurring polysaccharide chitosan.…”

Section: Introductionmentioning

confidence: 99%

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Regulation of ammonium ion salvage and enhancement of the storage protein contents of corn, sweet potato, and yam tuber by N-(carboxymethyl)chitosan application

Osuji¹,

Cuero²

1992

J. Agric. Food Chem.

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The biochemical approach to storage protein enhancement via NH4+ ion metabolism was investigated by treatment of growing yam tuber, sweet potato, and corn with N-(carboxymethy1)chitosan (NCMC). Application of NCMC to yam tuber gave rise to a-ketoglutarate (aKG)-dependent inhibition of the glutamate synthase (GOGAT) with an inhibition constant (Ki) of 3 mM but relieved the aKG-dependent inhibition of the glutamate dehydrogenase (GDH), with a concomitant 270% increase of the storage protein content. In sweet potato, NCMC application gave rise to glutamate-dependent inhibition of the glutamine synthetase (GS) with Ki of 15 mM but relieved the inhibition of the GDH by high aKG concentrations, with a concomitant doubling of the storage protein contents. In corn, NCMC application also gave rise to aKG-dependent inhibition of the GOGAT with Ki of 0.5 mM but relieved the aKGdependent inhibition of the GDH, with a concomitant doubling of the storage protein content. NCMC treatment also reduced the levels of some of the high molecular weight polypeptides (deaminating) while it increased the levels of some of the low molecular weight polypeptides (aminating) of GDH. Therefore, NCMC enhanced the storage protein contents of the crops by enhancing NH4+ ion salvage.

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“…Therefore, the non-exergonic reaction steps in glycolysis and citricglyoxylic acid cycle constitute the biochemical mechanisms that improve the nutritious EAA quality of plant proteins. This is a new and simple plant sciences-based biotechnology compared with earlier ones [2] [17] because it doubles the biosynthesis of EAAs at the whole plant level. An advantage of this biotechnology is that it could be limited resource-farmer friendly, empowering family-owned gardens to produce EAA nutritious food crops.…”

Section: Molecular Regulation Of Essential Amino Acid Biosynthesismentioning

confidence: 99%

Enhancement of the Essential Amino Acid Composition of Food Crop Proteins through Biotechnology

Osuji

Duffus

Johnson

et al. 2015

AJPS

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Lack of essential amino acids (EAA) in the diet of at-risk populations could beget a state of food insecurity. Plant proteins are deficient in some essential amino acids. Animals obtain EAA from plant sources. Simple biotechnologies are being developed for improving the EAA composition of crop proteins. The aim was to integrate-discriminate glycolysis and citric-glyoxylic acid cycles to optimize biosynthesis of EAA in food crops. Permutation of diverse metabolic pathways at the mRNA level by glutamate dehydrogenase (GDH)-synthesized RNA is a common biotechnology for doubling the nutritious compositions of plants. Peanuts were planted in plots and treated with mineral salts mixed according to stoichiometric ratios. Protein-bounded and free amino acids of mature peanut seeds were determined by HPLC. GDH-synthesized RNA probes homologous to the mRNAs encoding glyceraldehyde-3-phosphate dehydrogenase (GAPDH), phosphoglycerate mutase (PGlycM), phosphoenolpyruvate carboxylase (PEPCase), enolase, malate dehydrogenase (MDH), isocitrate lyase (ICL), and malate synthase (MS) were prepared from peanut seeds using restriction fragment double differential display PCR method. Northern assays of peanut total RNA showed that the mRNAs encoding PGlycM, PEPCase, MDH, and MS shared extensive sequence homologies that produced a dense network of cross-talks, resulting to co-differential silencing of the mRNAs thereby permuting glycolysis, citric-glyoxylic acid cycles. There were 42 permutations in the NPPKtreated, 105 in control, 420 in KN-, and NPKS-treated peanuts. Because of permutations involving the mRNAs encoding ICL and MS, wherever the abundances of these mRNAs were high (control, and NPPK-treated peanuts) the concentrations of the α-ketoglutarate group of total glutamate, glutamine, arginine, proline, and histidine were minimized (<7.0 mg/g) but the concentrations of the oxaloacetate group of total aspartate, lysine, methionine, threonine, and isoleucine were maxi-* Corresponding author. G. O. Osuji et al.3092 mized (>28.0 mg/g). The integration of glycolysis, citric and glyoxylic acid cycles increased the quality and doubled the concentrations of the protein-bounded EAA composition of NPPK-treated (33.37 mg/g) compared with the control peanut (15.66 mg/g). The commanding biotechnology was the stoichiometric mineral salts-based induction of GDH to synthesize the RNAs that integrated glycolysis, citric-glyoxylic acid cycles to one functional unit.

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N‐Carboxymethylchitosan enhancement of the storage protein contents of maize seeds (Zea mays L.)

Cited by 8 publications

References 23 publications

Pesticide Inactivation of Peanut Glutamate Dehydrogenase: Biochemical Basis of the Enzyme's Isomerization

Pesticide Inactivation of Peanut Glutamate Dehydrogenase: Biochemical Basis of the Enzyme's Isomerization

Regulation of ammonium ion salvage and enhancement of the storage protein contents of corn, sweet potato, and yam tuber by N-(carboxymethyl)chitosan application

Enhancement of the Essential Amino Acid Composition of Food Crop Proteins through Biotechnology

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