Phyla (Lippia) dulcis contains hernundulcin sesquiterpene zero-caloric sweetener that is about a thousand times sweeter than sucrose, and also bitter constituents including camphor and limonene. There is yet no simple...Phyla (Lippia) dulcis contains hernundulcin sesquiterpene zero-caloric sweetener that is about a thousand times sweeter than sucrose, and also bitter constituents including camphor and limonene. There is yet no simple method to remove the undesirable constituents. The yield of sweetener hernundulcin is very low, and there is no simple method to maximize its composition. The aim of the project was to characterize the mRNA targets that regulate the primary and terpenoid metabolic enzymes of P. dulcis. Restriction fragment differential display polymerase chain reaction of P. dulcis glutamate dehydrogenase-synthesized RNA showed that many mRNAs encoding β-caryophyllene, (+)-epi-α-bisabolol, bicyclogermacrene, bifunctional sesquiterpene, and geraniol synthases shared sequence homologies with ribulose-1,5-bisphophatase carboxylase, granule-bound starch synthase, pyruvate kinase, glucose-6-phosphate dehydrogenase, and phosphoenol pyruvate carboxylase. Sequence similarities between mRNAs encoding primary metabolic enzymes and terpene synthases suggested that photosynthesis could regulate terpenoid metabolism in order to increase the yield of sweetener hernundulcin.展开更多
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 ...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 maximized (>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.展开更多
文摘Phyla (Lippia) dulcis contains hernundulcin sesquiterpene zero-caloric sweetener that is about a thousand times sweeter than sucrose, and also bitter constituents including camphor and limonene. There is yet no simple method to remove the undesirable constituents. The yield of sweetener hernundulcin is very low, and there is no simple method to maximize its composition. The aim of the project was to characterize the mRNA targets that regulate the primary and terpenoid metabolic enzymes of P. dulcis. Restriction fragment differential display polymerase chain reaction of P. dulcis glutamate dehydrogenase-synthesized RNA showed that many mRNAs encoding β-caryophyllene, (+)-epi-α-bisabolol, bicyclogermacrene, bifunctional sesquiterpene, and geraniol synthases shared sequence homologies with ribulose-1,5-bisphophatase carboxylase, granule-bound starch synthase, pyruvate kinase, glucose-6-phosphate dehydrogenase, and phosphoenol pyruvate carboxylase. Sequence similarities between mRNAs encoding primary metabolic enzymes and terpene synthases suggested that photosynthesis could regulate terpenoid metabolism in order to increase the yield of sweetener hernundulcin.
文摘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 maximized (>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.
