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

Abstract

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.