Screening and Breeding for Biofortification of Rice with Protein and High Lysine Contents

Comparative Proteome-wide Characterization of Three Different Tissues of High-Protein Mutant and Wild Type Unravels Protein Accumulation Mechanisms in Rice Seeds

“…In addition to these enzymes involved in the biosynthesis of essential amino acids, several other enzymes associated with the metabolism of non-essential amino acids were also identified in this study (Table S4 and Figure 5A). Although the contents of non-essential amino acids including cysteine, asparagine, glutamine, and alanine were not evaluated in our previous study, 6 the identification of their associated enzymes indicates a difference in their contents between WT and HPM seeds. For instance, asparagine synthetase and glutamine synthetase, the key enzymes of asparagine and glutamine biosynthetic pathways, respectively, were increased in the HPM seed, indicating a higher accumulation of both of these amino acids in the HPM seed.…”

“…There were no obvious differences in the phenological features of matured WT and HPM seeds (Figure 1A); however, they varied drastically in their total protein and amino acid contents (data not shown). 6 The total protein content of the WT seed was 9.3%, while that of the HPM seed was 14.8% (Figure 1B). Proteins isolated from the embryo, endosperm, and bran samples of WT and HPM seeds using phenol and TCA/acetone precipitation methods showed clear separation on SDS-PAGE (Figure S1).…”

“…indica, Dharial) seeds, originating in Bangladesh, were obtained and used in this study as reported previously. 6 For the generation of mutagenized populations, dried rice seeds were treated with 1.5% EMS as described in detail before. 23 M 1 plants so obtained were self-fertilized to generate M 2 plants which were continuously self-fertilized again through the single seed descent (SSD) method until M 6 generation.…”

“…In addition, this HPM seed also exhibited an almost 2-fold enhanced accumulation of other essential amino acids such as threonine, leucine, isoleucine, phenylalanine, valine, and histidine. 6 However, mechanisms underlying this higher protein and (including essential) amino acid accumulation in the HPM as compared to its parent WT remain to be investigated.…”

“…Recently, we generated several ethyl methanesulfonate (EMS) mutants of an indica rice “Dharial (wild-type; WT)” of which line C-162 showed the highest total protein and total amino acid contents along with an almost 5-fold increased accumulation of the essential amino acid lysine than its parent WT, which is originating in Bangladesh . The reported protein contents in WT and its EMS mutant (high-protein mutant; HPM) seeds are 9.3 and 14.8%, respectively, while their lysine contents were 0.8 and 3.75 mg/g, respectively.…”