Rice is the primary staple food for half of the world's population but is low in lysine content. Previously, we developed transgenic rice with enhanced free lysine content in rice seeds (lysine-rich rice), which was shown safe for consumption and improved the growth in rats. However, the effects of lysine-rich rice on skeletal growth and development remained unknown.
View Article and Find Full Text PDFCrop biofortification is pivotal in preventing malnutrition, with lysine considered the main limiting essential amino acid (EAA) required to maintain human health. Lysine deficiency is predominant in developing countries where cereal crops are the staple food, highlighting the need for efforts aimed at enriching the staple diet through lysine biofortification. Successful modification of aspartate kinase (AK) and dihydrodipicolinate synthase (DHDPS) feedback inhibition has been used to enrich lysine in transgenic rice plants without yield penalty, while increases in the lysine content of quality protein maize have been achieved via marker-assisted selection.
View Article and Find Full Text PDFLysine is the main limiting essential amino acid (EAA) in the rice seeds, which is a major energy and nutrition source for humans and livestock. In higher plants, the rate-limiting steps in lysine biosynthesis pathway are catalysed by two key enzymes, aspartate kinase (AK) and dihydrodipicolinate synthase (DHDPS), and both are extremely sensitive to feedback inhibition by lysine. In this study, two rice AK mutants (AK1 and AK2) and five DHDPS mutants (DHDPS1-DHDPS5), all single amino acid substitution, were constructed.
View Article and Find Full Text PDFCereal endosperms produce a vast array of metabolites, including the essential amino acid lysine (Lys). Enhanced accumulation of Lys has been achieved via metabolic engineering in cereals, but the potential connection between metabolic engineering and Lys fortification is unclear. In mature seeds of engineered High Free Lysine (HFL) rice (), the endosperm takes on a characteristic dark-brown appearance.
View Article and Find Full Text PDFLysine is the first limiting essential amino acid in rice. We previously constructed a series of transgenic rice lines to enhance lysine biosynthesis (35S), down-regulate its catabolism (Ri), or simultaneously achieve both metabolic effects (35R). In this study, nine transgenic lines, three from each group, were selected for both field and animal feeding trials.
View Article and Find Full Text PDFRice is an excellent source of protein, and has an adequate balance of amino acids with the exception of the essential amino acid lysine. By using a combined enhancement of lysine synthesis and suppression of its catabolism, we had produced two transgenic rice lines HFL1 and HFL2 (High Free Lysine) containing high concentration of free lysine. In this study, a 70-day rat feeding study was conducted to assess the nutritional value of two transgenic lines as compared with either their wild type (WT) or the WT rice supplemented with different concentrations of L-lysine.
View Article and Find Full Text PDFLysine is considered to be the first essential amino acid in rice. An elite High-Free-Lysine transgenic line HFL1 was previously produced by metabolic engineering to regulate lysine metabolism. In this study, a 90-day toxicology experiment was undertaken to investigate the potential health effect of feeding different doses of HFL1 rice to Sprague-Dawley rats.
View Article and Find Full Text PDFRice (Oryza sativa L.), a major staple crop worldwide, has limited levels of the essential amino acid lysine. We previously produced engineered rice with increased lysine content by expressing bacterial aspartate kinase and dihydrodipicolinate synthase and inhibiting rice lysine ketoglutarate reductase/saccharopine dehydrogenase activity.
View Article and Find Full Text PDFSlPAP1 is a phosphate starvation responsive purple acid phosphatase during tomato seed germination. Future research on its family members in tomato might improve the phosphate stress tolerance. Phosphate deficiency is a major constraint upon crop growth and yield.
View Article and Find Full Text PDFFood supply and food safety are major global public health issues, and are particularly important in heavily populated countries such as China. Rapid industrialisation and modernisation in China are having profound effects on food supply and food safety. In this Review, we identified important factors limiting agricultural production in China, including conversion of agricultural land to other uses, freshwater deficits, and soil quality issues.
View Article and Find Full Text PDFLarge-scale protein phosphorylation analysis by MS is emerging as a powerful tool in plant signal transduction research. However, our current understanding of the phosphorylation regulatory network in plants is still very limited. Here, we report on a proteome-wide profiling of phosphopeptides in nine-day-old Arabidopsis (Arabidopsis thaliana) seedlings by using an enrichment method combining the titanium (Ti(4+))-based IMAC and the RP-strong cation exchange (RP-SCX) biphasic trap column-based online RPLC.
View Article and Find Full Text PDFNitrogen (N) is an important nutrient and signal for plant growth and development. However, to date, our knowledge of how plants sense and transduce the N signals is very limited. To better understand the molecular mechanisms of plant N responses, we took two-dimensional gel-based proteomic and phosphoproteomic approaches to profile the proteins with abundance and phosphorylation state changes during nitrate deprivation and recovery in the model plant Arabidopsis thaliana.
View Article and Find Full Text PDFBackground: Rice is commonly known as a staple crop consumed worldwide, though with several rice proteins being reported for allergic properties in clinical studies. Thus, there is a growing need for the development of an animal model to better understand the allergenicity of rice proteins and the immunological and pathophysiological mechanisms underlying the development of food allergy.
Methods: Groups of BALB/c mice were sensitized daily with freshly homogenized rice flour (30 mg or 80 mg) without adjuvant by intragastric gavage.
We report a large-scale analysis of the patterns of genome-wide genetic variation in soybeans. We re-sequenced a total of 17 wild and 14 cultivated soybean genomes to an average of approximately ×5 depth and >90% coverage using the Illumina Genome Analyzer II platform. We compared the patterns of genetic variation between wild and cultivated soybeans and identified higher allelic diversity in wild soybeans.
View Article and Find Full Text PDFYchF is a subfamily of the Obg family in the TRAFAC class of P-loop GTPases. The wide distribution of YchF homologues in both eukarya and bacteria suggests that they are descendents of an ancient protein, yet their physiological roles remain unclear. Using the OsYchF1-OsGAP1 pair from rice as the prototype, we provide evidence for the regulation of GTPase/ATPase activities and RNA binding capacity of a plant YchF (OsYchF1) by its regulatory protein (OsGAP1).
View Article and Find Full Text PDFReceptor-like protein kinases (RLKs) containing an extracellular leucine-rich repeat (eLRR) domain, a transmembrane domain and a cytoplasmic kinase domain play important roles in plant disease resistance. Simple eLRR domain proteins structurally resembling the extracellular portion of the RLKs may also participate in signalling transduction and plant defence response. Yet the molecular mechanisms and subcellular localization in regulating plant disease resistance of these simple eLRR domain proteins are still largely unclear.
View Article and Find Full Text PDFG-proteins (guanine nucleotide-binding proteins that usually exhibit GTPase activities) and related signal transduction processes play important roles in mediating plant defense responses; here, a rice (Oryza sativa) cDNA clone, OsGAP1, encoding a GTPase-activating protein (GAP) that also contains a protein kinase C conserved region 2 (C2) domain is reported. An interacting G-protein partner for the OsGAP1 protein was identified by yeast two-hybrid library screening and confirmed by co-immunoprecipitation; the GTPase-activation activity of OsGAP1 on this interacting G-protein was demonstrated using in vitro assays. OsGAP1 was induced by wounding in rice and the presence of the R locus Xa14 enhances such induction.
View Article and Find Full Text PDFA cDNA clone (OsRHC1) was obtained, which encodes a novel RING zinc finger protein sharing similar structural features (multiple transmembrane domains at the N-half; a unique RING zinc finger consensus Cys-X(2)-Cys-X(11)-Cys-X-His-X(3)-Cys-X(2)-Cys-X(6)-Cys-X(2)-Cys at the C terminus) to a group of closely related annotated proteins from both monocots and dicots. OsRHC1 was found to be localized on plasma membrane of rice cells and induced by wounding in rice lines containing Xa loci. Ecotopic expression of the OsRHC1 cDNA from rice (a monocot) in transgenic Arabidopsis thaliana (a dicot) enhanced the defence response toward Pseudomonas syringae pv.
View Article and Find Full Text PDFT-cell acute lymphoblastic leukemias (T-ALLs) are highly malignant tumors with 20% of patients continues to fail therapy, in part due to chemoresistance of T-ALL cells via largely unknown mechanisms. Here, we showed that lack of Bcl-2-interacting mediator of cell death (Bim)(EL) protein expression, a BH3-only member of the Bcl-2 family proteins, conferred resistance of a T-ALL cell line, Sup-T1, to etoposide-induced apoptosis. Overexpression of Bim(EL) significantly restored its sensitivity to etoposide-induced caspase activation and poly(ADP-ribose) polymerase cleavage.
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