Abstract The AMMONIUM TRANSPORTER (AMT) family comprises six isoforms in Arabidopsis thaliana. Here, we describe the complete functional organization of root-expressed AMTs for high-affinity ammonium uptake. High-affinity influx 15N-labeled two transposon-tagged amt1;2 lines was reduced by 18 to 26% compared with wild-type plants. Enrichment AMT1;2 protein plasma membrane and localization promoter activity endodermis root cortex indicated that mediates uptake entering via apoplasmic...

Summary Rice ( Oryza sativa L.) plants possess three homologous but distinct genes for cytosolic glutamine synthetase (GS1): these are OsGS1;1 , OsGS1;2 and OsGS1;3 . was expressed in all organs tested with higher expression leaf blades, while were mainly roots spikelets, respectively. We characterized knockout mutants caused by insertion of endogenous retrotransposon Tos17 into the exon‐8 (lines ND8037 ND9801) or exon‐10 (line NC2327) Mendelian segregation occurred each progeny....

Summary In Arabidopsis four root‐expressed AMT genes encode functional ammonium transporters, which raises the question of their role in primary uptake. After pre‐culturing under nitrogen‐deficiency conditions, we quantified influx 15 N‐labeled T‐DNA insertion lines and observed that loss either AMT1;1 or AMT1;3 led to a decrease high‐affinity approximately 30%. Under nitrogen‐sufficient conditions was lower Columbia glabra compared with Wassilewskija (WS), did not contribute significantly...

Glutamine synthetase (GS; EC 6.3.1.2) is a key enzyme of nitrogen assimilation, catalyzing the synthesis glutamine from ammonium and glutamate. In Arabidopsis, cytosolic GS (GS1) was accumulated in roots when plants were excessively supplied with ammonium; however, activity controlled at constant level. The discrepancy between protein content GS1 attributable to kinetic properties expression four distinct isoenzymes encoded by GLN1;1, GLN1;2, GLN1;3 GLN1;4, genes that function complementary...

Rice plants in paddy fields prefer to utilize ammonium as a major nitrogen source. Glutamine synthetase (GS) serves for assimilation of rice root, and ameliorates the toxic effect excess. Among three isoenzymes cytosolic GS1 gene family rice, OsGLN1;1 OsGLN1;2 were abundantly expressed roots. Analysis purified enzymes showed that can be classified into high-affinity subtypes with relatively high Vmax values, compared isoenzyme, GLN1;1, Arabidopsis. Low-affinity forms comparable those...

Abstract Selenium (Se) is an essential element for many organisms but toxic at higher levels. CpNifS a chloroplastic NifS-like protein in Arabidopsis (Arabidopsis thaliana) that can catalyze the conversion of cysteine into alanine and elemental sulfur (S0) selenocysteine Se (Se0). We overexpressed to investigate effects on metabolism plants. overexpression significantly enhanced selenate tolerance (1.9-fold) accumulation (2.2-fold). overexpressors showed reduced incorporation protein, which...

Glutamine synthetase (GS) catalyzes a reaction that incorporates ammonium into glutamate and yields glutamine in the cytosol chloroplasts. Although enzymatic characteristics of GS1 isozymes are well known, their physiological functions assimilation regulation roots remain unclear. In this study we show evidence two cytosolic (GLN1;2 GLN1;3) contribute to Arabidopsis roots. T-DNA insertion lines for GLN1;2 GLN1;3 (i.e. gln1;2 gln1;3 single-mutants), gln1;2:gln1;3 double-mutant, wild-type...

Plant roots under nitrogen deficient conditions with access to both ammonium and nitrate ions, will take up first. This preference for rather than emphasizes the importance of assimilation machinery in roots. Glutamine synthetase (GS) glutamate synthase (GOGAT) catalyze conversion 2-oxoglutarate glutamine glutamate. Higher plants have two GOGAT species, ferredoxin-dependent (Fd-GOGAT) nicotinamide adenine dinucleotide (NADH)-GOGAT. While Fd-GOGAT participates ammonium, which is derived from...

A rice Ca2+-dependent protein kinase, OsCDPK7, is a positive regulator commonly involved in the tolerance to cold and salt/drought. We carried out situ detection of transcript immunolocalization protein. In wild-type plants under both stress conditions, OsCDPK7 was expressed predominantly vascular tissues crowns roots, bundles central cylinder, respectively, where water occurs most severely. This enzyme also peripheral cylinder crown root sclerenchyma. Similar localization patterns with...

Asparagine is synthesized from glutamine by the reaction of asparagine synthetase (AS) and major nitrogen form in both xylem phloem sap rice (Oryza sativa L.). There are two genes encoding AS, OsAS1 OsAS2, rice, but functions individual AS isoenzymes largely unknown. Cell type- NH4+-inducible expression as well analyses knockout mutants were carried out this study to characterize AS1. was mainly expressed roots, with situ hybridization showing that corresponding mRNA specifically accumulated...

Abstract RNAs that code for the major rice storage proteins are localized to specific subdomains of cortical endoplasmic reticulum (ER) in developing endosperm. Prolamine ER and delimit prolamine intracisternal inclusion granules (PB-ER), whereas glutelin targeted cisternal ER. To study transport surface protein bodies living endosperm cells, we adapted a two-gene system consisting green fluorescent (GFP) fused viral RNA binding MS2 hybrid containing tandem sites. Using laser scanning...

The development and elongation of active tillers in rice was severely reduced by a lack cytosolic glutamine synthetase1;2 (GS1;2), and, to lesser extent, NADH-glutamate synthase1 knockout mutants. In situ hybridization using the basal part wild-type seedlings clearly showed that expression OsGS1;2 detected phloem companion cells nodal vascular anastomoses large bundles axillary buds. Accumulation lignin, visualized phloroglucin HCl, also observed these tissues. GS1;2 resulted accumulation...

A mutation abolishing cytosolic glutamine synthetase1;2 (GS1;2) activity impairs assimilation of ammonium into in both roots and basal portions shoots, severely decreases axillary bud outgrowth (tillering) mutant rice seedlings. Although the gs1;2 phenotype is independent strigolactone, which inhibits tillering, it also demonstrates glutamine- or related metabolite-responsive biosynthesis cytokinin (CK), promotes tillering. Here, we examined connection between GS1;2 CK during focusing on...

Improvement in photosynthesis is one of the most promising approaches to increase grain yields. Transgenic rice plants overproducing Rubisco by 30% (RBCS-sense plants) showed up 28% yields under sufficient nitrogen (N) fertilization using an isolated experimental paddy field (Yoon et al. Nat Food 1:134-139, 2020). The plant N contents above-ground sections and flag leaves were higher RBCS-sense than wild-type during ripening period, which may be reasons for increased However, some imprecise...

Ammonium is combined with glutamate to form glutamine. This reaction catalyzed by glutamine synthetase (GS or GLN). Plants harbor several isoforms of cytosolic GS (GS1). Rice GS1;3 highly expressed in seeds during grain filling and germination, suggesting a unique role these processes. study aimed investigate the for rice growth yield. Tos17 insertion lines were isolated, nitrogen (N), amino acid, ammonium contents mutant grains compared wild-type grains. The spatiotemporal expression yield...

Rice (Oryza sativa) is one of the most important food crops in world. Numerous quantitative trait loci or genes controlling panicle architecture have been identified to increase grain yield. Yet yield, defined as product number well-ripened grains and their weight, a complex that determined by multiple factors such source, sink translocation capacity. Mechanistic modelling capturing capacities transport will help theoretical design crop ideotypes guarantee high Here we present mathematical...

Abstract Chloroplast glyceraldehyde-3-phosphate dehydrogenase (GAPDH) limits the regeneration of ribulose 1,5-bisphosphate (RuBP) in Calvin–Benson cycle. However, it does not always limit rate CO2 assimilation. In present study, effects overproduction GAPDH on assimilation under elevated [CO2] conditions, where capacity for RuBP photosynthesis, were examined transgenic rice (Oryza sativa). activity was increased to 3.2- and 4.5-fold wild-type levels by co-overexpression genes, GAPA GAPB,...

Abstract To increase the yield potential while limiting environmental impact of N management practices is an important issue in rice cultivation. The large-grain cultivar Akita 63 showed higher N-use efficiency for grain production. elucidate this, we analyzed characteristics comparison with those a maternal cultivar, Oochikara large grain, paternal 39 normal and Japanese leading Akitakomachi. yields were 20% than 39, 50% Akitakomachi same application. superior uptake capacity. Whereas...

C4 plants can fix CO2 efficiently using -concentrating mechanisms (CCMs), but they require additional ATP. To supply the ATP, operate at higher rates of cyclic electron transport around photosystem I (PSI), in which electrons are transferred from ferredoxin to plastoquinone. Recently, it has been reported that NAD(P)H dehydrogenase-like complex (NDH) accumulated thylakoid membrane leaves plants, making a candidate for synthesis ATP used CCM. In addition, have levels PROTON GRADIENT...

Asparagine is one of the most dominant organic nitrogen compounds in phloem and xylem sap a wide range plant species. Asparaginase (ASNase; EC, 3.5.1.1) catabolizes asparagine into aspartate ammonium; therefore, it suggested to play key role metabolism within legume sink organs. However, metabolic fate source organs during rice seed production remains be elucidated. Therefore, main objective this study investigate temporal spatial manner production. For purpose, expression genes involved...

Our previous transcriptomic analysis revealed that downregulation of nitrogen and carbon metabolism in the basal portions shoots inhibited cytosolic glutamine synthetase1;2 (GS1;2), which severely reduced rice tiller number. In present study, we used mutants lacking GS1;2 (gs1;2 mutants) to determine contribution growth. Metabolomic indicated effects disorder such as reductions levels sugar metabolites (e.g., sucrose glucose 6-phosphate) shoot gs1;2 mutant seedlings. Decrease caused by lack...

Abstract The availability of inorganic phosphate (Pi) for ATP synthesis is thought to limit photosynthesis at elevated [CO2] when Pi regeneration via sucrose or starch limited. We report here another mechanism the occurrence Pi-limited caused by insufficient capacity chloroplast triose isomerase (cpTPI). In cpTPI-antisense transgenic rice (Oryza sativa) plants with 55%–86% reductions in cpTPI content, CO2 sensitivity rate assimilation (A) decreased and even reversed [CO2]. pool sizes...