Summary In plants, the amino acid asparagine serves as an important nitrogen transport compound whose levels are dramatically regulated by light in many plant species, including Arabidopsis thaliana . To elucidate mechanisms regulating flux of assimilated into asparagine, we examined regulation gene family for synthetase Arabidopsis. addition to previously identified ASN1 gene, a novel class genes ( ASN2 and ASN3 ) functional complementation yeast auxotroph. The proteins encoded ASN2/3 cDNAs...

Abstract Plant isoprenoids are synthesized via two independent pathways, the cytosolic mevalonate (MVA) pathway and plastid nonmevalonate pathway. The Escherichia coli IspH (LytB) protein is involved in last step of We have isolated an Arabidopsis (Arabidopsis thaliana) ispH null mutant that has albino phenotype generated transgenic lines showing various patterns caused by transgene-induced gene silencing. initiation phenotypes rendered silencing can arise independently from multiple sites...

Glutamine is a major amino donor for the synthesis of acids, nucleotides, and other nitrogen-containing compounds in all organisms. In addition to its role nutrition metabolism, glutamine can also function as signaling molecule bacteria, yeast, humans. By contrast, functions remain unclear plants. We demonstrated that could effectively support growth rice seedlings. glutamine-treated roots, contents increased dramatically, whereas levels glutamate remained relatively constant. Transcriptome...

Nitrogen (N) deficiency is one of the most common problems in rice. The symptoms N are well documented, but underlying molecular mechanisms largely unknown Here, we studied early events associated with starvation (-N, 1 h), focusing on amino acid analysis and identification -N-regulated genes rice roots. Interestingly, levels glutamine rapidly decreased within 15 min -N treatment, indicating that part N-deficient signals could be mediated by glutamine. Transcriptome revealed involved...

Glutamate is an active amino acid. In addition to protein synthesis and metabolism, increasing evidence indicates that glutamate may also function as a signaling molecule in plants. Still, little known about the nutritional role of genes are directly regulated by rice. Exogenous could serve nitrogen nutrient support growth rice seedlings, but it was not effective ammonium nitrate or glutamine. nitrogen-starved most abundant free acid feeding rapidly significantly increased endogenous levels...

Glutamine (Gln) is the first amino acid synthesized in nitrogen (N) assimilation plants. Gln synthetase (GS), converting glutamate (Glu) and NH4+ into at expense of ATP, one oldest enzymes all life domains. Plants have multiple GS isoenzymes that work individually or cooperatively to ensure supply sufficient for plant growth development under various conditions. a building block protein synthesis an N-donor biosynthesis acids, nucleic sugars vitamin B coenzymes. Most reactions using as are...

Abstract The production of glutamine (Gln) from NO3− and NH4+ requires ATP, reducing power, carbon skeletons. Plants may redirect these resources to other physiological processes using Gln directly. However, feeding as the sole nitrogen (N) source has complex effects on plants. Under optimal concentrations, Arabidopsis (Arabidopsis thaliana) seedlings grown have similar primary root lengths, more lateral roots, smaller leaves, higher amounts amino acids proteins compared those NH4NO3. While...

In Arabidopsis, RNA editing changes more than 500 cytidines to uridines in mitochondrial transcripts. The enzyme and co-factors involved these processes are largely unknown. We have identified a nuclear gene SLOW GROWTH1 (SLO1) encoding an E motif-containing pentatricopeptide repeat protein that is required for of nad4 nad9 Arabidopsis mitochondria. SLO1 localized the mitochondrion, its absence gives rise small plants with slow growth delayed development. A survey approximately sites reveals...

Mitochondria play a pivotal role in most eukaryotic cells, as they are responsible for the generation of energy and diverse metabolic intermediates many cellular events. During endosymbiosis, approximately 99% genes encoded by mitochondrial genome were transferred into host nucleus, mitochondria import more than 1000 nuclear-encoded proteins from cytosol to maintain structural integrity fundamental functions, including DNA replication, mRNA transcription RNA metabolism dozens genes. In...

Mitochondria play an important role in maintaining metabolic and energy homeostasis the cell. In plants, impairment mitochondrial functions usually has detrimental effects on growth development. To study genes that are for plant growth, we have isolated a collection of slow (slo) mutants Arabidopsis (Arabidopsis thaliana). One slo mutants, slo3, significant reduction complex I activity. The slo3 mutant four-nucleotide deletion At3g61360 encodes pentatricopeptide repeat (PPR) protein. SLO3...

Summary The physiological role of the NADH‐dependent glutamine‐2‐oxoglutarate aminotransferase (NADH‐GOGAT) enzyme was addressed in Arabidopsis using gene expression analysis and by characterization a knock‐out T‐DNA insertion mutant ( glt1‐T ) single NADH‐GOGAT GLT1 gene. mRNA is expressed at higher levels roots than leaves. This pattern contrasts with GLU1, major encoding Fd‐GOGAT, which most highly leaves involved photorespiration. These distinct organ‐specific patterns suggested...

Starch synthesis and degradation require the participation of many enzymes, occur in both photosynthetic nonphotosynthetic tissues, are subject to environmental developmental regulation. We examine distribution starch vegetative tissues Arabidopsis (Arabidopsis thaliana) expression genes encoding core enzymes for synthesis. is accumulated plastids epidermal, mesophyll, vascular, root cap cells but not proper cells. also identify that can synthesize heterotrophically albino mutants. leaves...

Ammonium has long been used as the predominant form of nitrogen source for paddy rice (Oryza sativa). Recently, increasing evidence suggests that nitrate also plays an important role acquisition in rhizosphere waterlogged rice. and have a synergistic effect on promoting growth. However, molecular responses induced by simultaneous treatment with ammonium less studied Here, we performed transcriptome analysis to identify genes are rapidly regulated (1.43 mM, 30 min) roots. The combination...

Anthocyanin accumulation is a hallmark response to nitrogen (N) deficiency in Arabidopsis. Although the regulation of anthocyanin biosynthesis has been extensively studied, roles chromatin modification this process are largely unknown. In study we show that induced by N modulated HISTONE DEACETYLASE15 (HDA15) Arabidopsis seedlings. The hda15-1 T-DNA insertion mutant accumulated more anthocyanins than wild-type when supply was limited, and caused up-regulation biosynthetic regulatory genes...

The mitochondrion is an important power generator in most eukaryotic cells. To preserve its function, many essential nuclear-encoded factors play specific roles mitochondrial RNA metabolic processes, including editing. editing consists of post-transcriptional deamination, which alters nucleotides transcripts to mediate gene expression. In plant cells, pentatricopeptide repeat proteins (PPRs) participate diverse organellar but only PLS-type PPRs are involved Here, we report a P-type PPR...

Abstract In bacteria, the regulatory ACT domains serve as amino acid-binding sites in some feedback-regulated acid metabolic enzymes. We have identified a novel type of domain-containing protein family Arabidopsis whose members contain domain repeats (the “ACR” family). There are at least eight ACR genes located on each five chromosomes genome. Gene structure comparisons indicate that gene may arisen by duplications. Northern-blot analysis indicates member has distinct expression pattern...

Abstract Background The ACT domain, named after bacterial aspartate kinase, chorismate mutase and TyrA (prephenate dehydrogenase), is a regulatory domain that serves as an amino acid-binding site in feedback-regulated acid metabolic enzymes. We have previously identified novel type of domain-containing protein family, the AC T r epeat (ACR) Arabidopsis . Members ACR ACR1 to ACR8, contain four copies extend throughout entire polypeptide. Here, we describe identification proteins, namely ACR9...

Thiamin diphosphate (TPP, vitamin B1 ) is an essential coenzyme present in all organisms. Animals obtain TPP from their diets, but plants synthesize TPPde novo. We isolated and characterized Arabidopsis pale green1 (pale1) mutant that contained higher concentrations of thiamin monophosphate (TMP) less than the wild type. Supplementation with thiamin, not thiazole pyrimidine precursors, rescued phenotype, indicating pale1 a thiamin-deficient mutant. Map-based cloning whole-genome sequencing...

Abstract The ACT domain ( a spartate kinase, c horismate mutase and T yrA), an allosteric effector binding domain, is commonly found in amino acid metabolic enzymes. In addition to domain-containing enzymes, plants have novel family of AC r epeat (ACR) proteins, which do not contain any recognizable catalytic domain. Arabidopsis has 12 ACR whose functions are largely unknown. To study the ACR11, we characterized two independent T-DNA insertion mutants, acr11-2 acr11-3 . RNA gel-blot analysis...