Cytosolic phosphofructokinases are important for sugar homeostasis in leaves of Arabidopsis thaliana

2021 ◽  
Author(s):  
Laura Kathrine Perby ◽  
Simon Richter ◽  
Konrad Weber ◽  
Alina Johanna Hieber ◽  
Natalia Hess ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Double Mutant ◽  
Normal Growth ◽  
Growth Conditions ◽  
Metabolic Phenotype ◽  
Minor Role ◽  
Knock Out ◽  
Genes Encoding ◽  
Fructose 1,6 Bisphosphate ◽  
Sugar Homeostasis

Abstract Background and Aims ATP-dependent phosphofructokinases (PFKs) catalyse phosphorylation of the carbon-1 position of fructose-6-phosphate, to form fructose-1,6-bisphosphate. In the cytosol, this is considered a key step in channelling carbon into glycolysis. Arabidopsis thaliana has seven genes encoding PFK isoforms, two chloroplastic and five cytosolic. This study focusses on the four major cytosolic isoforms of PFK in vegetative tissues of A. thaliana. Methods We have isolated homozygous knock-out individual mutants (pfk1, pfk3, pfk6, pfk7) and two double mutants (pfk1/7 and pfk3/6) and characterized their growth and metabolic phenotypes. Key Results In contrast to single mutants and the double mutant pfk3/6 for the hypoxia-responsive isoforms, the double mutant pfk1/7 had reduced PFK activity and shows a clear visual and metabolic phenotype with reduced shoot growth, early flowering, and elevated hexose levels. This mutant also has an altered ratio of short/long aliphatic glucosinolates and an altered root-shoot distribution. Surprisingly, this mutant does not show any major changes in short-term carbon flux and in levels of hexose-phosphates. Conclusions We conclude that the two isoforms PFK1 and PFK7 are important for sugar homeostasis in leaf metabolism and apparently source/sink relations in Arabidopsis, while PFK3 and PFK6 only play a minor role under normal growth conditions.

scholarly journals Overexpression of WAX INDUCER1/SHINE1 Gene Enhances Wax Accumulation under Osmotic Stress and Oil Synthesis in Brassica napus

2019 ◽  
Vol 20 (18) ◽  
pp. 4435 ◽  
Author(s):  
Ning Liu ◽  
Jie Chen ◽  
Tiehu Wang ◽  
Qing Li ◽  
Pengpeng Cui ◽  
...  
Keyword(s):  
Salt Stress ◽  
Brassica Napus ◽  
De Novo ◽  
Normal Growth ◽  
Acid Synthesis ◽  
Growth Conditions ◽  
Lipid Profiling ◽  
Intracellular Lipids ◽  
Oil Synthesis ◽  
Genes Encoding

WAX INDUCER1/SHINE1 (WIN1) belongs to the AP2/EREBP transcription factor family and plays an important role in wax and cutin accumulation in plants. Here we show that BnWIN1 from Brassica napus (Bn) has dual functions in wax accumulation and oil synthesis. Overexpression (OE) of BnWIN1 led to enhanced wax accumulation and promoted growth without adverse effects on oil synthesis under salt stress conditions. Lipid profiling revealed that BnWIN1-OE plants accumulated more waxes with elevated C29-alkanes, C31-alkanes, C28-alcohol, and C29-alcohol relative to wild type (WT) under salt stress. Moreover, overexpression of BnWIN1 also increased seed oil content under normal growth conditions. BnWIN1 directly bound to the promoter region of genes encoding biotin carboxyl carrier protein 1 (BCCP1), glycerol-3-phosphate acyltransferase 9 (GPAT9), lysophosphatidic acid acyltransferase 5 (LPAT5), and diacylglycerol acyltransferase 2 (DGAT2) involved in the lipid anabolic process. Overexpression of BnWIN1 resulted in upregulated expression of numerous genes involved in de novo fatty acid synthesis, wax accumulation, and oil production. The results suggest that BnWIN1 is a transcriptional activator to regulate the biosynthesis of both extracellular and intracellular lipids.

scholarly journals Evolutionary History and Activity of RNase H1-Like Proteins in Arabidopsis thaliana

2020 ◽  
Vol 61 (6) ◽  
pp. 1107-1119
Author(s):  
Jan Kuciński ◽  
Sebastian Chamera ◽  
Aleksandra Kmera ◽  
M Jordan Rowley ◽  
Sho Fujii ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Embryonic Development ◽  
Evolutionary History ◽  
Common Ancestor ◽  
Normal Growth ◽  
Plastid Dna ◽  
Growth Conditions ◽  
Replicative Stress ◽  
The Common ◽  
Rna:Dna Hybrids

Abstract RNase H1 is an endonuclease specific toward the RNA strand of RNA:DNA hybrids. Members of this protein family are present in most living organisms and are essential for removing RNA that base pairs with DNA. It prevents detrimental effects of RNA:DNA hybrids and is involved in several biological processes. Arabidopsis thaliana has been previously shown to contain three genes encoding RNase H1 proteins that localize to three distinct cellular compartments. We show that these genes originate from two gene duplication events. One occurred in the common ancestor of dicots and produced nuclear and organellar RNase H1 paralogs. Second duplication occurred in the common ancestor of Brassicaceae and produced mitochondrial- and plastid-localized proteins. These proteins have the canonical RNase H1 activity, which requires at least four ribonucleotides for endonucleolytic digestion. Analysis of mutants in the RNase H1 genes revealed that the nuclear RNH1A and mitochondrial RNH1B are dispensable for development under normal growth conditions. However, the presence of at least one organellar RNase H1 (RNH1B or RNH1C) is required for embryonic development. The plastid-localized RNH1C affects plastid DNA copy number and sensitivity to replicative stress. Our results present the evolutionary history of RNH1 proteins in A. thaliana, demonstrate their canonical RNase H1 activity and indicate their role in early embryonic development.

scholarly journals Use of Inducible Feedback-ResistantN-Acetylglutamate Synthetase (argA) Genes for Enhanced Arginine Biosynthesis by Genetically EngineeredEscherichia coli K-12 Strains

1998 ◽  
Vol 64 (5) ◽  
pp. 1805-1811 ◽  
Author(s):  
B. S. Rajagopal ◽  
Joseph DePonte ◽  
Mendel Tuchman ◽  
Michael H. Malamy
Keyword(s):  
Feedback Inhibition ◽  
Expression System ◽  
Point Mutations ◽  
Normal Growth ◽  
Growth Conditions ◽  
Wild Type ◽  
Arginine Biosynthesis ◽  
E Coli ◽  
Genes Encoding ◽  
K 12

ABSTRACT The goal of this work was to construct Escherichia colistrains capable of enhanced arginine production. The arginine biosynthetic capacity of previously engineered E. colistrains with a derepressed arginine regulon was limited by the availability of endogenous ornithine (M. Tuchman, B. S. Rajagopal, M. T. McCann, and M. H. Malamy, Appl. Environ. Microbiol. 63:33–38, 1997). Ornithine biosynthesis is limited due to feedback inhibition by arginine of N-acetylglutamate synthetase (NAGS), the product of the argA gene and the first enzyme in the pathway of arginine biosynthesis in E. coli. To circumvent this inhibition, the argA genes from E. coli mutants with feedback-resistant (fbr) NAGS were cloned into plasmids that contain “arg boxes,” which titrate the ArgR repressor protein, with or without the E. coli carABgenes encoding carbamyl phosphate synthetase and the argIgene for ornithine transcarbamylase. The free arginine production rates of “arg-derepressed” E. coli cells overexpressing plasmid-encoded carAB, argI, and fbr argA genes were 3- to 15-fold higher than that of an equivalent system overexpressing feedback-sensitive wild-type (wt)argA. The expression system with fbr argAproduced 7- to 35-fold more arginine than a system overexpressingcarAB and argI genes on a plasmid in a strain with a wt argA gene on the chromosome. The arginine biosynthetic capacity of arg-derepressed DH5α strains with plasmids containing only the fbr argA gene was similar to that of cells with plasmids also containing the carABand argI genes. Plasmids containing wt or fbrargA were stably maintained under normal growth conditions for at least 18 generations. DNA sequencing identified different point mutations in each of the fbr argA mutants, specifically H15Y, Y19C, S54N, R58H, G287S, and Q432R.

scholarly journals Colocation of Genes Encoding a tRNA-mRNA Hybrid and a Putative Signaling Peptide on Complementary Strands in the Genome of the Hyperthermophilic Bacterium Thermotoga maritima

2006 ◽  
Vol 188 (19) ◽  
pp. 6802-6807 ◽  
Author(s):  
Clemente I. Montero ◽  
Derrick L. Lewis ◽  
Matthew R. Johnson ◽  
Shannon B. Conners ◽  
Elizabeth A. Nance ◽  
...  
Keyword(s):  
Thermotoga Maritima ◽  
Normal Growth ◽  
Growth Conditions ◽  
Open Reading Frames ◽  
Transcriptional Responses ◽  
Gene Encoding ◽  
Hyperthermophilic Bacterium ◽  
Genes Encoding ◽  
Original Genome ◽  
Opposite Strand

ABSTRACT In the genome of the hyperthermophilic bacterium Thermotoga maritima, TM0504 encodes a putative signaling peptide implicated in population density-dependent exopolysaccharide formation. Although not noted in the original genome annotation, TM0504 was found to colocate, on the opposite strand, with the gene encoding ssrA, a hybrid of tRNA and mRNA (tmRNA), which is involved in a trans-translation process related to ribosome rescue and is ubiquitous in bacteria. Specific DNA probes were designed and used in real-time PCR assays to follow the separate transcriptional responses of the colocated open reading frames (ORFs) during transition from exponential to stationary phase, chloramphenicol challenge, and syntrophic coculture with Methanococcus jannaschii. TM0504 transcription did not vary under normal growth conditions. Transcription of the tmRNA gene, however, was significantly up-regulated during chloramphenicol challenge and in T. maritima bound in exopolysaccharide aggregates during methanogenic coculture. The significance of the colocation of ORFs encoding a putative signaling peptide and tmRNA in T. maritima is intriguing, since this overlapping arrangement (tmRNA associated with putative small ORFs) was found to be conserved in at least 181 bacterial genomes sequenced to date. Whether peptides related to TM0504 in other bacteria play a role in quorum sensing is not yet known, but their ubiquitous colocalization with respect to tmRNA merits further examination.

scholarly journals Strong morphological defects in conditional Arabidopsis abp1 knock-down mutants generated in absence of functional ABP1 protein

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 86 ◽  
Author(s):  
Jaroslav Michalko ◽  
Matouš Glanc ◽  
Catherine Perrot-Rechenmann ◽  
Jiří Friml
Keyword(s):  
Biological Function ◽  
Normal Growth ◽  
Growth Conditions ◽  
Auxin Signaling ◽  
Loss Of Function ◽  
Knock Out ◽  
Knock Down ◽  
Morphological Defects ◽  
Auxin Binding Protein ◽  
Target Effects

The Auxin Binding Protein 1 (ABP1) is one of the most studied proteins in plants. Since decades ago, it has been the prime receptor candidate for the plant hormone auxin with a plethora of described functions in auxin signaling and development. The developmental importance of ABP1 has recently been questioned by identification of Arabidopsis thaliana abp1 knock-out alleles that show no obvious phenotypes under normal growth conditions. In this study, we examined the contradiction between the normal growth and development of the abp1 knock-outs and the strong morphological defects observed in three different ethanol-inducible abp1 knock-down mutants (abp1-AS, SS12K, SS12S). By analyzing segregating populations of abp1 knock-out vs. abp1 knock-down crosses we show that the strong morphological defects that were believed to be the result of conditional down-regulation of ABP1 can be reproduced also in the absence of the functional ABP1 protein. This data suggests that the phenotypes in abp1 knock-down lines are due to the off-target effects and asks for further reflections on the biological function of ABP1 or alternative explanations for the missing phenotypic defects in the abp1 loss-of-function alleles.

scholarly journals Coordination and assembly of protein complexes encoded across mitochondrial and nuclear genomes is assisted by CLPP2 in Arabidopsis thaliana

2020 ◽  
Author(s):  
Jakob Petereit ◽  
Owen Duncan ◽  
Monika W Murcha ◽  
Ricarda Fenske ◽  
Emilia Cincu ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Protein Degradation ◽  
Protein Import ◽  
Protein Complexes ◽  
Single Gene ◽  
Mitochondrial Protein ◽  
Protein Homeostasis ◽  
Knock Out ◽  
Genes Encoding ◽  
Nuclear Genomes

AbstractProtein homeostasis in eukaryotic organelles and their progenitor prokaryotes is regulated by a series of proteases including the caseinolytic protease (CLPP). CLPP has essential roles in chloroplast biogenesis and maintenance, but the significance of the plant mitochondrial CLPP remains unknown and factors that aid coordination of nuclear and mitochondrial encoded subunits for complex assembly in mitochondria await discovery. We generated knock-out lines of the single gene for the mitochondrial CLP protease subunit, CLPP2, in Arabidopsis thaliana. Mutants had higher abundance of transcripts from mitochondrial genes encoding OXPHOS protein complexes, while transcripts for nuclear genes encoding other subunits of the same complexes showed no change in abundance. In contrast, the protein abundance of specific nuclear-encoded subunits in OXPHOS complexes I and V increased in CLPP2 knockouts, without accumulation of mitochondrial-encoded counterparts in the same complex. Protein complexes mainly or entirely encoded in the nucleus were unaffected. Analysis of protein import, assembly and function of Complex I revealed that while function was retained, protein homeostasis was disrupted through decreased assembly, leading to accumulation of soluble subcomplexes of nuclear-encoded subunits. Therefore, CLPP2 contributes to the mitochondrial protein degradation network through supporting coordination and assembly of protein complexes encoded across mitochondrial and nuclear genomes.One sentence summaryCLPP contributes to the mitochondrial protein degradation network through supporting coordination and assembly of protein complexes encoded across mitochondrial and nuclear genomes.

scholarly journals Direct comparison of Arabidopsis gene expression reveals different responses to melatonin versus auxin

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Sajal F. Zia ◽  
Oliver Berkowitz ◽  
Frank Bedon ◽  
James Whelan ◽  
Ashley E. Franks ◽  
...  
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Biotic Stress ◽  
Plant Protection ◽  
Normal Growth ◽  
Direct Repeat ◽  
Growth Conditions ◽  
Differentially Expressed ◽  
Naphthalene Acetic Acid ◽  
Regulatory Pathways

Abstract Background Melatonin (N-acetyl-5-methoxytryptamine) in plants, regulates shoot and root growth and alleviates environmental stresses. Melatonin and the phyto-hormone auxin are tryptophan-derived compounds. However, it largely remains controversial as to whether melatonin and auxin act through similar or overlapping signalling and regulatory pathways. Results Here, we have used a promoter-activation study to demonstrate that, unlike auxin (1-naphthalene acetic acid, NAA), melatonin neither induces Direct repeat 5 DR5 expression in Arabidopsis thaliana roots under normal growth conditions nor suppresses the induction of Alternative oxidase 1a AOX1a in leaves upon Antimycin A treatment, both of which are the hallmarks of auxin action. Additionally, comparative global transcriptome analysis conducted on Arabidopsis treated with melatonin or NAA revealed differences in the number and types of differentially expressed genes. Auxin (4.5 μM) altered the expression of a diverse and large number of genes whereas melatonin at 5 μM had no significant effect but melatonin at 100 μM had a modest effect on transcriptome compared to solvent-treated control. Interestingly, the prominent category of genes differentially expressed upon exposure to melatonin trended towards biotic stress defence pathways while downregulation of key genes related to photosynthesis was observed. Conclusion Together these findings indicate that though they are both indolic compounds, melatonin and auxin act through different pathways to alter gene expression in Arabidopsis thaliana. Furthermore, it appears that effects of melatonin enable Arabidopsis thaliana to prioritize biotic stress defence signalling rather than growth. These findings clear the current confusion in the literature regarding the relationship of melatonin and auxin and also have greater implications of utilizing melatonin for improved plant protection.

scholarly journals The Arabidopsis thaliana E3 Ubiquitin Ligase BRIZ Functions in Abscisic Acid Response

2021 ◽  
Vol 12 ◽  
Author(s):  
Katrina J. Linden ◽  
Mon Mandy Hsia ◽  
Yi-Tze Chen ◽  
Judy Callis
Keyword(s):  
Arabidopsis Thaliana ◽  
Abscisic Acid ◽  
E3 Ligase ◽  
Normal Growth ◽  
Growth Conditions ◽  
Aba Signaling ◽  
Wild Type ◽  
Ubiquitin System ◽  
Early Seedling ◽  
Cotyledon Expansion

The ubiquitin system is essential for multiple hormone signaling pathways in plants. Here, we show that the Arabidopsis thaliana E3 ligase BRIZ, a heteromeric ligase that consists minimally of BRIZ1 and BRIZ2 proteins, functions in abscisic acid (ABA) signaling or response. briz1 and briz2 homozygous mutants either fail to germinate or emerge later than wild-type seedlings, with little cotyledon expansion or root elongation and no visible greening. Viability staining indicates that briz1 and briz2 embryos are alive but growth-arrested. Germination of briz mutants is improved by addition of the carotenoid biosynthetic inhibitor fluridone or gibberellic acid (GA3), and briz mutants have improved development in backgrounds deficient in ABA synthesis (gin1-3/aba2) or signaling (abi5-7). Endogenous ABA is not higher in briz2 seeds compared to wild-type seeds, and exogenous ABA does not affect BRIZ mRNAs in imbibed seeds. These results indicate that briz embryos are hypersensitive to ABA and that under normal growth conditions, BRIZ acts to suppress ABA signaling or response. ABA signaling and sugar signaling are linked, and we found that briz1 and briz2 mutants excised from seed coats are hypersensitive to sucrose. Although briz single mutants do not grow to maturity, we were able to generate mature briz2-3 abi5-7 double mutant plants that produced seeds. These seeds are more sensitive to exogenous sugar and are larger than seeds from sibling abi5-7 BRIZ2/briz2-3 plants, suggesting that BRIZ has a parental effect on seed development. From these data, we propose a model in which the BRIZ E3 ligase suppresses ABA responses during seed maturation and germination and early seedling establishment.

scholarly journals Pressure-Induced Endocytic Degradation of the Saccharomyces cerevisiae Low-Affinity Tryptophan Permease Tat1 Is Mediated by Rsp5 Ubiquitin Ligase and Functionally Redundant PPxY Motif Proteins

2013 ◽  
Vol 12 (7) ◽  
pp. 990-997 ◽  
Author(s):  
Asaha Suzuki ◽  
Takahiro Mochizuki ◽  
Satoshi Uemura ◽  
Toshiki Hiraki ◽  
Fumiyoshi Abe
Keyword(s):  
Saccharomyces Cerevisiae ◽  
High Pressure ◽  
Hydrostatic Pressure ◽  
Ubiquitin Ligase ◽  
High Hydrostatic Pressure ◽  
Intracellular Localization ◽  
Normal Growth ◽  
Growth Conditions ◽  
Content Type ◽  
Genes Encoding

ABSTRACT Cells of Saccharomyces cerevisiae express two tryptophan permeases, Tat1 and Tat2, which have different characteristics in terms of their affinity for tryptophan and intracellular localization. Although the high-affinity permease Tat2 has been well documented in terms of its ubiquitin-dependent degradation, the low-affinity permease Tat1 has not yet been characterized fully. Here we show that a high hydrostatic pressure of 25 MPa triggers a degradation of Tat1 which depends on Rsp5 ubiquitin ligase and the EH domain-containing protein End3. Tat1 was resistant to a 3-h cycloheximide treatment, suggesting that it is highly stable under normal growth conditions. The ubiquitination of Tat1 most likely occurs at N-terminal lysines 29 and 31. Simultaneous substitution of arginine for the two lysines prevented Tat1 degradation, but substitution of either of them alone did not, indicating that the roles of lysines 29 and 31 are redundant. When cells were exposed to high pressure, Tat1-GFP was completely lost from the plasma membrane, while substantial amounts of Tat1 K29R-K31R -GFP remained. The HPG1-1 (Rsp5 P514T ) and rsp5-ww3 mutations stabilized Tat1 under high pressure, but any one of the rsp5-ww1 , rsp5-ww2 , and bul1 Δ bul2 Δ mutations or single deletions of genes encoding arrestin-related trafficking adaptors did not. However, simultaneous loss of 9-arrestins and Bul1/Bul2 prevented Tat1 degradation at 25 MPa. The results suggest that multiple PPxY motif proteins share some essential roles in regulating Tat1 ubiquitination in response to high hydrostatic pressure.

scholarly journals The Application of a Commercially Available Citrus-Based Extract Mitigates Moderate NaCl-Stress in Arabidopsis thaliana Plants

Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1010
Author(s):  
Johannes Loubser ◽  
Paul Hills
Keyword(s):  
Arabidopsis Thaliana ◽  
Salt Stress ◽  
Chlorophyll Content ◽  
Normal Growth ◽  
Growth Conditions ◽  
Nacl Stress ◽  
Preliminary Evidence ◽  
Stomatal Conductivity ◽  
Expression Of Genes

Aims: The aim of this study was to assess the effect of BC204 as a plant biostimulant on Arabidopsis thaliana plants under normal and NaCl-stressed conditions. Methods: For this study, ex vitro and in vitro growth experiments were conducted to assess the effect of both NaCl and BC204 on basic physiological parameters such as biomass, chlorophyll, proline, malondialdehyde, stomatal conductivity, Fv/Fm and the expression of four NaCl-responsive genes. Results: This study provides preliminary evidence that BC204 mitigates salt stress in Arabidopsis thaliana. BC204 treatment increased chlorophyll content, fresh and dry weights, whilst reducing proline, anthocyanin and malondialdehyde content in the presence of 10 dS·m−1 electroconductivity (EC) salt stress. Stomatal conductivity was also reduced by BC204 and NaCl in source leaves. In addition, BC204 had a significant effect on the expression of salinity-related genes, stimulating the expression of salinity-related genes RD29A and SOS1 independently of NaCl-stress. Conclusions: BC204 stimulated plant growth under normal growth conditions by increasing above-ground shoot tissue and root and shoot growth in vitro. BC204 also increased chlorophyll content while reducing stomatal conductivity. BC204 furthermore mitigated moderate to severe salt stress (10–20 dS·m−1) in A. thaliana. Under salt stress conditions, BC204 reduced the levels of proline, anthocyanin and malondialdehyde. The exact mechanism by which this occurs is unknown, but the results in this study suggest that BC204 may act as a priming agent, stimulating the expression of genes such as SOS1 and RD29A.

Sign in / Sign up

Export Citation Format

Share Document