Abstract Gene transcripts with invariant abundance during development and in the face of environmental stimuli are essential reference points for accurate gene expression analyses, such as RNA gel-blot analysis or quantitative reverse transcription-polymerase chain reaction (PCR). An exceptionally large set data from Affymetrix ATH1 whole-genome GeneChip studies provided means to identify a new generation genes very stable levels model plant species Arabidopsis (Arabidopsis thaliana)....

Abstract Inorganic phosphate (Pi)-signaling pathways in plants are still largely unknown. The Arabidopsis (Arabidopsis thaliana) pho2 mutant overaccumulates Pi leaves Pi-replete conditions. Micrografting revealed that a root genotype is sufficient to yield leaf accumulation. In mutants, does not repress set of starvation-induced genes, including AtIPS1, AT4, and transporters Pht1;8 Pht1;9. Map-based cloning identified PHO2 as At2g33770, an unusual E2 conjugase gene. It was recently shown...

The presence of microRNA species in plant phloem sap suggests potential signaling roles by long-distance regulation gene expression. Proof for such a role phloem-mobile is lacking. Here we show that phosphate (Pi) starvation-induced microRNA399 (miR399) present the two diverse species, rapeseed and pumpkin, levels are strongly specifically increased during Pi deprivation. By performing micro-grafting experiments using Arabidopsis, further chimeric plants constitutively over-expressing miR399...

Abstract The diurnal cycle strongly influences many plant metabolic and physiological processes. Arabidopsis thaliana rosettes were harvested six times during 12-h-light/12-h-dark treatments to investigate changes in gene expression using ATH1 arrays. Diagnostic sets identified from published or in-house profiles of the response light, sugar, nitrogen, water deficit seedlings 4 h darkness illumination at ambient compensation point [CO2]. Many sugar-responsive genes showed large changes,...

Summary To overcome the detection limits inherent to DNA array-based methods of transcriptome analysis, we developed a real-time reverse transcription (RT)-PCR-based resource for quantitative measurement transcripts 1465 Arabidopsis factors (TFs). Using closely spaced gene-specific primer pairs and SYBR Green monitor amplification double-stranded (dsDNA), transcript levels 83% all target genes could be measured in roots or shoots young wild-type plants. Only 4% reactions produced...

Nia30(145) transformants with very low nitrate reductase activity provide an in vivo screen to identify processes that are regulated by nitrate. resembles nitrate-limited wild-type plants respect growth rate and protein amino acid content but accumulates large amounts of when it is grown on high The transcripts for (NR), nitrite reductase, cytosolic glutamine synthetase, glutamate synthase increased; NR increased leaves roots; synthetase roots. phosphoenolpyruvate carboxylase, pyruvate...

Abstract Nitrogen (N) and nitrate (NO3 −) per se regulate many aspects of plant metabolism, growth, development. N/NO3 − also suppresses parts secondary including anthocyanin synthesis. Molecular components for this repression are unknown. We report that three −-induced members the LATERAL ORGAN BOUNDARY DOMAIN (LBD) gene family transcription factors (LBD37, LBD38, LBD39) act as negative regulators biosynthesis in Arabidopsis thaliana. Overexpression each genes absence strongly key synthesis...

Tre6P (trehalose 6-phosphate) is implicated in sugar-signalling pathways plants, but its exact functions vivo are uncertain. One of the main obstacles to discovering these difficulty measuring amount plant tissues. We have developed a highly specific assay, using liquid chromatography coupled MS-Q3 (triple quadrupole MS), measure femto-picomole range. The content sucrose-starved Arabidopsis thaliana seedlings axenic culture increased from 18 482 pmol·g−1FW (fresh weight) after adding...

Abstract To identify transcription factors (TFs) involved in jasmonate (JA) signaling and plant defense, we screened 1,534 Arabidopsis (Arabidopsis thaliana) TFs by real-time quantitative reverse transcription-PCR for their altered transcript at 6 h following either methyl JA treatment or inoculation with the incompatible pathogen Alternaria brassicicola. We identified 134 that showed a significant change expression, including many APETALA2/ethylene response factor (AP2/ERF), MYB, WRKY, NAC...

Plants are sessile organisms that gauge stressful conditions to ensure survival and reproductive success. While plants in nature often encounter chronic or recurring conditions, the strategies cope with those poorly understood. Here, we demonstrate involvement of ARGONAUTE1 microRNA pathway adaptation heat stress (HS memory) at physiological molecular level. We show miR156 isoforms highly induced after HS functionally important for memory. promotes sustained expression HS-responsive genes is...

Affymetrix ATH1 arrays, large-scale real-time reverse transcription PCR of approximately 2200 factor genes and other gene families, analyses metabolites enzyme activities were used to investigate the response Arabidopsis phosphate (Pi) deprivation re-supply. Transcript data analysed with MapMan software identify coordinated, system-wide changes in metabolism cellular processes. Phosphorus (P) led induction or repression > 1000 involved many A subset, including P uptake, mobilization organic...

The irregular xylem3 (irx3) mutant of Arabidopsis has a severe deficiency in secondary cell wall cellulose deposition that leads to collapsed xylem cells. irx3 mutation been mapped the top arm chromosome V near marker nga106. Expressed sequence tag clone 75G11, which exhibits similarity synthase, was found be tightly linked irx3, and genomic clones containing gene corresponding 75G11 complemented mutation. Thus, IRX3 encodes synthase component is specifically required for synthesis wall....

Abstract Comprehensive expression profiles of Arabidopsis (Arabidopsis thaliana) MIRNA genes and mature microRNAs (miRs) are currently not available. We established a quantitative real-time polymerase chain reaction platform that allows rapid sensitive quantification 177 primary miR transcripts (pri-miRs). The was used to detect phosphorus (P) or nitrogen (N) status-responsive pri-miR species. Several pri-miR169 species as well pri-miR398a were found be repressed during N limitation, whereas...

Mutants and transformants of tobacco ( Nicotiania tabacum L. cv Gatersleben 1) with decreased expression nitrate reductase have been used to investigate whether accumulation in the shoot acts as a signal alter allocation between root growth. (a) Transformants very low (1–3% wild‐type levels) activity had growth rates, protein, amino acid glutamine levels similar or slightly lower than nitrate‐limited wild‐type, but accumulated large amounts nitrate. These plants should resemble except...

In many higher plants, cellulose synthesis is inhibited by isoxaben and thiazolidinone herbicides such as 5-tert-butyl-carbamoyloxy-3-(3-trifluromethyl) phenyl-4-thiazolidinone. Semidominant mutations at the IXR1 IXR2 loci of Arabidopsis confer resistance. Isolation gene map-based cloning revealed that it encodes AtCESA3 isoform synthase. The two known mutant alleles contain point replace glycine 998 with aspartic acid, threonine 942 isoleucine, respectively. occur in a highly conserved...

Summary Arabidopsis seedlings were subjected to 2 days of carbon starvation, and then resupplied with 15 m sucrose. The transcriptional metabolic response was analyzed using ATH1 arrays, real‐time quantitative (q)RT‐PCR analysis >2000 transcription regulators, robotized assays enzymes from central metabolism metabolite profiling. Sucrose led within 30 min greater than threefold changes the transcript levels for >100 genes, including 20 ubiquitin‐targeting proteins, four trehalose...

Summary Proteaceae species in south‐western Australia occur on severely phosphorus (P)‐impoverished soils. They have very low leaf P concentrations, but relatively fast rates of photosynthesis, thus exhibiting extremely high photosynthetic phosphorus‐use‐efficiency ( PPUE ). Although the mechanisms underpinning their remain unknown, one possibility is that these may be able to replace phospholipids with nonphospholipids during development, without compromising photosynthesis. For six...

Massive changes in gene expression occur when plants are subjected to phosphorus (P) limitation, but the breadth of metabolic these conditions and their regulation is barely investigated. Nearly 350 primary secondary metabolites were profiled shoots roots P-replete P-deprived Arabidopsis thaliana wild type mutants central P-signalling components PHR1 PHO2, microRNA399 overexpresser. In type, levels 87 metabolites, including phosphorylated not 3-phosphoglycerate, decreased, whereas...