Global gene expression was analyzed in Arabidopsis (Arabidopsis thaliana) by microarrays comprising 21,500 genes. Leaf segments derived from phosphorus (P)-starved and P-replenished plants were incubated with or without sucrose (Suc) to obtain tissues contrasting combinations of P carbohydrate levels. Transcript profiling revealed the influence two factors individually interactions between P- sugar-dependent regulation. A large number transcripts changed more than 2-fold: In response...

Plants have evolved a number of adaptive strategies to cope with fluctuations in phosphorus (P) supply. The current knowledge the transcriptional regulation P-starvation response plants is limited. However, one MYB-related transcription factor, PHR1, known be involved response. In this paper, we characterize T-tagged phr1 knockout mutant and series transgenic plant lines which over-express PHR1 wild type (WT) background. has an altered phosphate (Pi) allocation between root shoot;...

An adhesive bonding technique for wafer-level sealing of SU-8 based lab-on-a-chip microsystems with integrated optical components is presented. Microfluidic channels and components, e.g. waveguides, are fabricated in cross-linked sealed a Pyrex glass substrate by means an intermediate layer 950k molecular weight poly-methylmethacrylate (PMMA). Due to lower refractive index PMMA (n = 1.49 at λ 600–900 nm) this preserves waveguiding the structures 1.59 633 combination good microfluidic...

A new starch-degrading enzyme activity is induced by storage of potato (Solanum tuberosum L.) tubers at low temperatures (L. Hill, R. Reimholz, Schroder, T.H. Nielsen, M. Stitt [1996] Plant Cell Environ 14: 1223-1237). The cold-induced was separated from other amylolytic activities in zymograms based on iodine staining polyacrylamide gels containing amylopectin. similar band detected normal growth leaves, stems, and growing but present only warm-stored tubers. ion-exchange chromatography...

Tobacco seedlings were grown in nutrient agar at a range of ammonium nitrate concentrations either without added sucrose, or with 100 mol m –3 sucrose. In the absence nitrogen‐limited plants had increased levels glucose, fructose and decreased chlorophyll, protein, Rubisco activity, but level transcript for small subunit ( Rbc S) did not decrease compared nitrogen‐sufficient plants. When sucrose was to seedlings, there an increase glucose leaves, growth increased, chlorophyll protein...

Microbial community dynamics associated with manure hot spots were studied by using a model system consisting of gel-stabilized mixture soil and manure, placed between layers soil, during 3-week incubation period. The microbial biomass, measured as the total amount phospholipid fatty acids (PLFA), had doubled within 2-mm distance from soil-manure interface after 3 days. Principal-component analyses demonstrated that this increase was accompanied reproducible changes in composition PLFA,...

Some species exhibit light activation of sucrose-phosphate synthase (SPS) in intact leaves. Twelve which vary extent modulation SPS were studied to identify factors regulate the enzyme situ. Leaves harvested and darkness, was assayed under high substrate (Vmax) or limiting conditions (in presence th inhibitor inorganic phosphate). The tested fell into three groups. In some (Group I; barley maize) involved an increase Vmax enzyme. other II; spinach, swiss chard, sugarbeet, broad bean) had no...

Abstract Background Gene silencing vectors based on Barley stripe mosaic virus (BSMV) are used extensively in cereals to study gene function, but nearly all studies have been limited genes expressed leaves of barley and wheat. However since many important aspects plant biology root-expressed we wanted explore the potential BSMV for root tissues. Furthermore, newly completed genome sequence emerging cereal model species Brachypodium distachyon as well increasing amount EST information...

Growth, accumulation of sugars and starch, the activity enzymes involved in sucrose mobilization were determined throughout development sweet pepper fruits. Fruit was roughly divided into three phases: (1) an initial phase with high relative growth rate hexose accumulation, (2) a declining (3) ripening no further fresh weight increase hexoses, while starch degraded. Acid neutral invertase (EC 3.2.1.26) closely correlated to until inversly sucrose. specifically increased during ripening,...

Summary Fructose 2,6‐bisphosphate (fru‐2,6‐P 2 ) is a signalling metabolite that regulates photosynthetic carbon partitioning in plants. The content of fru‐2,6‐P Arabidopsis leaves varied response to activity with an abrupt decrease at the start photoperiod, gradual increase through day, and modest dark period. In suspension cells, increased unknown signal upon transfer fresh culture medium. This was blocked by either 2‐deoxyglucose or protein phosphatase inhibitor, calyculin A, effects A...

The in vivo phosphorylation of starch was studied Solanum tuberosum cv Dianella and Posmo. Small granules contain 25% more ester-bound phosphate per glucose residue than large granules. degree found to be almost constant during tuber development. Isolated discs synthesize from externally supplied at a significant rate. Tuber with [32P]orthophosphate incorporate radiolabeled phosphorus into the starch. level 32P incorporation is proportional amount synthesized. orthophosphate correlated de...

ABSTRACT These experiments investigate events involved in triggering sugar accumulation the cold tubers of Solanum tuberosum L. cv. Desirée. Sugar content, 14 C‐glucose metabolism, metabolite levels and activities sucrose phosphate synthase (SPS) starch‐degrading enzymes were followed after transfer to 4°C. (i) Net began between 2 4 d. By 10 d, reducing sugars also increasing. From 20 d onwards, slowed. Sucrose fell, but continued increase. (ii) To measure unidirectional synthesis, U‐[...

MicroRNAs (miRNAs) are short RNA chains (20-24 bp) which emerging as important regulators of gene expression. miRNAs encoded by specific genes, and in Arabidopsis, 190 genes have presently been identified. It has shown that miR399 is essential for the phosphate starvation response, recent studies transcriptional changes a number additional response to shortage phosphate. In this study, global profiles miRNA shoots Arabidopsis plants grown on limited or full nutrient combination with sucrose...

Transfer of potato tubers to low temperature leads after 2–4 d a stimulation sucrose synthesis, decline hexose‐phosphates and change in the kinetic properties, appearance new form phosphate synthase (SPS). Antisense co‐suppression transformants with 70–80% reduction SPS expression have been used analyse contribution control cold sweetening. The rate synthesis cold‐stored was investigated by measuring accumulation sugars, injecting labelled glucose high specific activity into intact tubers,...

Thermal nanoimprint lithography (NIL) of the cyclic olefin copolymeric thermoplast Topas® is demonstrated. highly UV-transparent, has low water absorption, and chemically resistant to hydrolysis, acids organic polar solvents which makes it suitable for lab-on-a-chip applications. In particular, micro systems made optical bio-detection since waveguides UV-light can be directly in Topas®. this article full process sequences spin coating onto 4 in. silicon wafers, NIL stamp fabrication with...

Carbohydrate metabolism was investigated in barley leaves subjected to drought or osmotic stress induced by sorbitol incubation. Both and resulted accumulation of hexoses, depletion sucrose starch, 5-10-fold increase the level regulatory metabolite fructose-2,6-bisphosphate (Fru-2,6-P2). These changes were paralleled an increased activity ratio fructose-6-phosphate,2-kinase / fructose-2,6-bisphosphatase (F2KP). The drought-induced carbohydrate content Fru-2,6-P2 reversed upon re-watering....

The transcription factor PHR1 (PHOSPHATE STARVATION RESPONSE 1; encoded by gene At4g28610) is central for adaptation to phosphate deficiency in Arabidopsis (Arabidopsis thaliana). A rapid turnover of pools the leaves essential energy transfer and metabolism within photosynthesis, consequently, we hypothesized that needed high-light stress during P deficiency. We analyzed three plant lines: wild-type, a transgenic overexpressor line knockout mutant, phr1. plants were grown under...

•Circadian (phospho)proteomics time courses of plants with or without functional clock.•Most protein abundance/phosphorylation rhythms require a transcriptional oscillator.•The majority rhythmic phosphosites peak around subjective dawn ("phospho-dawn").•A phosphorylated serine the metabolic enzyme F2KP has relevance. Twenty-four-hour, circadian control many eukaryotic mRNA levels, whereas levels their more stable proteins are not expected to reflect RNA rhythms, emphasizing need test...