Abstract Trehalose-6-phosphate (T6P) is a proposed signaling molecule in plants, yet how it signals was not clear. Here, we provide evidence that T6P functions as an inhibitor of SNF1-related protein kinase1 (SnRK1; AKIN10/AKIN11) the group kinases. T6P, but other sugars and sugar phosphates, inhibited SnRK1 Arabidopsis (Arabidopsis thaliana) seedling extracts strongly (50%) at low concentrations (1–20 μ m). Inhibition noncompetitive with respect to ATP. In immunoprecipitation studies using...

Abstract Trehalose 6-phosphate (T6P) is an important regulator of plant metabolism and development. T6P content increases when carbon availability high, in young growing tissue, inhibits the activity Snf1-related protein kinase (SnRK1). Here, strong accumulation was found senescing leaves Arabidopsis (Arabidopsis thaliana), parallel with a rise sugar contents. To determine role senescence, altered by expressing bacterial synthase gene, otsA (to increase T6P), or phosphatase otsB decrease...

Summary The aim of this work was to evaluate the function isoamylase in starch granule biosynthesis Arabidopsis leaves. A reverse‐genetic approach used knockout AtISA1 , one three genes encoding isoamylase‐type debranching enzymes. mutant ( Atisa1 ‐1) lacks functional transcript and major activity (detected by native gels) crude extracts same is abolished mutation at DBE1 locus, which encodes a second protein, AtISA2. This consistent with idea that ISA1 ISA2 proteins are subunits enzyme vivo...

Abstract Trehalose 6-P (T6P) is a sugar signal in plants that inhibits SNF1-related protein kinase, SnRK1, thereby altering gene expression and promoting growth processes. This provides model for the regulation of by sugar. However, it not known how this operates under sink-limited conditions when tissue content uncoupled from growth. To test physiological importance model, T6P, SnRK1 activities, sugars, expression, were measured Arabidopsis (Arabidopsis thaliana) seedlings after transfer to...

Abstract Trehalose 6-phosphate (T6P) is a sugar signal that regulates metabolism, growth, and development inhibits the central regulatory SNF1-related protein kinase1 (SnRK1; AKIN10/AKIN11). To better understand mechanism in wheat (Triticum aestivum) grain, we analyze T6P content SnRK1 activities. levels changed 178-fold 1 to 45 d after anthesis (DAA), correlating with sucrose content. ranged from 78 nmol g−1 fresh weight (FW) pregrain filling, around 100-fold higher than previously reported...

The aim of this work was to understand the initial steps starch breakdown inside chloroplasts. In non-living endosperm germinating cereal grains, is initiated by alpha-amylase secreted from surrounding cells. However, loss Arabidopsis does not prevent chloroplastic (Yu, T.-S., Zeeman, S. C., Thorneycroft, D., Fulton, D. Dunstan, H., Lue, W.-L., Hegemann, B., Tung, S.-Y., Umemoto, T., Chapple, A., Tsai, D.-L., Wang, S.-M, Smith, A. M., Chen, J., and M. (2005) J. Biol. Chem. 280, 9773-9779),...

The strong regulation of plant carbon allocation and growth by trehalose metabolism is important for our understanding the mechanisms that determine yield, with obvious applications in crop improvement. To gain further insight on arrest feeding, we first established starch-deficient seedlings plastidic phosphoglucomutase1 mutant were similarly affected as wild type trehalose. Starch accumulation source cotyledons, therefore, did not cause starvation consequent growing zones. We then screened...

Several studies have suggested that debranching enzymes (DBEs) are involved in the biosynthesis of amylopectin, major constituent starch granules. Our systematic analysis all DBE mutants Arabidopsis thaliana demonstrates when any activity remains, granules still synthesized, albeit with altered amylopectin structure. Quadruple lacking four proteins (Isoamylase1 [ISA1], ISA2, and ISA3, Limit-Dextrinase) devoid instead accumulate highly branched glucans, distinct from previously described...

• The Arabidopsis basic region-leucine zipper transcription factor 11 (bZIP11) is known to be repressed by sucrose through a translational inhibition mechanism that requires the conserved control peptide encoded mRNA leader. function of bZIP11 has been investigated in over-expression studies, and found inhibit plant growth. addition sugar does not rescue growth phenotype. Here, was investigated. which regulates studied using large-scale dedicated metabolic analysis, biochemical assays...

The aim of this article is to provide an overview current models starch breakdown in leaves. We summarise the results our recent work focusing on Arabidopsis, relating them other field. Early biochemical studies containing tissues identified numerous enzymes capable participating degradation. In non-living endosperms germinated cereal seeds, proceeds by combined actions α-amylase, limit dextrinase (debranching enzyme), β-amylase and α-glucosidase. activities these regulation some respective...

Isoamylase-type debranching enzymes (ISAs) play an important role in determining starch structure. Amylopectin – a branched polymer of glucose is the major component granules and its architecture underlies semi-crystalline nature starch. Mutants several species lacking ISA1-subclass isoamylase are impaired amylopectin synthesis. Consequently, levels decreased aberrant soluble glucan (phytoglycogen) with altered branch lengths branching pattern accumulates. Here we use TAP (tandem affinity...

Summary Aphids are pests of chrysanthemum that employ plant volatiles to select host plants and ingest cell contents probe quality before engaging in prolonged feeding reproduction. Changes volatile nonvolatile metabolite profiles can disrupt aphid–plant interactions provide new methods pest control. Chrysanthemol synthase ( CHS ) from Tanacetum cinerariifolium represents the first committed step biosynthesis pyrethrin ester insecticides, but no biological role for chrysanthemol product...

Plants store volatile compounds in specialized organs. The properties of these storage organs prevent precarious evaporation and protect neighbouring tissues from cytotoxicity. Metabolic engineering plants is often carried out such as leaf mesophyll cells, which are abundant easily accessible by tools. However, not suitable for the hydrophobic compound sesquiterpenes engineered volatiles lost into headspace. In this study, we show that seeds Arabidopsis thaliana, naturally contain lipid...

Carbon signaling can override carbon supply in the regulation of growth. At least some this is imparted by sugar signal trehalose 6-phosphate (T6P) through protein kinase, SnRK1. This pathway regulates biosynthetic processes involved growth under optimal growing conditions. Recently, using a seedling system we showed that sub-optimal conditions, such as cold, T6P/ SnRK1 enables recovery following relief stress. The mechanism thus could be selected means improving low temperature tolerance....

Candeia (Eremanthus erythropappus (DC) McLeisch, Asteraceae) is a Brazilian tree, mainly occurring in the cerrado areas. From ethnobotanical information its essential oil known to have wound healing and nociceptive properties. These properties are ascribed result from sesquiterpene alcohol, (−)-α-bisabolol, which present at high concentrations this oil. Bisabolol highly valued by cosmetic industry because of antibacterial, anti-inflammatory, skin-smoothing Over past decades, timber has been...

Trehalose-6-phosphate (T6P) is an intermediate in the plant metabolic pathway that results trehalose production. T6P has been shown to inhibit sucrose nonfermenting-1-related protein kinase 1, which a major regulator of metabolism. The quantitation proven difficult due complexity matrix and low abundance tissues. aim this work was develop method for present Arabidopsis tissues, with capillary electrophoresis (CE) coupled electrospray ionization-mass spectrometry (MS) sheath liquid (SL)...

Plants produce a wide range of secondary metabolites. Within single species, chemotypes can be distinguished by the differences in composition Herein, we evaluated Nectandra megapotamica (Spreng.) and balance different classes metabolites to verify how significant plant metabolism are regarding chemotypes. We collected N. leaves from eight adult plants two Brazilian states. The essential oils ethanol/water extracts were analyzed GC-MS LC-DAD-MS, respectively. Histochemical tests performed,...

Phorodon humuli (Damson-hop aphid) is one of the major pests hops in northern hemisphere. It causes significant yield losses and reduces hop quality economic value. Damson-hop aphid currently controlled with insecticides, but number approved pesticides steadily decreasing. In addition, use insecticides almost inevitably results development resistant genotypes. An integrated approach to pest management cultivation therefore badly needed order break this cycle prevent selection strains few...