The intracellular concentration of trehalose increases in the stationary-phase cells of Escherichia coli. The effects of trehalose on transcription in vitro by E. coli RNA polymerase were compared for two holoenzymes, Es and Es, which were reconstituted from purified core enzyme and either s (the major s at the exponential growth phase) or s (the essential s at the stationary growth phase), res...

We have studied the transport of trehalose and maltose in the thernophilic bacterium Thermus thermophilus HB27, which grows optimally in the range of 70 to 75 degrees C. The K(m) values at 70 degrees C were 109 nM for trehalose and 114 nM for maltose; also, a high K(m) (424 nM) was found for the uptake of sucrose. Competition studies showed that a single transporter recognizes trehalose, maltos...

Steinernema feltiae is a moderately freeze-tolerant entomopathogenic nematode which survives intracellular freezing. We have detected by gas chromatography that infective juveniles of S. feltiae produce cryoprotectants in response to cold acclimation and to freezing. Since the survival of this nematode varies with temperature, we analyzed their cryoprotectant profiles under different acclimatio...

Trehalose is a nonreducing sugar used as a reserve carbohydrate and stress protectant in a variety of organisms. While higher plants typically do not accumulate high levels of trehalose, they encode large families of putative trehalose biosynthesis genes. Trehalose biosynthesis in plants involves a two-step reaction in which trehalose-6-phosphate (T6P) is synthesized from UDP-glucose and glucos...

Trehalose, which plays important roles in resistance to abiotic stresses and preservation of biological activity plants, is synthesized by two key enzymes, trehalose-6-phosphate synthase (TPS) phosphatase (TPP). Therefore, the expressions TPS TPP genes directly affect trehalose synthesis stress plants. In this study, CkTPS CkTPP from Caragana korshinskii were identified, role adaptation desert ...

The sunflower stem weevil, Cylindrocopturus adspersus (LeConte), overwinters as a mature larva at the base of the stalk and in the root crown of cultivated sunflower plants. Sunflower stalks from fields known to be infested with C. adspersus larvae were collected in southeastern North Dakota in October 1991. Larvae from stalks kept outdoors accumulated a high whole-body concentration of trehalo...

The stabilization of ribonuclease A by alpha-alpha-trehalose was studied by preferential interaction and thermal unfolding. The protein is stabilized by trehalose at pH 2.8 and pH 5.5. Wyman linkage analysis showed increased exclusion of trehalose from the protein domain on denaturation. Preferential interaction measurements were carried out at 52 degrees C at pH 5.5 and 2.8, where the protein ...

A genomic DNA fragment encoding a putative maltooligosyltrehalose trehalohydrolase (NfMTH) for trehalose biosynthesis was cloned by the degenerate primer- PCR from cyanobacterium Nostoc flagelliforme. The ORF of NfMTH is 1,848 bp in length and encodes 615 amino acid residues, constituting a 70 kDa protein. The deduced amino acid sequence of NfMTH contains 4 regions highly conserved for MTHs. By...

Trehalose, a disaccharide accumulated by many microorganisms, acts as a protectant during periods of physiological stress, such as salinity and desiccation. Previous studies reported that the trehalose biosynthetic genes (otsA, treS, and treY) in Bradyrhizobium japonicum were induced by salinity and desiccation stresses. Functional mutational analyses indicated that disruption of otsA decreased...

cold hardiness is one of the most common adaptations of insects at low temperatures. to understand the cold hardiness strategy of beet armyworm, spodoptera exigua (hübner), six temperature treatments were tested on the last instar larvae. supercooling points of treatments were not significantly different. two sugars, glucose and trehalose, as well as three polyols, myo-inositol, glycerol and so...