Bone like hydroxyapatite (nHAp) was synthesized via an in situ biomimetic process in presence of wheat starch. The effect of polymer concentration alteration on the final structure of nHAp was investigated. Formation of the nHAp at room temperature was confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Size and morphology of the nHAp samples were character...

Although there is a great wealth of data supporting the occurrence of simultaneous synthesis and breakdown of storage carbohydrate in many organisms, previous 13CO2 pulse-chase based studies indicated that starch degradation does not operate in illuminated Arabidopsis leaves. Here we show that leaves of gwd, sex4, bam4, bam1/bam3 and amy3/isa3/lda starch breakdown mutants accumulate higher leve...

Reasons for the variable amylose content of endosperm starch from waxy cultivars of barley (Hordeum vulgare) were investigated. The mature grains of most such cultivars contain some amylose, although amounts are much lower than in wild-type cultivars. In these low-amylose cultivars, amylose synthesis starts relatively late in grain development. Starch granules in the outer cell layers of the en...

Debranching enzymes, which hydrolyze α-1 and 6-glucosidic linkages in α-polyglucans, play a dual role in the synthesis and degradation of starch in plants. A transposon-inserted rice mutant of isoamylase3 (isa3) contained an increased amount of starch in the leaf blade at the end of the night, indicating that ISA3 plays a role in the degradation of transitory starch during the night. An epitope...

Amylose synthesis was obtained in vitro from purified Chlamydomonas reinhardtii starch granules. Labeling experiments clearly indicate that initially the major granule-bound starch synthase extends glucans available on amylopectin. Amylose synthesis occurs thereafter at rates approaching or exceeding those of net polysaccharide synthesis. Although these results suggested that amylose originates...

Adenine nucleotides are of general importance for many aspects of cell function, but their role in the regulation of biosynthetic processes is still unclear. It was previously reported that decreased expression of plastidial adenylate kinase, catalysing the interconversion of ATP and AMP to ADP, leads to increased adenylate pools and starch content in transgenic potato tubers. However, the unde...

Potato starch offers several unique properties essential for nutrition, and numerous non-nutritional applications. First of all, it is the sole native starch of anionic character. For that reason, potato starch combines, for instance, with proteins forming various complexes considered as potential biodegradable plastics. Potato starch is, practically, the sole starch variety containing a consid...

Monensin was fed at 0 and 33 ppm in a crossover trial designed to determine the effect of this compound on ruminal and postruminal utilization of a corn-based diet and bacterial protein synthesis in abomasally fistulated steers. Monensin decreased (P greater than .10) ruminal true digestion of organic matter (OMc, corrected for bacterial cell synthesis) and apparent ruminal digestion of starch ...

Starch phosphorylase (SP) is an enzyme used for the reversible phosphorolysis of the alpha-glucan in plant cells. When compared to its isoform in an animal cell, glycogen phosphorylase, a peptide containing 78 amino acids (L78) is inserted in the centre of the low-affinity type starch phosphorylase (L-SP). We found that the amino acid sequence of L78 had several interesting features including t...

Plants deal with resource management during all their life. During the day they feed on photosynthetic carbon, sucrose, while storing a part into starch for night use. Careful control of carbon partitioning, starch degradation, and sucrose export rates is crucial to avoid carbon starvation, insuring optimal growth whatever the photoperiod. Efficient regulation of these key metabolic rates can g...