Search results for " sucrose"

Partitioning of Sorbitol and Sucrose Catabolism within Peach Fruit

2002

The peach (Prunus persica (L.) Batsch (Peach Group)) fruit is a sink organ comprised of different types of tissue, which undergoes three distinct developmental stages during the growth season. The objective of this study was to characterize the activity and partitioning of sorbitol and sucrose catabolism within 'Encore' peach fruit to determine whether the two forms of translocated carbon play different roles in the various fruit tissues and/or stages of development. Sorbitol catabolic activity was defined as the sum of NAD-dependent sorbitol dehydrogenase (SDH) and sorbitol oxidase (SOX) activities, whereas sucrose catabolic activity was defined as the sum of sucrose synthase (SS), soluble…

Carbohydrate metabolism of vegetative and reproductive sinks in the late-maturing peach cultivar ‘Encore’

1999

Activities of NAD(+)-dependent sorbitol dehydrogenase (SDH), sorbitol oxidase (SOX), sucrose synthase (SS), acid invertase (AI), and neutral invertase (NI) in 'Encore' peach (Prunus persica L.) fruits and developing shoot tips were assayed during the growing season to determine whether carbohydrate metabolizing enzymes could serve as indicators of sink strength. In fruit flesh, SS activity was detected during Stage I of growth, when cells were actively dividing, and SDH activity was detected during Stage III, when cells were actively enlarging. Acid invertase activity was detected during Stage I and showed a closer correlation with relative increase in fruit weight during the growing season…

Cryopreservation of white mulberry (Morus alba L.) by encapsulation-dehydration and vitrification

2011

Shoot apices of in vitro-grown plantlets of white mulberry, Morus alba L. cv Florio, were cryopreserved using either encapsulation-dehydration or vitrification. For encapsulation-dehydration, alginate beads containing apices were dehydrated for 1, 3, 5 or 7 days in a liquid medium containing various sucrose concentrations (0.5, 0.75, 1.0 or 1.25 M). Bead desiccation was performed using silica gel for either 0, 4, 6, 8, 9 or 14 h. For vitrification, apices were directly immersed for either 5, 15, 30 or 60 min in a vitrification solution (PVS2). Following encapsulation-dehydration, treatment of alginate beads with 0.75 M sucrose was more effective in promoting re-growth of explants after imme…

Effect of drought on sorbitol and sucrose metabolism in sinks and sources of peach

2000

In peach (Prunus persica [L.] Batsch.), sorbitol and sucrose are the two main forms of photosynthetic and translocated carbon and may have different functions depending on the organ of utilization and its developmental stage. The role and interaction of sorbitol and sucrose metabolism was studied in mature leaves (source) and shoot tips (sinks) of'Nemaguard' peach under drought stress. Plants were irrigated daily at rates of 100, 67, and 33% of evapotranspiration (ET). The relative elongation rate (RER) of growing shoots was measured daily. In mature leaves, water potential (ψ w ), osmotic potential (ψ s ), sorbitol-6-phosphate dehydrogenase (S6PDH, EC 1.1.1.200), and sucrose-phosphate synt…

Activities of Sucrose and Sorbitol Metabolizing Enzymes in Vegetative Sinks of Peach and Correlation with Sink Growth Rate

1999

Terminal portions of `Flordaguard' peach roots [Prunus persica (L.) Batsch] were divided into six segments and the activities of NAD+-dependent sorbitol dehydrogenase (SDH), sorbitol oxidase (SOX), sucrose synthase (SS), soluble acid invertase (AI), and soluble neutral invertase (NI) were measured in each segment 10, 15, and 20 days after seed germination. The same type of experiment was conducted with terminal portions of `Flordaguard' and `Nemaguard' peach shoots except that one of the six segments consisted of the leaflets surrounding the apex. Independent of the age of individual roots, activities of SDH and AI were consistently highest in the meristematic portion and decreased with tis…

Comparative toxicity and cell-tissue distribution study on nanoparticular iron complexes using avian embryos and HepG2-cells

2007

In this study the toxicity and intracellular availability of iron from iron dextran (FeD), iron sucrose (FeS), and iron gluconate (FeG) was compared in organs of avian (turkey) embryos and in isolated cells (HepG2) in cell culture. Iron uptake was more pronounced in embryonic liver than in renal tissue. Cellular iron uptake in liver and kidney was more or less similar for the different compounds. Only some experiments showed slightly greater iron concentrations in liver and kidney with FeG compared with FeD and FeS. Significant differences were found in the survival ratios of the eggs and the embryo weights depending on the type of iron complex administered. The rank order of toxicities was…

Medicago truncatula

2012

In plants, long distance transport of sugars from photosynthetic source leaves to sink organs comprises different crucial steps depending on the species and organ types. Sucrose, the main carbohydrate for long distance transport is synthesized in the mesophyll and then loaded into the phloem. After long distance transport through the phloem vessels, sucrose is finally unloaded towards sink organs. Alternatively, sugar can also be transferred to non‐plant sinks and plant colonization by heterotrophic organisms increases the sink strength and creates an additional sugar demand for the host plant. These sugar fluxes are coordinated by transport systems. Main sugar transporters in plants compri…

Carbohydrate Metabolism and Source-Sink Relationships in Peach

2011

A growing plant can be viewed as a collection of carbohydrate sinks competing with each other for the available photosynthate supplied by the exporting leaves. Differences in sink strength often result in changes in the ability of various organs to compete for the available food determining final tree growth. A series of experiments have been conducted in peach to study changes and regulation of carbohydrate metabolism in growing organs and get a better understanding of the link between carbohydrate metabolism, sink strength, carbon partitioning and overall tree growth. Along with sucrose, sorbitol represents the major photosynthetic product and the main form of translocated carbon in peach…

Characterization of Sicilian Olive Genotypes by Multivariate Analysis of Leaf and Fruit Chemical and Morphological Properties

2013

Leaf and fruit size and shape were measured and mannitol, glucose, sucrose and malic acid were quantified in leaf, bark and fruit of 25 Sicilian olive genotypes. Multivariate analysis was used to individuate groups with similar chemical composition and morphological traits suggesting potential for stress tolerance and/or oil yield and quality. Mannitol content varied greatly among genotypes and was the most abundant carbohydrate in leaf and bark, whereas glucose was the most abundant in fruit. Sucrose and malic acid were generally low indicating a marginal role in olive tissues. Mannitol and glucose were directly related in both leaf and fruit tissues. Genotypes also differed for carbohydra…

Water Dynamics in Biological Systems investigated using Neutron Scattering Techniques

Living systems can not survive in absence of the water environments which play a fundamental role in living functions. Thus in the scienti?c community many studies were and are addressed to characterize water and its dynamics properties in biological systems. However, a clear description of water in such systems has been not reached yet. In fact, the investigations performed with di?erent techniques - those based on Nuclear Magnetic Resonance or those based on Neutron Scattering - look at di?erent di?usive motions and interactions water-biomolecules, leading controversial results and hence generating many debates between scientists. In this thesis we support the idea that two water populati…