Non-structural Carbohydrate Analysis Research Articles

Diurnal metabolism of energy-cane and sugarcane: A metabolomic and non-structural carbohydrate analysis

Energy-cane is a cross breed between commercial sugarcane and S. spontaneum, a hybrid that has higher fiber content, low sucrose and greater productivity compared to commercial sugarcane hybrids. It has been recently shown that diurnal and seasonal changes impact several physiological characteristics of sugarcane. However, little is known about how the diurnal cycle affects the production of carbohydrates and metabolites in energy-cane. In the present study, we investigate the diurnal cycle of adult sugarcane and energy-cane by analyzing the carbohydrates and metabolites profiles of leaves and internodes. Our results show fluctuations in the soluble sugars content (sucrose, glucose and fructose) and the metabolites profile throughout of day, which indicates different growth strategies and carbon use among these cultivars. In addition, a high concentration of starch was observed in the mature internodes of energy-cane. Some biological pathways related to biomass production, such as the phenylpropanoid pathway, were more active in energy-cane compared to sugarcane. Our results reveal that sugarcane and energy-cane metabolism are different throughout the day, a better understanding of the metabolism of these cultivars opens the possibility of creating more efficient plants through breeding.

Analysis of Non-Structural Carbohydrates and Xylem Anatomy of Leaf Petioles Offers New Insights in the Drought Response of Two Grapevine Cultivars.

In grapevine, the anatomy of xylem conduits and the non-structural carbohydrates (NSCs) content of the associated living parenchyma are expected to influence water transport under water limitation. In fact, both NSC and xylem features play a role in plant recovery from drought stress. We evaluated these traits in petioles of Cabernet Sauvignon (CS) and Syrah (SY) cultivars during water stress (WS) and recovery. In CS, the stress response was associated to NSC consumption, supporting the hypothesis that starch mobilization is related to an increased supply of maltose and sucrose, putatively involved in drought stress responses at the xylem level. In contrast, in SY, the WS-induced increase in the latter soluble NSCs was maintained even 2 days after re-watering, suggesting a different pattern of utilization of NSC resources. Interestingly, the anatomical analysis revealed that conduits are constitutively wider in SY in well-watered (WW) plants, and that water stress led to the production of narrower conduits only in this cultivar.

Large-scale protein analysis of European beech trees following four vegetation periods of twice ambient ozone exposure.

This study provides useful information on how European beech, an economically and ecologically important tree species, reacts on the molecular level to increased ozone concentrations expected in the near future. The main emphasis in the present study was placed on identifying differentially abundant proteins after long-term ozone exposure under climatically realistic settings, rather than short-term responses or reactions under laboratory conditions. Additionally, using nursery-grown beech trees, we took into account the natural genotypic variation of this species. As such, the results presented here provide information on molecular responses to ozone in an experimental plant system at very close to natural conditions. Furthermore, this proteomic approach was supported by previous studies on the present experiment. Ultimately, the combination of this proteomic approach with several approaches including transcriptomics, analysis of non-structural carbohydrates, and morphological effects contributes to a more global picture of how beech trees react under increased ozone concentrations.

Effects of simultaneous ozone exposure and nitrogen loads on carbohydrate concentrations, biomass, and growth of young spruce trees (Picea abies)

Spruce saplings were grown under different nitrogen fertilization regimes in eight chamberless fumigation systems, which were fumigated with either charcoal-filtered (F) or ambient air (O3). After the third growing season trees were harvested for biomass and non-structural carbohydrate analysis. Nitrogen had an overall positive effect on the investigated plant parameters, resulting in increased shoot elongation, biomass production, fine root soluble carbohydrate concentrations, and also slightly increased starch concentrations of stems and roots. Only needle starch concentrations and fine root sugar alcohol concentrations were decreased. Ozone fumigation resulted in needle discolorations and affected most parameters negatively, including decreased shoot elongation and decreased starch concentrations in roots, stems, and needles. In fine roots, however, soluble carbohydrate concentrations remained unaffected or increased by ozone fumigation. The only significant interaction was an antagonistic effect on root starch concentrations, where higher nitrogen levels alleviated the negative impact of ozone.

Les sucres chez l'oignon cultivéin vitro

Summary Enzymatic analysis of non structural carbohydrates in the onion bulb has been performed with plants cultured in vitro. Sucrose concentration in the culture medium ranged from 10 to 120 g/l and was responsible for morphological and biochemical modifications. The most significant differences were observed between plants either induced or not to bulbing by light treatments (F or F + i). Onion tissues can store great amounts of exogenous sucrose in turning it into fructans. Incandescent light inducing improves fructans polymerization. Fructans content and dormancy level were not related in our experiments on vitrobulbs.

Rapid Extraction and Analysis of Nonstructural Carbohydrates in Plant Tissues

Considerable time is necessary to determine the nonstructural carbohydrates (i.e., glucose, fructose, sucrose, starch) in plant tissues and some methods used for this purpose lack specificity. Two steps in such assays typically occupy much of the assay time: sample drying and homogenization/centrifugation. A laboratory method was therefore developed to carry out such assays without either of these steps. The new method involved separation of the ethanol‐soluble carbohydrates from disks or slices of plant tissue with hot aqueous ethanol and the in situ conversion of starch to glucose by enzymes. The amount of ethanol‐soluble sugars and the glucose released from the tissue during the starch digestion were then determined in a microplate assay using an enzyme‐coupled colorimetric reaction which was highly specific for glucose. The two starch‐degrading enzymes (α‐amylase and amyloglucosidase) and short digestion times (1.5 h) utilized in this method were selected to quantitatively release glucose from the starch in these samples without digesting significant amounts of β‐glucans. Results obtained with this technique were found to compare favorably with those obtained by homogenization of cotton (Gossypium hirsutum L.) leaf tissue. Besides cotton, this method has been successfully used to analyze soluble carbohydrates from a variety of other plant species. By this method it is possible to analyze plant samples two to five times faster than methods which employ sample drying and homogenization.