Presence of inulin in sunflower (Helianthus annuus L.) grown under high irradiance.

Fructans are important polysaccharides synthesized from sucrose which are present in about 12-15% of angiosperms. Sunflower (Helianthus annuus L.) is considered a non-fructan bearing plant even though its close relative, Helianthus tuberosus, accumulates the inulin type of the polymer in large amounts.

Sunflower: a potential fructan-bearing crop?

Grain filling in sunflower (Helianthus annuus L.) mainly depends on actual photosynthesis, being the contribution of stored reserves in stems (sucrose, hexoses, and starch) rather low. Drought periods during grain filling often reduce yield.

Sucrose signaling in plants: a world yet to be explored.

The role of sucrose as a signaling molecule in plants was originally proposed several decades ago. However, recognition of sucrose as a true signal has been largely debated and only recently this role has been fully accepted. The best-studied cases of sucrose signaling involve metabolic processes, such as the induction of fructan or anthocyanin synthesis, but a large volume of scattered information suggests that sucrose signals may control a vast array of developmental processes along the whole life cycle of the plant.

Sugar signaling of fructan metabolism: New insights on protein phosphatases in sucrose-fed wheat leaves.

Protein phosphatase type 2A (PP2A) activity is required for the sucrose induction of fructan metabolism in wheat leaves, as shown in experiments with the addition of the specific inhibitor okadaic acid (OA) together with sucrose. However, a decrease in total PP2A activity has been found along sucrose treatment. Here we analyze the effect of sucrose feeding to wheat leaves on PP2A activity profiles after Deae-Sephacel and Superose separation, in comparison with those of control leaves.

Protein phosphatase activity and sucrose-mediated induction of fructan synthesis in wheat.

In this work, we analyze protein phosphatase (PP) involvement in the sucrose-mediated induction of fructan metabolism in wheat (Triticum aestivum). The addition of okadaic acid (OA), a PP-inhibitor, to sucrose-fed leaves reduced fructosylsucrose-synthesizing activity (FSS) induction in a dose-dependent manner. The expression of the two enzymes that contribute to FSS activity, 1-SST (1-sucrose:sucrose fructosyltransferase, E.

Suboptimal temperature favors reserve formation in biennial carrot (Daucus carota) plants.

In response to suboptimal temperatures, temperate annual plants often increase root:shoot ratios, build-up carbohydrates and display typical morphological and anatomical changes. We know less about the responses of biennials such as carrot. As a model plant, carrot has the additional feature of two functionally and morphologically distinct root parts: the taproot, which stores carbohydrate and other compounds, and the fibrous root system involved in acquisition of water and nutrients.

Morphological plasticity of spring and winter wheats in response to changing temperatures.

Temperature change induces morpho-physiological responses, whose significance for plant function under this modified environmental condition is mostly unclear. Plastic responses to temperature changes from optimal (25°C) to chilling (5°C) conditions or vice versa, as compared with constant temperature treatments, were studied in spring and winter wheat. Plants grown at 5°C had smaller leaves, less stomata and larger root systems than their counterparts grown at 25°C.