Flowering is a crucial process that demands substantial resources. Carbon metabolism must be coordinated with development through a control mechanism that optimizes fitness for any physiological need and growth stage of the plant. However, how sugar allocation is controlled during the floral transition is unknown. Recently, the role of a CONSTANS (CO) ortholog (Cr-CO) in the control of the photoperiod response in the green alga Chlamydomonas reinhardtii and its influence on starch metabolism was demonstrated. In this work, we show that transitory starch accumulation and glycan composition during the floral transition in Arabidopsis thaliana are regulated by photoperiod. Employing a multidisciplinary approach, we demonstrate a role for CO in regulating the level and timing of expression of the GRANULE BOUND STARCH SYNTHASE (GBSS) gene. Furthermore, we provide a detailed characterization of a GBSS mutant involved in transitory starch synthesis and analyze its flowering time phenotype in relation to its altered capacity to synthesize amylose and to modify the plant free sugar content. Photoperiod modification of starch homeostasis by CO may be crucial for increasing the sugar mobilization demanded by the floral transition. This finding contributes to our understanding of the flowering process.

Effects of microwave energy and conventional heating on physical and chemical parameters of five edible oils and fats (virgin olive oil, olive oil, sunflower oil, high oleic sunflower oil, and lard) were investigated. These fats and oils were subjected to three well-controlled treatments:  heating in conventional electric oven, heating by microwave energy, and exposure to microwave energy, respectively. The effect of microwave heating on the visible spectrum, K 232 and K 270, density, viscosity, and squalene and trans-isomer contents of fats and oils was worse than that produced by heating the same fats in a conventional oven at the same temperature, time, surface/volume ratio, and light conditions. Subjecting fats and oils to microwave energy under the same conditions, but below 40 °C, did not produce considerable variations in the same parameters when compared to the original ones. Keywords: Microwave oven; heating effect; chemical and physical parameters; edible fats and oils

The effects of microwave treatments on the thermoxidative degradation of five edible fats and oils (sunflower oil, high oleic sunflower oil, virgin olive oil, olive oil, and lard) were determined. The samples were subjected to the following three well-controlled treatments:  (a) microwave heating, (b) heating in a conventional electric oven, and (c) exposure to microwave energy without heating. A comparative study was carried out on the deterioration of the oils as a result of microwave and conventional oven heating. Degradations were quantified by means of a combination of chromatographic techniques and related analytical index. Data analysis showed greater alterations in microwave-heated samples than in corresponding samples heated in a conventional oven. Finally, microwave energy, without heating (temperature lower than 40 °C), produced no oil alterations. Keywords: Microwave energy; conventional oven; heating effect; edible fats and oils; thermoxidative alteration