Fig. 1.

Design of the three experimental protocols used to study sucrose transporter genes expression and sugar allocation in source and sinks organs of A. thaliana grown hydroponically. Photographs of plants (A. thaliana ecotype ‘Columbia’) at the six principal growth stages in the hydroponic system: Y young stage, D + 31 after sowing; A adult stage, D + 48 after sowing; IE inflorescence stage, D + 60 after sowing; F flowering stage, D + 70 after sowing; SR silique ripening, D + 98 after sowing and SH silique harvest, D + 125 after sowing. The different stages are defined as described in Boyes et al. (2001) and indicated on the top of each photograph (a). Y, A, and IE correspond to the vegetative phase, and F, SR, and SH correspond to the reproductive phase of A. thaliana plant development. Plants were harvested at each time point to perform the ‘developmental experiment’. Schematic representation of the 24-h cycle protocol applied on 31 day-old plants (young stage, Y) (b). Roots and rosettes of plants were harvested successively at 9, 13, 17, 21, 1, and 5 h (light 9–19 h, dark, 19–9 h). Schematic representation of the osmotic stress protocol applied (c). After sowing, stressed plants grew in nutrient medium during 24 days. Osmotic stress was applied by gradual addition of polyethylene glycol (+ 0.5% PEG) in nutrient medium every 2 days, from D + 24 to D + 32, until the medium reached 2.5% PEG. During the rehydration phase starting at D + 35, medium with PEG was removed and control medium was added. At the end of the stress (D + 35) and after the rehydration phase (D + 42), control and stressed plants were harvested (n = 5) for further analyses