Abstract
Background: Arabidopsis thaliana is now the model organism for genetic and molecular plant
studies, but growing conditions may still impair the significance and reproducibility of the
experimental strategies developed. Besides the use of phytotronic cabinets, controlling plant
nutrition may be critical and could be achieved in hydroponics. The availability of such a system
would also greatly facilitate studies dealing with root development. However, because of its small
size and rosette growth habit, Arabidopsis is hardly grown in standard hydroponic devices and the
systems described in the last years are still difficult to transpose at a large scale. Our aim was to
design and optimize an up-scalable device that would be adaptable to any experimental conditions.
Results: An hydroponic system was designed for Arabidopsis, which is based on two units: a seedholder
and a 1-L tank with its cover. The original agar-containing seed-holder allows the plants to
grow from sowing to seed set, without transplanting step and with minimal waste. The optimum
nitrate supply was determined for vegetative growth, and the flowering response to photoperiod
and vernalization was characterized to show the feasibility and reproducibility of experiments
extending over the whole life cycle. How this equipment allowed to overcome experimental
problems is illustrated by the analysis of developmental effects of nitrate reductase deficiency in
nia1nia2 mutants.
Conclusion: The hydroponic device described in this paper allows to drive small and large scale
cultures of homogeneously growing Arabidopsis plants. Its major advantages are its flexibility, easy
handling, fast maintenance and low cost. It should be suitable for many experimental purposes.