User's Guide

Grow Arabidopsis in suitable light conditions (e.g. 16h. light/8h. dark). Artificial light sources like Hg or Na bulbs give very satisfying results with most ecotypes (some ecotypes - e.g. C24 - appear to have problems with some tube lights).

Keep the relative humidity at about 60 - 70% for an optimal seed set.

Grow your Arabidopsis plants in a temperature stable environment at about 22°C. Temperatures higher than 25°C will strongly inhibit fertilisation of the Arabidopsis plants.

Water the plants regularly by flooding from below. If greenhouse facilities do not allow flooding of the plants, then use ARATRAYs. Keep the soil moist, but do not leave the plants constantly flooded. Rather, water them once or twice a week, leaving about 1cm of water in the ARATRAY.

Active pest control is very important. Keep the growth chamber clean and remove old plants as soon as possible after seed harvesting. Try not to bring in plants grown in other rooms - they could be a source of insect infestation! The use of autoclaved soil mixtures can help prevent certain insect infestations. Preventive insecticide spraying can best be done just before the first flowering stem comes up on the rosette. It is advisable to clear out the growth room once or twice a year and clean thoroughly with desinfectant products. By far the best seed setting conditions are reached by growing plants in small growth rooms or greenhouses that can be thoroughly desinfected after each growth cycle.

Each box of 720 ARACONs and each ARASYSTEM 360 KIT contains a correctly folded ARATUBE as an example.

Fold the ARATUBE as follows:

• First, you have to close the central lock of the tube. Take the sheet and hold it with both hands like you would hold a book while reading it (look through the sheet into the palms of your hands). The locking tabs should be on the left, and the two small ventilation holes should be near your body. Your left hand should be holding the lower part of the tube; your right hand should be in the middle of the tube, above your left hand. Your left thumb should be just under the central lock tab, at the left edge of the sheet. Your right thumb should be at the right edge of the sheet, in the middle of the central lock.
• Now, with your left thumb, fold the lower left part of the tube towards you (so that you now see your left thumbnail). Next, with your right thumb, fold the central part of the lock towards you (so that you now see your right thumbnail) and slip the right lock under the left part of the central lock tab. In the same movement, the left central lock tab should have slipped inside the right part of the tube.
• The bottom part of the central lock is now fixed, and you need to close the top part of the central lock. Therefore, with the bottom part of the lock closed, hold the tube with both hands just under the top of the lock. (The right part of the lock should be out towards you. If it is not, with your left thumb, press the tube firmly just under the top of the central lock and pull the right part of the tube out towards you.) Now, slide the right top part of the lock under the left edge of the lock. The central lock is now fixed.
• Finally, close the small locks at both ends of the tube by pressing the tabs with your thumbs into the corresponding holes. (The finished tube may have a couple of bumps or creases in it: a few gentle pushes should smooth it out into perfect shape!) The ARATUBE is now completely folded.

After the flowering stem is about 10 cm high (and not before), place the ARACON base over the rosette, leaving at least 1cm between the rosette leaves and the bottom of the base. Do not press the ARACON base too firmly onto the rosette

Allow the flowering stem to grow about 10-15 cm out of the top of the inverted cone of the base part of the ARACON.

Now place the folded ARACON tube into the base over the Arabidopsis plant. The tube should be placed so that the two small ventilation holes are placed just above the edge of the ARACON base. The ventilation holes in the tubes are placed asymmetrically, so that aligning all the tubes in the same direction will prevent stems that occasionally grow through these holes from growing into the surrounding tubes.

Allow the plant to grow to maturity, watering the plants regularly by flooding from below. Make sure no water leaks into the ARACONs. If greenhouse facilities do not allow flooding of the plants, then use ARATRAYs. Keep the soil moist but do not leave the plants constantly flooded. Rather, water them once or twice a week, leaving about 1 cm of water in the ARATRAY.

When an Arabidopsis plant starts to grow out of the top of an ARACON tube, decapitate the plant.

When seed set is finished, allow the plants to dry completely. The diseccation proces can be enhanced by increasing the temperature a few degrees. Seeds should not be harvested when the plants and the siliques are still green. The immature seeds will adhere to the septa of the siliques and will not fall down easily.

When the plant is completely dry and brown, cut the stem just above the rosette, under the ARACON base.

Remove the plant from the ARACON in a pulsating fashion.

All the seeds will fall into the ARACON base. Invert the ARACON base over a sheet of paper or over a sieve to separate the seeds from dead silique parts. Collect the seeds in a suitable holder.

Try to prevent insect infestations at all time, as described above. In case of insect infestations, never spray insecticides into the ARACON tubes. The insecticides often contain sticky components that will make seeds stick to the ARACONs and which can have a negative effect on Arabidopsis growth.

Avoid condensation in the ARACON at all times. The ventilation holes prevent condensation in normal growth conditions. But condensation can occur in case of high relative humidities, drastic temperature changes, cold air movements and insect infections. Therefore always avoid these conditions in your greenhouse or growth room.