The user guide

Arabidopsis seeds can be germinated directly in soil or can be transferred to soil after germination in a germination medium. [Recommended soil: a 2/1 mixture of potting compost and sandy soil with artificial moisturing agent. Keep the soil constantly humid. Plants that have been grown for 3 to 4 weeks on a sucrose medium prior to transfer to soil generally develop better than soil-germinated plants.

Araflats consist of 51 pots, each offering the ideal soil volume for growing individual Arabidopsis plants to maturity. For optimal aeration of the rosettes, it is recommended to space neighboring Araflats a few centimeters apart. This should be done before placing the Aracon base over the plants, which is best done as soon as the stem appears and reaches a height of 5-15 cm. Proper spacing and timely placement of the Aracon base ensure adequate airflow around the rosettes, promoting healthy growth and maximizing seed yield.

Arabaskets are particularly useful for seed harvesting and mutant screening, providing flexibility and ease in handling plants. In the event of an insect infestation, especially in its early stages, affected plants can be quickly and easily removed when grown in Arabaskets, minimizing the risk to the surrounding plants.

To efficiently water plants stacked in growth chamber racks, use Aratrays placed
underneath the Araflats. This setup allows you to flood the plants, ensuring consistent moisture levels across all pots. Additionally, Aratrays make it more convenient to transport plants grown in Araflats, providing both ease of movement and effective watering in growth chambers.

The Arasystem is incredibly simple to use, with the Aracon at its core, consisting of an Aratube and Arabase. The Aratubes arrive as flat plastic sheets that need to be folded into tubes before use. Each tube features a lock-and-key system at the top and bottom, allowing for easy and secure closure. While the process may seem challenging at first, after practicing with one or two, you’ll find it easy to fold several hundred tubes within an hour.
Tip: Consider asking undergraduate students in your lab to assist with the folding process. Alternatively, you and about 5-6 colleagues can easily fold a box of 720 Aracons during a 30-minute coffee break.

1. Timing:
   ◦ Allow your Arabidopsis plants to grow until they have developed a fully matured rosette and the flowering stem reaches about 10 cm in height.
   ◦ Once the flowering stem is formed, the rosette will stop growing significantly. Note that the larger the rosette, the more seeds the plant is likely to produce. To encourage the formation of larger rosettes, it is recommended to grow the plants in cooler conditions (approximately 18–20°C) with shorter daylight cycles. The temperature can then be slightly increased to initiate flowering and seed set.
2. Placement of the Aracon:
   ◦ After the flowering stem has grown to about 10 cm in height, carefully place the Aracon base over the rosette. Ensure that there is at least 1 cm of space between the rosette leaves and the bottom of the Aracon base.
   ◦ Avoid pressing the Aracon base too firmly onto the rosette to prevent damage.
   ◦ Allow the flowering stem to grow an additional 10–15 cm out of the top of the
   inverted cone of the Aracon base, providing enough space for optimal growth and seed production.

Once the Aracon base is securely in place over the Arabidopsis rosette, you can proceed to insert the folded Aracon tube into the base.

• Positioning the Tube: Carefully insert the Aracon tube into the base, ensuring that the two small ventilation holes are positioned just above the edge of the Aracon base.
• Aligning the Tubes: The ventilation holes in the tubes are asymmetrically placed. To prevent
  flowering stems that may occasionally grow through these holes from interfering with
  neighboring tubes, align all the tubes in the same direction. This alignment helps maintain
  proper spacing and minimizes the risk of plants growing into surrounding tubes.

To grow Arabidopsis plants to maturity, it’s important to water them regularly by flooding from below. Here’s how to ensure proper watering:

• Flooding Method: Water the plants by flooding from below, making sure that no water
  leaks into the Aracons. If your greenhouse facilities do not support flooding, use
  Aratrays to facilitate this method.
• Moisture Management: Keep the soil consistently moist, but avoid leaving the plants in
  a flooded state. Instead, water them once or twice a week, ensuring that about 1 cm of
  water remains in the Aratray after watering.
• Plant Maintenance: When an Arabidopsis plant begins to grow out of the top of the
  Aracon tube, it is advisable to decapitate the plant to manage growth and focus
  resources on seed production.

1. Allow Plants to Fully Mature:
   ◦ Once seed set is complete, allow the plants to dry completely. This drying process is crucial for optimal seed formation and should not be rushed.
2. Enhance Desiccation:
   ◦ To speed up the desiccation process, you can increase the temperature by a few degrees in the growing environment. However, ensure that the temperature increase is gradual and controlled to avoid damaging the seeds.
3. Avoid Premature Harvesting:
   ◦ Do not harvest seeds while the plants and siliques are still green. Immature seeds tend to stick to the septa of the siliques and will not easily detach, leading to poor seed yield and quality.

By following these steps, you can ensure that your Arabidopsis seeds are fully matured and dry, making them easier to harvest and increasing their viability.

1. Ensure Complete Dryness:
   ◦ Wait until the plant is completely dry and has turned brown before beginning the harvest. This indicates that the seeds are mature and ready for collection.
2. Cut the Stem:
   ◦ Cut the stem just above the rosette, directly underneath the Aracon base.
3. Remove the Plant:
   ◦ Gently remove the plant from the Aracon by pulling it out in a pulsating
   motion. This technique helps to release all the seeds, which will fall into the Aracon base.
4. Collect the Seeds:
   ◦ Invert the Aracon base over a sheet of paper or a sieve to separate the
   seeds from any dead silique parts.
   ◦ Once separated, collect the seeds in a suitable container for storage.
   Following these steps will help you efficiently harvest your Arabidopsis seeds with minimal loss and contamination.

Prevention:

• Maintain Optimal Growing Conditions: Ensure that your greenhouse or growth room
  maintains consistent temperature and humidity levels to avoid creating environments
  conducive to insect infestations. Preventing condensation inside the Aracon tubes is
  key, as condensation can attract insects and promote mold growth.
• Monitor Environmental Conditions: Avoid high relative humidity, drastic temperature
  changes, and cold air movements, as these conditions can lead to condensation and
  increase the risk of insect infestations.

Management:

• Avoid Insecticides in Aracon Tubes: In the event of an insect infestation, do not
  spray insecticides directly into the ARACON tubes. Many insecticides contain sticky
  components that can cause seeds to adhere to the tube walls and potentially harm the
  Arabidopsis plants.
• Manual Removal: If an infestation occurs, consider manually removing affected plants
  or using non-chemical methods to manage the insects, ensuring the health and integrity of your Arabidopsis plants and seeds.

By following these guidelines, you can effectively prevent and manage insect infestations, ensuring healthy growth and optimal seed production.