Delaying Germination of Seeds Using Far-Red Light

ASOP-0005 Version 1

Table of Contents

1.0: Purpose

The purpose of this SOP is to provide instructions on how to impose dormancy in seeds of Arabidopsis thaliana using far-red light.  The original scientific technique was developed by the Gilroy Laboratory at the University of Wisconsin-Madison to halt germination of A. thaliana until a planned experiment start date and to mitigate the one time stress of rocket launch. For example, in a planned experiment that compares the growth of A. thaliana on the ISS in parallel with A. thaliana on Earth, imposing seed dormancy allows a scientist on the ISS and the scientist on Earth to coordinate a definite start to the beginning of germination after the seeds travel to space. This also allows the seeds to be affected less by the one-time associated stressors of launch.

astrobotany seeds arabidopsis rocket launch
Fig. 1.1: Astrobotany.com cartoon graphic demonstrating seed dormancy during launch.

2.0: Safety

Standard laboratory personal protective equipment (PPE) should be worn when executing this technique.  Refer to Material Safety Data Sheets (SDS) for hazards and appropriate handling precautions.  Have a plan to safely navigate the dark room or space when the lights are off.   

3.0: Definitions and Acronyms

  • ASOP: Astrobotany Standard Operating Procedure

4.0: Materials

5.0: Equipment

  • Far-red LED lighting (e.g. CREE XP-E2 Far Red)
  • An extremely dark room or space (as little light as possible)
  • Timer

6.0: Procedure

  1. Select a room or space capable of reaching a darkness level where you are not be able to view an object (e.g. your hand) approximately 0.5 meters from your face with the lights turned off.
  2. Set up the far-red LED and place all aluminum foil and light-proof bags/materials in this room.
  3. Prepare seeds for the desired assay, as if getting ready to begin the experiment.  For example, sterilize the Arabidopsis thaliana seeds and sow them on prepared media in a 10 cm x 10 cm Petri dish.
  4. Shortly after preparing the seeds, bring them into the previously prepared room.
  5. Position the seeds closely underneath the turned off far-red LED light so the seeds will be receiving intense and total coverage from the far-red light.
  6. Shut the lights off, wait 5 seconds, then turn on the far-red LED light to irradiate the seeds.  Irradiate the seeds for no less than 5 minutes. 
  7. After 5 minutes, wrap the seeds completely and thoroughly with aluminum foil.  Then bag and seal the foil wrapped seeds.  Then bag and seal again (double bag). 
  8. Seeds can then be stored as they normally would- expose to light again to begin germination when desired.

7.0: References

Version History

  • Version 1 | Description: ASOP-0005 page created. | Effective: 27Jul2023
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