Been growin’ the Arabidopsis seedlings in Eppendorf tubes filled with agar media. The young roots do what they do best and grow downwards through the agar media (this is called ‘gravitropism‘). The race is on though….if we don’t help them now they will be trapped in a plastic hell of diminishing nutrients.
That’s when we come to the rescue and clip the bottom of the agar tubes so that the growing roots can escape to freedom. This part of the process of growing Arabidopsis hydroponically is between the two earlier posts ‘Seed spotting‘ + ‘Green shoots emerging‘ and this later one: ‘Looking for roots‘. We use a tube cutter from VWR.
Once all the tubes are clipped, a puddle of hydroponic ‘root juice’ is added to the tray. This is double the strength of the hydroponic media used to make the agar in the tubes. We do this to help tease the roots down and out of the tube…it’s their reward for their escape to freedom.
Got a good crop this time…hopefully that’ll mean we can do lots of interesting experiments.
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Lets have a look at how our little Arabidopsis plants are getting on. These were the plants that were growing in the yellow ‘nursery’ boxes. The young seedlings are about two weeks old, now growing hydroponically in blackened boxes to keep the roots dark.
Here, were having a wee look to see if the roots have emerged from the bottom of the cut Eppendorf tubes. Yes ! there are roots coming out into the hydroponic media (a minimal medium without any sucrose).
The boxes are in environmentally controlled growth cabinets (Sniggers cabinets) where we can control light intensity and temperature and humidity. I have the plants growing in 12 hours of light and 12 hours of dark (12h LD) at 20oC. These are quite standard “lab” conditions. I suppose 12h LD would be equivalent to the equinoxes in Nature…..would we ever get 20oC in Scotland in March or September ? (I very much doubt!)
Time to check on how the seeds are doing after the seed spotting.
As you can see some are germinating….but not all.
Is there going to be enough plants for my experiment? I spotted around 250 seeds – it would be great if around half germinated.
After overfilling the tubes with the agar/growth media a cross is sliced into the agar with a sterile blade (see clip above). Doing this his will hopefully help the roots find a way down through the agar/growth media.
Then the Arabidopsis seeds (sterilised in bleach and suspended in sterile water) are pipetted onto the surface of the agar one-by-one (ok, maybe sometimes two-by two) – see clip below.
The trays are then sealed with micropore tape and that’s it – now to wait to see if the seeds germinate – should take around a week to see the emergence of the very young shoots.