Hot, Hotter, Hottest

By Sci4V Oppy

Day 4 Heat Stress Investigation

We are trying to figure out why the plants on the ISS died. We think it was because they were too hot. That made them shrivel up because they dried out. All the moisture got sucked out of them. Kind of like a drought.

The Control conditions were:

• Temperature: 28.2°C
• Humidity: 19.51%
• CO2: 28 ppm (we think this sensor is not working)
• Light: 1147 LUX

Day 4 Arabidopsis seedlings Control

The seedlings all germinated and have open, green cotyledons, healthy looking hypocotyls and roots.

In the Experimental conditions (Heat Stressed):

• Temperature: 42.8°C
• Humidity: 2.73%
• CO2: 1687 ppm
• Light: 4402 LUX

Day 4 Arabidopsis seedlings Experimental (Heat Stressed)

These seedlings have germinated but the hypocotyls and roots  look like they are drying out. Some of the cotyledons are small and white and others are still in the testa. Even the experimental seedlings cotyledons that are out of the testa have not opened up.

We also noticed that the control hypocotyls are white and the experimentals are clear.

The gel (growth media) in the experimental plates seems to be drying out. It looks thinner, has lots of little white dots and is peeling away from plate. We think the water is evaporating from the gel with the heat. We also noticed that the experimental plates were lighter weight. We massed them and found a 10 gram difference. That is equal to 10 ml of water!