Why do we perform plant experiments in space?
Two major objectives:
1) To investigate the response of plant against gravity
Present day plants (also called green plants -Viridiplantae in Latin) that live on land evolved from ancestors that used to live under water a long time ago. When plants started populating the land, they developed many new survival mechanisms. An example are the waxy leaves - to prevent the water loss. On
All living organisms that further evolved on land, plants also had to adapt to respond to Earth's gravity. That was a very important change from the previous state in which the algae ancestors were simply floating in the water. On the land, plants had to develop an unique structure to support their own weight. We are trying to understand how they evolved into that by looking at the way they "move".
Today we know that plants do "move" a lot even though for an untrained eye they may seem to be still. The first to talk about these movements was the famous Charles Darwin. He observed that for instance, plants' roots seem to always grow downwards towards the centre of Earth - we call this now gravitropism. Plants' shoots, on the other hand, seem to grow away from Earth, as if they are continuously looking for light - we call this phototropism. Plants and seedlings also circumnutate - move around in circles.
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And what can happen to plants if we turn off both gravity and light?
The knowledge about how plants detect the gravitational force and construct their support structure is useful for breeding productive crops. The space experiments taking place on Kibo are a great way to study that.
2) To see if plants can grow in space
Plants are an important part of our lives but confined environments such as space or analog research stations (Antarctica, Utah) make us truly appreciate their value. Growing them in space is particularly difficult because we don't know how plants behave in microgravity and how does that affect their development.
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